Tomato • Celery stock • Chlorella • FOS • Wheat Grass • Dandelion • Spinach • Fenugreek • Milk Thistle • Grapefruit pectin • Barley juice concentrate.
Brand name products often contain multiple ingredients. To read detailed information about each ingredient, click on the link for the individual ingredient shown above.
Below is general information about the effectiveness of the known ingredients contained in the product P2H. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
INSUFFICIENT RELIABLE EVIDENCE to RATE
Below is general information about the safety of the known ingredients contained in the product P2H. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
LIKELY SAFE ...when used orally and appropriately in food amounts (4819,4820,4821,5104,10166,10435,11134,11463,11986,92818). There is insufficient reliable information available about the safety of barley when used orally in medicinal amounts or when applied topically.
PREGNANCY: LIKELY SAFE
when used orally in amounts commonly found in foods (19).
PREGNANCY: POSSIBLY UNSAFE
when barley sprouts are consumed in relatively high doses.
Excessive amounts of barley sprouts should not be consumed during pregnancy (19).
LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when celery stems are consumed as food. ...when celery oil or seeds are consumed in amounts commonly found in foods. Celery seed has Generally Recognized as Safe (GRAS) status in the US (4912).
POSSIBLY SAFE ...when celery seed is used orally and appropriately in medicinal amounts, short-term (12). Celery seed powder has been safely used at doses up to 1500 mg daily for up to 6 weeks and 750 mg daily for up to 12 weeks. Celery seed extract has been safely used at doses up to 1340 mg daily for up to 4 weeks (106486,110755,112409,112411). ...when celery seed extract is used topically and appropriately, short-term (40988,41049,41052).
PREGNANCY: LIKELY UNSAFE
when celery oil or seeds are used orally in larger amounts; celery might have uterine stimulant or abortifacient effects (4,19,19104).
LACTATION:
There is insufficient reliable information available about the safety of medicinal amounts of celery during lactation; avoid using.
LIKELY SAFE ...when used orally and appropriately, short-term. Tablets and liquids containing chlorella 3-10 grams or 60-100 mL daily have been safely used in clinical studies lasting 2-3 months (5890,92130,92131). Also, chlorella extract 200-1800 mg daily has been safely used in clinical research for 4-6 weeks (10388,92132). There is insufficient reliable information available about the safety of chlorella when used topically.
PREGNANCY: POSSIBLY SAFE
when used orally and appropriately in medicinal amounts for up to approximately 28 weeks.
A commercially available chlorella supplement (Sun Chlorella A, Sun Chlorella Corp.) has been safely used in doses of 6 grams daily, starting during the 12-18th week of gestation and continuing until delivery (95013).
LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Dandelion has Generally Recognized As Safe (GRAS) status in the US (4912).
POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts (12). There is insufficient reliable information available about the safety of dandelion when used topically.
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using amounts greater than those in foods.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Fenugreek has Generally Recognized as Safe (GRAS) status in the US (4912).
POSSIBLY SAFE ...when the seed is used orally in medicinal amounts. Fenugreek seed powder 5-10 grams daily has been used with apparent safety for up to 3 years. Fenugreek seed extract 1 gram daily has been used with apparent safety for up to 3 months (7389,9783,18359,18362,49868,90112,90113,90117,93419,93420)(93421,93422,93423,96065,103285,108704).
CHILDREN: LIKELY SAFE
when used orally in amounts commonly found in foods (4912).
There is insufficient reliable information available about the safety of fenugreek when used in larger amounts. Unusual body and urine odor has been reported after consumption of fenugreek tea. Although the odor appears to be harmless, it may be misdiagnosed as maple syrup urine disease (9782,96068).
PREGNANCY: LIKELY UNSAFE
when used orally in amounts greater than those found in food.
Fenugreek has potential oxytoxic and uterine stimulant activity (12531). There are case reports of congenital malformations, including hydrocephalus, anencephaly, cleft palate, and spina bifida, after consumption of fenugreek seeds during pregnancy (96068). Consumption of fenugreek immediately prior to delivery may cause the neonate to have unusual body odor. Although this does not appear to cause long-term sequelae, it may be misdiagnosed as maple syrup urine disease (9781,96068).
LACTATION: POSSIBLY SAFE
when used orally to stimulate lactation, short-term.
Although most available clinical studies lack safety testing in the lactating parent or infant (12535,22569,22570), some evidence suggests that taking fenugreek 1725 mg three times daily orally for 21 days does not cause negative side effects in the infant (90115).
POSSIBLY SAFE ...when used orally and appropriately, alone or in combination with probiotics, in doses up to 30 grams daily for up to 4 weeks (741,745,8505,90266,107729,107931). ...when a specific FOS product (NutraFlora, Ingredion Inc.) is used orally in combination with calcium at doses up to 3.2 grams daily for up to 24 months (94931).
CHILDREN: POSSIBLY SAFE
when short-chain FOS are included in approved infant formulas for healthy term infants at a level of up to 4 grams/L or 1 gram/kg daily (94929,94930,98651).
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
LIKELY SAFE ...when used orally in amounts commonly found in foods. Grapefruit has Generally Recognized as Safe status (GRAS) in the US (4912).
POSSIBLY SAFE ...when used orally and appropriately for medicinal purposes. A grapefruit seed extract has been safely used in clinical research (5866). In addition, capsules containing grapefruit pectin 15 grams daily have been used in clinical research for up to 16 weeks (2216).
POSSIBLY UNSAFE ...when used orally in excessive amounts. Preliminary population research shows that consuming a quarter or more of a whole grapefruit daily is associated with a 25% to 30% increased risk of postmenopausal breast cancer (14858). Grapefruit juice is thought to reduce estrogen metabolism resulting in increased endogenous estrogen levels. More evidence is needed to validate this finding.
PREGNANCY AND LACTATION:
There is insufficient reliable information available about the safety of using medicinal amounts of grapefruit during pregnancy and lactation; avoid using.
LIKELY SAFE ...when used orally and appropriately. A specific milk thistle extract standardized to contain 70% to 80% silymarin (Legalon, Madaus GmbH) has been safely used in doses up to 420 mg daily for up to 4 years (2613,2614,2616,7355,63210,63212,63278,63280,63299,63340)(88154,97626,105792). Higher doses of up to 2100 mg daily have been safely used for up to 48 weeks (63251,96107,101150). Another specific milk thistle extract of silymarin (Livergol, Goldaru Pharmaceutical Company) has been safely used at doses up to 420 mg daily for up to 6 months (95021,95029,102851,102852,105793,105794,105795,113979,114909,114913)(114914). Some isolated milk thistle constituents also appear to be safe. Silibinin (Siliphos, Thorne Research) has been used safely in doses up to 320 mg daily for 28 days (63218). Some combination products containing milk thistle and other ingredients also appear to be safe. A silybin-phosphatidylcholine complex (Silipide, Inverni della Beffa Research and Development Laboratories) has been safely used in doses of 480 mg daily for 7 days (7356) and 240 mg daily for 3 months (63320). Tree turmeric and milk thistle capsules (Berberol, PharmExtracta) standardized to contain 60% to 80% silybin have been safely used twice daily for up to 12 months (95019,96140,96141,96142,97624,101158).
POSSIBLY SAFE ...when used topically and appropriately, short-term. A milk thistle extract cream standardized to silymarin 0.25% (Leviaderm, Madaus GmbH) has been used safely throughout a course of radiotherapy (63239). Another milk thistle extract cream containing silymarin 1.4% has been used with apparent safety twice daily for 3 months (105791,110489). A cream containing milk thistle fruit extract 25% has been used with apparent safety twice daily for up to 12 weeks (111175). A milk thistle extract gel containing silymarin 1% has been used with apparent safety twice daily for 9 weeks (95022). There is insufficient reliable information available about the safety of intravenous formulations of milk thistle or its constituents.
PREGNANCY AND LACTATION:
While research in an animal model shows that taking milk thistle during pregnancy and lactation does not adversely impact infant development (102850), there is insufficient reliable information available about its safety during pregnancy or lactation in humans; avoid using.
CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term.
A milk thistle extract 140 mg three times daily has been used with apparent safety for up to 9 months (88154,98452). A specific product containing the milk thistle constituent silybin (Siliphos, Thorne Research Inc.) has been used with apparent safety in doses up to 320 mg daily for up to 4 weeks in children one year of age and older (63218).
LIKELY SAFE ...when used in amounts commonly found in foods.
POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts. Spinach has been used with apparent safety at a dose of 5 grams daily for up to 12 weeks (96856).
CHILDREN: LIKELY SAFE
when consumed in the amounts commonly found in foods by children older than 4 months of age (18).
CHILDREN: LIKELY UNSAFE
when used orally in infants under 4 months old; the high nitrate content of spinach can cause methemoglobinemia (18).
There is insufficient reliable information available about the safety of spinach in children when used in medicinal amounts.
PREGNANCY AND LACTATION: LIKELY SAFE
when used in amounts commonly found in foods; avoid medicinal amounts.
LIKELY SAFE ...when the ripe or unripe tomato fruit or its products are consumed in amounts found in foods (2406,9439,10418,106653,106654). ...when tomato leaf is consumed in regular food amounts (18).
POSSIBLY SAFE ...when a tomato extract is used orally for medicinal purposes. A specific tomato extract (Lyc-O-Mato, LycoRed Ltd) has been used with apparent safety in clinical studies lasting up to 8 weeks (7898,14287,102182).
POSSIBLY UNSAFE ...when the tomato leaf or unripe green tomato fruit is used orally in excessive amounts. Tomato leaf and unripe green tomatoes contain tomatine, which has been associated with toxicity when consumed in large quantities (18,102957). There is insufficient reliable information available about the safety of the tomato vine.
PREGNANCY AND LACTATION: LIKELY SAFE
when the tomato fruit or its products are consumed in typical food amounts.
There is insufficient reliable information available about the safety of tomato extracts when used during pregnancy or lactation; avoid using.
LIKELY SAFE ...when consumed in amounts commonly found in foods (5286).
POSSIBLY SAFE ...when wheatgrass juice is taken orally and appropriately in medicinal amounts. Wheatgrass juice 60-100 mL daily has been used safely for up to 18 months (11165,85601,104878,104879). ...when wheatgrass cream is used topically. Wheatgrass 10% cream has been used safely for up to 6 weeks (85602). There is insufficient reliable information available about the long-term safety of wheatgrass when used medicinally.
PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.
Below is general information about the interactions of the known ingredients contained in the product P2H. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
Theoretically, barley might decrease the clinical effects of triclabendazole.
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Animal research suggests that a diet supplemented with barley can reduce the bioavailability of triclabendazole when taken concomitantly (23884). This effect has not been shown in humans.
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Theoretically, celery juice might increase the effects and side effects of acetaminophen.
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Animal research suggests that concomitant use of celery juice plus acetaminophen prolongs the effects of acetaminophen. This effect has been attributed to a decrease in hepatic cytochrome P450 activity (25362). However, other animal research shows that pretreatment with celery root extract protects against acetaminophen-induced acute liver failure (106487). These effects have not been reported in humans.
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Theoretically, celery juice might increase the effects and side effects of aminopyrine.
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Animal research suggests that concomitant use of celery juice plus aminopyrine prolongs the effects of aminopyrine. This effect has been attributed to a decrease in hepatic cytochrome P450 activity (25362). This effect has not been reported in humans.
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Theoretically, celery root might increase the risk of bleeding when taken with anticoagulant/antiplatelet drugs.
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Theoretically, celery seed extract might have additive effects with antihypertensive drugs.
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Clinical research suggests that taking celery seed extract may reduce daytime systolic blood pressure by about 12 mmHg compared to less than 1 mmHg with placebo (110755).
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Theoretically, celery might increase levels of drugs metabolized by CYP1A2.
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In vitro and animal research suggests that constituents of celery can inhibit CYP1A2 (68176). This effect has not been reported in humans.
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Theoretically, celery seed might decrease the effects of levothyroxine.
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Several cases of hypothyroidism with low T4 levels have been reported in people who were previously stabilized on levothyroxine and then started taking celery seed tablets. They presented with symptoms such as lethargy, bloating, and dry skin, and recovered when celery seed was stopped (10646). However, celery stem and leaf has been associated with case reports of hyperthyroidism in patients with no pre-existing thyroid disorders (102912,102914).
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Theoretically, celery might reduce excretion and increase levels of lithium due to potential diuretic effects.
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Theoretically, celery might increase the risk of photosensitivity reactions when taken with photosensitizing drugs.
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Theoretically, celery root extract might increase blood levels of venlafaxine.
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There is one case report of a patient who experienced medication-induced bipolar disorder after beginning to take celery root extract 1000 mg daily along with venlafaxine 75 mg and St. John's wort 600 mg daily. Symptoms included confusion, speech abnormalities, manic affect, and visual hallucinations. The plasma level of venlafaxine was 476.8 ng/mL (normal range 195-400 ng/mL). It is theorized that celery root increased venlafaxine levels by inhibiting cytochrome P450 2D6 (92854).
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Theoretically, chlorella might have additive effects with photosensitizing drugs.
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Chlorella has been reported to cause photosensitization (3900,5852). In five case reports, patients who had ingested chlorella exhibited swelling followed by erythematopurpuric lesions on sun-exposed areas of the body (5852). Theoretically, concomitant use with photosensitizing drugs may exacerbate effects.
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Theoretically, chlorella might reduce the clinical effects of warfarin.
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Theoretically, taking dandelion root along with anticoagulant or antiplatelet drugs might increase the risk of bruising and bleeding.
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In vitro research suggests that dandelion root inhibits platelet aggregation (18291).
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Theoretically, dandelion might increase the risk for hypoglycemia when used with antidiabetes drugs.
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Laboratory research suggests that dandelion extract may have moderate alpha-glucosidase inhibitor activity and might also increase insulin secretion (13474,90926). Also, in a case report, a 58-year-old woman with type 2 diabetes who was being treated with insulin developed hypoglycemia 2 weeks after beginning to eat salads containing dandelion (46960).
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Theoretically, dandelion might increase levels of drugs metabolized by CYP1A2.
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Laboratory research suggests that dandelion might inhibit CYP1A2 (12734). So far, this interaction has not been reported in humans. However, until more is known, watch for an increase in the levels of drugs metabolized by CYP1A2 in patients taking dandelion.
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Theoretically, dandelion might increase the clearance of drugs that are UDP-glucuronosyltransferase substrates.
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There is some preliminary evidence that dandelion might induce UDP-glucuronosyltransferase, a phase II enzyme (12734).
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Theoretically, through diuretic effects, dandelion might reduce excretion and increase levels of lithium.
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Animal research suggests that dandelion has diuretic properties (13475). As diuretics can increase serum lithium levels, the dose of lithium might need to be decreased when taken with dandelion.
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Theoretically, dandelion might increase the risk of hyperkalemia when taken with potassium-sparing diuretics.
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Dandelion contains significant amounts of potassium (13465).
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Theoretically, dandelion might lower fluoroquinolone levels.
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Animal research shows that dandelion reduces absorption of ciprofloxacin and can lower levels by 73% (13477). However, this effect has not been reported in humans.
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Theoretically, fenugreek might have additive effects when used with anticoagulant or antiplatelet drugs.
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Some of the constituents in fenugreek have antiplatelet effects in animal and in vitro research. However, common fenugreek products might not contain sufficient concentrations of these constituents for clinical effects. A clinical study in patients with coronary artery disease or diabetes shows that taking fenugreek seed powder 2.5 grams twice daily for 3 months does not affect platelet aggregation, fibrinolytic activity, or fibrinogen levels (5191,7389,49643).
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Theoretically, fenugreek seed might have additive hypoglycemic effects when used with antidiabetes drugs.
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Theoretically, fenugreek seed might alter the clinical effects of clopidogrel by inhibiting its conversion to the active form.
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Animal research shows that fenugreek seed 200 mg/kg daily for 14 days increases the maximum serum concentration of clopidogrel by 21%. It is unclear how this affects the pharmacokinetics of the active metabolite of clopidogrel; however, this study found that concomitant use of fenugreek seed and clopidogrel prolonged bleeding time by an additional 11% (108701).
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Theoretically, fenugreek seed might have additive hypotensive effects when used with metoprolol.
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Animal research shows that fenugreek seed 300 mg/kg daily for 2 weeks decreases systolic and diastolic blood pressure by 9% and 11%, respectively, when administered alone, and by 15% and 22%, respectively, when given with metoprolol 10 mg/kg (108703).
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Theoretically, fenugreek might decrease plasma levels of phenytoin.
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Animal research shows that taking fenugreek seeds for 1 week decreases maximum concentrations and the area under the curve of a single dose of phenytoin by 44% and 72%, respectively. This seems to be related to increased clearance (110905). So far, this interaction has not been reported in humans.
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Theoretically, concurrent use of sildenafil and fenugreek might reduce levels and therapeutic effects of sildenafil.
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Animal research shows that taking fenugreek seeds for 1 week reduces maximum concentrations and the area under the curve of a single dose of sildenafil by 27% and 48%, respectively (110898). So far, this interaction has not been reported in humans.
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Theoretically, fenugreek may reduce the levels and clinical effects of theophylline.
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Animal research shows that fenugreek 50 grams daily for 7 days reduces the maximum serum concentration (Cmax) of theophylline by 28% and the area under the plasma drug concentration-time curve (AUC) by 22% (90118).
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Theoretically, fenugreek might have additive effects with warfarin and increase the international normalized ratio (INR).
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Grapefruit juice can decrease blood levels of acebutolol, potentially decreasing the clinical effects of acebutolol.
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Clinical research shows that grapefruit juice can modestly decrease acebutolol levels by 7% and reduce peak plasma concentration by 19% by inhibiting organic anion transporting polypeptide (OATP) (17603,18101). The acebutolol half-life is also extended by 1.1 hours when grapefruit juice is consumed concomitantly (18101). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604).
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Grapefruit juice can decrease blood levels of aliskiren, potentially decreasing the clinical effects of aliskiren.
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Clinical research shows that grapefruit juice can decrease aliskiren levels by approximately 60% by inhibiting organic anion transporting polypeptide (OATP) (91428). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604).
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Grapefruit juice can increase blood levels of amiodarone, potentially increasing the effects and adverse effects of amiodarone.
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Grapefruit juice might decrease blood levels of amprenavir, although this is not likely to be clinically significant.
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Some clinical research shows that grapefruit juice can slightly decrease amprenavir levels (17673); however, this is probably not clinically significant.
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Grapefruit juice can increase blood levels of oral artemether, potentially increasing the effects and adverse effects of artemether.
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Grapefruit juice might increase blood levels of some oral benzodiazepines, potentially increasing the effects and adverse effects of these drugs.
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Clinical research shows that grapefruit juice can increase plasma triazolam concentrations. Repeated consumption of grapefruit juice greatly increases triazolam concentrations and prolongs the half-life, probably due to inhibition of cytochrome P450 3A4 (CYP3A4) (7776,22118,22131,22133). Some studies show that grapefruit juice, particularly when taken in large quantities, reduces the clearance and increases the maximum blood levels, area under the plasma concentration curve (AUC), and duration of effect of midazolam. However, there is no effect on intravenous midazolam (4300,10159,11275,17601,22117,22119,16711,91427,95978). Grapefruit juice has also been shown to increase the maximum blood levels and duration of effect of diazepam, but the clinical significance of this is not known (3228). This interaction does not appear to occur with alprazolam (17674).
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Grapefruit juice can increase blood levels of blonanserin, potentially increasing the effects and adverse effects of blonanserin.
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Blonanserin is metabolized primarily by cytochrome P450 3A4 (CYP3A4). A small clinical study shows that taking grapefruit juice along with oral blonanserin increases exposure to blonanserin almost 6-fold due to inhibition of intestinal CYP3A4 by grapefruit juice and prolongs the elimination half-life of blonanserin by 2.2-fold due to inhibition of hepatic CYP3A4 by grapefruit juice (96943).
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Grapefruit juice can increase blood levels of budesonide, potentially increasing the effects and adverse effects of budesonide.
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Budesonide is metabolized by cytochrome P450 3A4 (CYP3A4). A small clinical study shows that taking grapefruit juice along with oral budesonide increases the plasma concentration of budesonide. This effect is attributed to grapefruit-induced inhibition of CYP3A4 in both the colon and small intestine (91425).
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Grapefruit juice can increase blood levels of buspirone, potentially increasing the effects and adverse effects of buspirone.
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Clinical research shows that grapefruit juice increases absorption and plasma concentrations of buspirone (3771).
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Grapefruit juice can decrease the clearance of caffeine, potentially increasing the effects and adverse effects of caffeine.
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Clinical research shows that grapefruit juice decreases caffeine clearance (4300).
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Grapefruit juice can increase blood levels of oral calcium channel blockers, potentially increasing the effects and adverse effects of these drugs.
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Clinical research shows that grapefruit juice increases absorption and plasma concentrations of amlodipine (523), nifedipine (528,22114), nisoldipine (529), verapamil (7779,8285), felodipine, nimodipine, nicardipine, diltiazem, pranidipine, nitrendipine, and manidipine (524,528,1388,4300,7780,11276,22136,53338,22138,22139) (22140,22141,22142,22143,22147,22148,22149,53367,22158),
This interaction is likely the result of the inhibition of intestinal metabolism of these drugs by CYP3A4 (7779,7780), although some research suggests grapefruit may alter plasma drug levels by reducing the rate of gastric emptying (22167). Consuming grapefruit juice 1 liter daily increases steady state concentrations of verapamil by as much as 50% (8285). However, some references dispute the clinical relevance of the interactions with amlodipine, diltiazem, and verapamil (3230,4300,22159). Other research in healthy individuals suggests plasma levels of felodipine and nifedipine are not affected when given intravenously (22144,22146). There is considerable interindividual variability in the effect of grapefruit juice on drug metabolism, which might account for inconsistent study results (7777,7779,8285). In healthy older adults, the hemodynamic response to felodipine plus grapefruit juice might be influenced by altered autonomic regulation. In older healthy adults, a single dose of grapefruit juice and felodipine enhanced the blood pressure-lowering effects of felodipine. However, after a week of grapefruit juice and felodipine (steady state), the hypotensive activity was reduced, possibly due to compensatory tachycardia (1392). Research indicates it is necessary to withhold grapefruit juice for as long as 3 days to avoid interactions with felodipine and nisoldipine (5068,5069,6453,22145).
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Grapefruit juice can increase blood levels of carbamazepine, potentially increasing the effects and adverse effects of carbamazepine.
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Clinical research shows that grapefruit juice increases absorption and plasma concentrations of carbamazepine (524).
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Grapefruit juice can increase blood levels of carvedilol, potentially increasing the effects and adverse effects of carvedilol.
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Clinical research shows that grapefruit juice increases the bioavailability of a single dose of carvedilol by 16% (5071).
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Grapefruit juice can decrease blood levels of celiprolol, potentially decreasing the clinical effects of celiprolol.
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In human research, taking grapefruit juice within two hours of celiprolol appears to decrease absorption and blood levels of celiprolol by approximately 85% (91421). This interaction is due to grapefruit-induced inhibition of organic anion transporting polypeptide (OATP) (17603,17604,22161). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604).
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Grapefruit juice can increase blood levels of cisapride, potentially increasing the effects and adverse effects of cisapride.
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Theoretically, grapefruit juice might increase blood levels of clomipramine, potentially increasing the effects and adverse effects of clomipramine.
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Case reports have shown that clomipramine trough levels increase significantly after the addition of grapefruit juice to the therapeutic regimen (5064).
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Grapefruit juice can decrease blood levels of the active metabolite of clopidogrel, thereby decreasing the antiplatelet effect of clopidogrel.
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Clopidogrel is an antiplatelet prodrug that is metabolized primarily by cytochrome P450 2C19 (CYP2C19) to form the active metabolite. A small clinical study shows that taking grapefruit juice with clopidogrel decreases plasma levels of the active metabolite by more than 80% and impairs the antiplatelet effect of clopidogrel. This effect is possibly due to grapefruit-induced inhibition of CYP2C19 (91419).
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Theoretically, grapefruit juice might increase blood levels of colchicine, potentially increasing the effects and adverse effects of colchicine.
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Colchicine is an alkaloid that undergoes P-glycoprotein (P-gp) mediated drug efflux in the intestines, followed by metabolism by cytochrome P450 3A4 (CYP3A4). There is concern that grapefruit juice will increase the effects and adverse effects of colchicine due to grapefruit-induced inhibition of P-gp and/or CYP3A4. In vitro evidence shows that grapefruit juice increases absorption of colchicine by inhibiting P-gp (94158). A case of acute colchicine toxicity has been reported for an 8-year-old female who drank grapefruit juice while taking high-dose colchicine, long-term (94157). However, one small clinical study in healthy adults shows that drinking grapefruit juice 240 mL twice daily for 4 days does not affect the bioavailability or adverse effects of a single dose of colchicine 0.6 mg taken on the fourth day (35762).
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Grapefruit juice can increase blood levels of oral cyclosporine, potentially increasing the effects and adverse effects of cyclosporine.
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Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP1A2.
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In vitro research suggests that grapefruit juice might inhibit CYP1A2 enzymes (12479). So far, this interaction has not been reported in humans.
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Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP2C19.
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In vitro research suggests that grapefruit juice might inhibit CYP2C19 enzymes (12479). Also, a small clinical study shows that taking grapefruit juice with clopidogrel, an antiplatelet prodrug that is metabolized primarily by CYP2C19, decreases plasma levels of the active metabolite and impairs the antiplatelet effect of clopidogrel. This effect is likely due to grapefruit-induced inhibition of CYP2C19 (91419).
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Theoretically, grapefruit juice might increase levels of drugs metabolized by CYP2C9.
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In vitro research suggests that grapefruit juice might inhibit CYP2C9 enzymes (12479). So far, this interaction has not been reported in humans.
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Grapefruit juice can increase levels of drugs metabolized by CYP3A4.
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Clinical research shows that grapefruit juice can inhibit CYP3A4 metabolism of drugs, causing increased drug levels and potentially increasing the risk of adverse effects (3227,3774,8283,8285,8286,22129,91427,104190). When taken orally, effects of grapefruit juice on CYP3A4 levels appear to last at least 48 hours (91427). Grapefruit's ability to inhibit CYP3A4 has even been harnessed to intentionally increase levels of venetoclax, which is metabolized by CYP3A4, in an elderly patient with acute myeloid leukemia who could not afford full dose venetoclax. The lower dose of venetoclax in combination with grapefruit juice resulted in serum levels of venetoclax in the therapeutic reference range of full dose venetoclax and positive treatment outcomes for the patient (112287).
Professional consensus recommends the consideration of patient age, existing medical conditions, additional medications, and the potential for additive adverse effects when evaluating the risks of concomitant use of grapefruit juice with any medication metabolized by CYP3A4. While all patients are at risk for interactions with grapefruit juice consumption, patients older than 70 years of age and those taking multiple medications are at the greatest risk for a serious or fatal interaction with grapefruit juice (95970,95972). |
Grapefruit juice can increase blood levels of dapoxetine, potentially increasing the effects and adverse effects of dapoxetine.
Details
Pharmacokinetic research shows that drinking grapefruit juice 250 mL prior to taking dapoxetine 60 mg can increase the maximum plasma concentration of dapoxetine by 80% and prolong the elimination half-life by 43%. This effect is attributed to the inhibition of both intestinal and hepatic cytochrome P450 3A4 (CYP3A4) by grapefruit (95975).
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Grapefruit juice can increase blood levels of dextromethorphan, potentially increasing the effects and adverse effects of dextromethorphan.
Details
Clinical research shows that grapefruit juice can inhibit cytochrome P450 3A4 (CYP3A4) metabolism, causing increased dextromethorphan levels (11362).
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Theoretically, grapefruit juice may increase the levels and clinical effects of empagliflozin.
Details
Animal research suggests grapefruit juice increases the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of empagliflozin, possibly due to inhibition of metabolism by uridine diphosphoglucuronosyl transferase (UGT) (115467). This effect has not been reported in humans.
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Grapefruit juice can increase blood levels of erythromycin, potentially increasing the effects and adverse effects of erythromycin.
Details
Clinical research shows that concomitant use of erythromycin with grapefruit can inhibit cytochrome P450 3A4 (CYP3A4) metabolism of erythromycin, increasing plasma concentrations of erythromycin by 35% (8286).
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Grapefruit juice can increase blood levels of estrogens, potentially increasing the effects and adverse effects of estrogens.
Details
Clinical research shows that grapefruit increases the levels of endogenous and exogenous estrogens by inhibiting cytochrome P450 3A4 (CYP3A4) enzymes (525,526,14858). Grapefruit juice increases exogenously administered 17-beta-estradiol by about 20% in females without ovaries and ethinyl-estradiol in healthy females (525,526,22160).
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Grapefruit juice can decrease blood levels of etoposide, potentially decreasing the clinical effects of etoposide.
Details
Clinical research shows that grapefruit juice decreases the absorption and plasma concentrations of etoposide. There is some evidence that grapefruit juice co-administered with oral etoposide can reduce levels of etoposide by about 26% (8744). Grapefruit juice seems to inhibit organic anion transporting polypeptide (OATP), which is a drug transporter in the gut, liver, and kidney (7046,17603,17604). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604).
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Grapefruit juice can decrease blood levels of fexofenadine, thereby decreasing the clinical effects of fexofenadine.
Details
Clinical research shows that grapefruit juice can significantly decrease oral absorption and blood levels of fexofenadine. In one study, consuming a drink containing grapefruit juice 25% decreased bioavailability of fexofenadine by about 24%. Consuming a full-strength grapefruit juice drink reduced bioavailability by 67% (7046). In another study, consuming grapefruit juice 300 mL decreased fexofenadine levels by 42%. Consuming 1200 mL of grapefruit juice reduced levels by 64% (17602). Similarly, drinking grapefruit juice 240 mL decreased the oral bioavailability of fexofenadine by 25% in another pharmacokinetic study (112288). Fexofenadine manufacturer data indicates that concomitant administration of grapefruit juice and fexofenadine results in larger wheal and flare sizes in research models. This suggests that grapefruit also reduces the clinical response to fexofenadine (17603).
Grapefruit juice seems to inhibit organic anion transporting polypeptide (OATP), which is a drug transporter in the gut, liver, and kidney (7046,17603,17604,22161). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604). |
Grapefruit juice can increase blood levels of fluvoxamine, potentially increasing the effects and adverse effects of fluvoxamine.
Details
Clinical research shows that grapefruit juice inhibits metabolism and increases fluvoxamine levels and peak concentration (17675).
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Grapefruit juice can increase blood levels of halofantrine, potentially increasing the effects and adverse effects of halofantrine.
Details
Clinical research shows that grapefruit juice inhibits cytochrome P450 3A4 (CYP3A4) metabolism, which increases halofantrine levels and peak concentration, as well as a marker of ventricular tachyarrhythmia potential (22129).
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Grapefruit juice can increase blood levels of statins that are metabolized by cytochrome P450 3A4 (CYP3A4), potentially increasing the effects and adverse effects of these statins. Additionally, grapefruit juice might interfere with the bioavailability of statins that are substrates of organic anion transporting polypeptides (OATP).
Details
Clinical research shows that grapefruit juice inhibits metabolism and increases absorption and plasma concentrations of statins that are metabolized by CYP3A4. These include lovastatin (527,11274), simvastatin (3774,7782,22127), and atorvastatin (3227,12179,22126). Keep in mind that there is considerable variability in the effect of grapefruit juice on drug metabolism, so individual patient response is difficult to predict (7777,7781).
Some statins, including pravastatin, fluvastatin, pitavastatin, and rosuvastatin, are not metabolized by CYP3A4. However, grapefruit juice might still affect the bioavailability of these statins. These statins are substrates of OATP. Grapefruit juice can inhibit OATP. Therefore, grapefruit juice may reduce the bioavailability or increase drug levels of these statins depending on the type of OATP. However, grapefruit juice affects OATP for only a short time. Therefore, separating drug administration by at least 4 hours is likely to avoid this interaction (3227,12179,17601,22126,91420). |
Grapefruit juice can interfere with itraconazole absorption, although the clinical significance of this interaction is unclear.
Details
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Grapefruit juice can decrease blood levels of levothyroxine, potentially decreasing the effectiveness of levothyroxine.
Details
Clinical research shows that grapefruit juice modestly decreases levothyroxine levels by 11% by inhibiting organic anion transporting polypeptide (OATP) (17604,22163). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604).
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Grapefruit juice can decrease blood levels of the active metabolite of losartan, potentially decreasing the clinical effects of losartan.
Details
Losartan is an inactive prodrug which must be metabolized to its active form, E-3174, to be effective. In one human study, grapefruit juice reduced losartan metabolism, increased losartan AUC, and reduced the AUC of the major active losartan metabolite, E-3174 (1391).
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Grapefruit juice can increase blood levels of methadone, potentially increasing the effects and adverse effects of methadone.
Details
Clinical research shows that grapefruit juice inhibits the metabolism of methadone, increasing methadone levels and peak concentrations (17676). In one case, a 51-year-old male taking methadone 90 mg daily and no other medications was found unresponsive. The patient reported drinking grapefruit juice 500 mL daily for 3 days prior to the event. Methadone is a substrate of cytochrome P450 3A4 (CYP3A4), and grapefruit juice-induced inhibition of CYP3A4 is the likely cause of this interaction (102056).
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Grapefruit juice can increase blood levels of methylprednisolone, potentially increasing the effects and adverse effects of methylprednisolone.
Details
Clinical research shows that grapefruit juice can increase the plasma concentration of orally administered methylprednisolone. Grapefruit juice 200 mL three times daily given with methylprednisolone 16 mg increased methylprednisolone half-life by 35%, peak plasma concentration by 27%, and total area under the curve by 75% (3123).
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Grapefruit juice might decrease blood levels of nadolol, potentially decreasing the clinical effects of nadolol.
Details
Nadolol is a substrate of organic anion transporting polypeptide 1A2 (OATP1A2) (17603,17604,22161). Some research shows that grapefruit juice and its constituent naringin can inhibit organic anion transporting polypeptides (OATP), which can reduce the bioavailability of OATP substrates (17603,17604,22161,91427). However, preliminary clinical research shows that grapefruit juice containing a low amount of naringin does not significantly affect levels of nadolol (91422). It is not known if grapefruit juice containing higher amounts of naringin reduces the bioavailability of nadolol.
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Grapefruit juice can increase blood levels of nilotinib, potentially increasing the effects and adverse effects of nilotinib.
Details
Clinical research shows that grapefruit juice inhibits metabolism and increases absorption of nilotinib. Grapefruit juice increases nilotinib levels by 29% and peak concentration by 60% (17677).
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Grapefruit juice can decrease levels of drugs that are substrates of OATP.
Details
In vitro and clinical research show that consuming grapefruit juice inhibits OATP, which reduces the bioavailability of oral drugs that are substrates of OATP. Various clinical studies have shown reduced absorption of OATP substrates when taken with grapefruit, including fexofenadine, acebutolol, aliskiren, celiprolol, levothyroxine, nadolol, and pitavastatin (17603,17604,18101,22126,22134,22161,22163,91420,91427,91428,112288). Grapefruit juice is thought to affect OATP for only a short time. Therefore, separating drug administration and consumption of grapefruit by at least 4 hours is likely to prevent this interaction (17603,17604).
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Grapefruit juice can increase blood levels of oxycodone, potentially increasing the effects and adverse effects of oxycodone.
Details
Oxycodone is metabolized by both cytochrome P450 3A4 (CYP3A4) and cytochrome P450 2D6 (CYP2D6). A small clinical study shows that grapefruit juice can increase plasma levels of oral oxycodone about 1.7-fold by inhibiting CYP3A4. While the analgesic effects of oxycodone do not seem to be affected, taking grapefruit juice along with oxycodone may theoretically increase the adverse effects of oxycodone (91423).
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Grapefruit juice does not seem to affect renal P-glycoprotein (P-gp). Theoretically, it might inhibit intestinal P-gp, but evidence is conflicting.
Details
While most in vitro research shows that grapefruit products inhibit P-gp, (1390,11270,11278,11362,95976), research in humans is less clear. Two small clinical studies in healthy adults using digoxin as a probe substrate show that grapefruit juice does not inhibit P-gp in the kidneys (11277,11282). It is unclear whether this applies to intestinal P-gp, for which digoxin is not considered to be a sensitive probe (105568). Grapefruit juice has been shown to reduce levels of fexofenadine (7046,17602,112288), and increase levels of quinidine (5067,22121). However, as both of these drugs are also substrates of other enzymes and transporters, it is unclear what role, if any, intestinal P-gp has in these findings.
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Grapefruit juice can increase blood levels of pitavastatin, potentially increasing the effects and adverse effects of pitavastatin.
Details
Pharmacokinetic research shows that taking grapefruit juice with pitavastatin 2-4 mg can increase blood levels of pitavastatin by 13% to 14%. Unlike simvastatin and atorvastatin, pitavastatin is not significantly metabolized by cytochrome P450 3A4 (CYP3A4) enzymes. Grapefruit juice appears to increase levels of pitavastatin by inhibiting its uptake by organic anion transporting polypeptide 1B1 (OATP1B1) into hepatocytes for metabolism and clearance from the body (22126,91420). Grapefruit juice seems to increase levels of pitavastatin to a greater degree in patients homozygous for a specific polymorphism (388A>G) in the OATP1B1 gene compared to those heterozygous for this polymorphism (91420).
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Grapefruit juice can decrease blood levels of the active metabolite of prasugrel, thereby decreasing the antiplatelet effect of prasugrel.
Details
Prasugrel is a prodrug that is metabolized by cytochrome P450 3A4 (CYP3A4) into its active metabolite. A small pharmacokinetic study in healthy volunteers shows that drinking grapefruit juice 200 mL three times daily for 4 days and taking a single dose of prasugrel 10 mg with an additional 200 mL of grapefruit juice on day 3, results in a 49% lower peak plasma level and a 26% lower overall plasma exposure to the active metabolite when compared with drinking water. However, despite the reduced exposure, platelet aggregation seems to be reduced by an average of only 5% (105567). The clinical significance of this interaction is unclear.
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Grapefruit juice can increase blood levels of praziquantel, potentially increasing the effects and adverse effects of praziquantel.
Details
Clinical research shows that grapefruit juice can inhibit cytochrome P450 3A4 (CYP3A4) metabolism of praziquantel. Plasma concentrations of praziquantel can increase by as much as 160% when administered with 250 mL of commercially available grapefruit juice (8282).
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Grapefruit juice may increase blood levels of primaquine, potentially increasing the effects and adverse effects of primaquine.
Details
Clinical research shows that grapefruit juice increases the bioavailability of primaquine by approximately 20% (22130). The clinical significance of this interaction is not clear.
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Grapefruit or grapefruit juice, especially if consumed in large amounts, can cause additive QT interval prolongation when taken with QT interval-prolonging drugs, potentially increasing the risk of ventricular arrhythmias.
Details
Clinical research in healthy volunteers shows that drinking 6 liters of grapefruit juice over 6 hours prolonged the QTc by a peak amount of 14 milliseconds (ms). This prolongation was similar to the QT prolongation caused by the drug moxifloxacin. In individuals with long QT syndrome, a smaller dose of grapefruit juice, 1.5 liters, resulted in a greater peak QTc prolongation of about 30 ms (100249). The effect of smaller quantities of grapefruit juice on the QT interval is unclear.
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Grapefruit juice may increase blood levels of quetiapine, increasing the effects and adverse effects of quetiapine.
Details
Quetiapine is metabolized by cytochrome P450 3A4 (CYP3A4). Grapefruit can inhibit CYP3A4 (3227,3774,8283,8285,8286,22129,91427,104190). In one case report, a healthy 28-year-old female with bipolar disorder stabilized on quetiapine 800 mg daily presented with quetiapine toxicity considered to be related to consuming a gallon of grapefruit juice over the past 24 hours (108848).
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Grapefruit juice can alter blood levels of quinidine, potentially increasing or decreasing the clinical effects of quinidine.
Details
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Theoretically, grapefruit juice may increase the concentration and clinical effects of rivaroxaban.
Details
Rivaroxaban is metabolized partially by cytochrome P450 3A4 (CYP3A4). Grapefruit juice can inhibit CYP3A4. Animal research shows that grapefruit juice increases the peak plasma concentration (Cmax) of rivaroxaban by about four-fold, without increasing the area under the drug concentration-time curve (AUC) (115468).
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Grapefruit juice can increase blood levels of saquinavir, potentially increasing the effects and adverse effects of saquinavir.
Details
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Grapefruit juice can increase blood levels of scopolamine, potentially increasing the effects and adverse effects of scopolamine.
Details
Clinical research shows that grapefruit juice can inhibit cytochrome P450 3A4 (CYP3A4) metabolism of scopolamine, increasing its absorption and plasma concentrations. Oral bioavailability of scopolamine can increase by 30% when administered with 150 mL of grapefruit juice (8284).
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Grapefruit juice can increase blood levels of sertraline, potentially increasing the effects and adverse effects of sertraline.
Details
Clinical research shows that grapefruit juice inhibits the cytochrome P450 3A4 (CYP3A4) metabolism of sertraline, increasing blood levels of sertraline (22122).
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Grapefruit juice can increase blood levels of sildenafil, potentially increasing the effects and adverse effects of sildenafil.
Details
Clinical research shows that grapefruit juice inhibits cytochrome P450 3A4 (CYP3A4) metabolism of sildenafil, increasing its absorption and plasma concentrations. Oral bioavailability of sildenafil can increase by 23% when administered with 500 mL of commercially available grapefruit juice (8283).
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Grapefruit juice may slightly increase blood levels of sunitinib, potentially increasing the effects and adverse effects of sunitinib.
Details
Sunitinib is metabolized by cytochrome P450 3A4 (CYP3A4). Grapefruit and grapefruit juice can inhibit CYP3A4 and increase levels of some drugs metabolized by this enzyme. One small clinical study shows that drinking 200 mL of grapefruit juice three times daily can increase the bioavailability of sunitinib by 11% (91429). While this effect is unlikely to be clinically significant, patients should use caution when using grapefruit along with sunitinib. Dose adjustments may be necessary.
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Grapefruit juice can increase blood levels of tacrolimus, potentially increasing the effects and adverse effects of tacrolimus.
Details
Clinical research shows that drinking grapefruit juice 200 mL daily while taking tacrolimus 3 mg daily increases the trough blood concentration of tacrolimus by approximately 3-fold in patients with connective tissue diseases (95974). A single case has also reported a 10-fold increase in tacrolimus trough levels after the ingestion of grapefruit juice over 3 days (22122). This effect is attributed to the inhibition of cytochrome P450 3A4 (CYP3A4) by grapefruit (95974).
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Theoretically, grapefruit juice might increase blood levels of tadalafil, potentially increasing the effects and adverse effects of tadalafil.
Details
Animal research shows that grapefruit juice increases tadalafil serum concentrations and overall exposure, likely through inhibition of cytochrome P450 3A4 enzymes (104189).
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Grapefruit juice might decrease blood levels of talinolol, potentially decreasing the clinical effects of talinolol.
Details
Clinical research suggests that grapefruit juice reduces talinolol bioavailability, likely by inhibiting intestinal uptake (22135). The clinical significance of this effect is unclear.
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Grapefruit juice can increase blood levels of terfenadine, potentially increasing the effects and adverse effects of terfenadine.
Details
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Grapefruit juice can decrease blood levels of theophylline, potentially decreasing the effectiveness of theophylline.
Details
Clinical research shows that grapefruit juice seems to modestly decrease theophylline levels when given concurrently with sustained-release theophylline (11013). The mechanism of this interaction is unknown.
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Grapefruit juice can increase blood levels of ticagrelor, thereby increasing the effects and adverse effects of ticagrelor.
Details
Ticagrelor is metabolized by cytochrome P450 3A4 (CYP3A4). Grapefruit can inhibit CYP3A4. A small clinical study shows that taking grapefruit juice with ticagrelor increases blood levels of ticagrelor more than two-fold and increases the antiplatelet activity of ticagrelor (91418). Additionally, animal research shows that grapefruit juice increases peak plasma concentration (Cmax) and the area under the drug concentration-time curve (AUC) of ticagrelor (115468).
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Grapefruit juice can increase blood levels of tolvaptan, potentially increasing the effects and adverse effects of tolvaptan.
Details
Tolvaptan is metabolized by cytochrome P450 3A4 (CYP3A4). Grapefruit can inhibit CYP3A4. A small clinical study shows that grapefruit juice can increase the bioavailability and blood levels of tolvaptan by approximately 1.6-fold for up to 16 hours (91426).
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Theoretically, drinking large amounts of grapefruit juice might increase the effects and adverse effects of warfarin.
Details
In one case report, a patient experienced significantly increased international normalized ratio (INR) associated with consumption of 50 ounces of grapefruit juice daily (12061). However, smaller amounts of grapefruit juice might not be a problem. In a small clinical trial, consumption of 24 ounces of grapefruit juice daily for one week had no effect on INR in males treated with warfarin (12063).
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Taking milk thistle with antidiabetes drugs may increase the risk of hypoglycemia.
Details
Clinical research shows that milk thistle extract, alone or along with tree turmeric extract, can lower blood glucose levels and glycated hemoglobin (HbA1c) in patients with type 2 diabetes, including those already taking antidiabetes drugs (15102,63190,63314,63318,95019,96140,96141,97624,97626,113987). Additionally, animal research shows that milk thistle extract increases the metformin maximum plasma concentration and area under the curve and decreases the renal clearance of metformin, due to inhibition of the multi-drug and toxin extrusion protein 1 (MATE1) renal tubular transport protein (114919).
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Theoretically, milk thistle might inhibit CYP2B6.
Details
An in vitro study shows that silybin, a constituent of milk thistle, binds to and noncompetitively inhibits CYP2B6. Additionally, silybin might downregulate the expression of CYP2B6 by decreasing mRNA and protein levels (112229).
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It is unclear if milk thistle inhibits CYP2C9; research is conflicting.
Details
In vitro research suggests that milk thistle might inhibit CYP2C9 (7089,17973,17976). Additionally, 3 case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking milk thistle and cancer medications that are CYP2C9 substrates, including imatinib and capecitabine (111644). However, contradictory clinical research shows that milk thistle extract does not inhibit CYP2C9 or significantly affect levels of the CYP2C9 substrate tolbutamide (13712,95026). Differences in results could be due to differences in dosages or formulations utilized (95026).
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It is unclear if milk thistle inhibits CYP3A4; research is conflicting.
Details
While laboratory research shows conflicting results (7318,17973,17975,17976), pharmacokinetic research shows that taking milk thistle extract 420-1350 mg daily does not significantly affect the metabolism of the CYP3A4 substrates irinotecan, midazolam, or indinavir (8234,17974,93578,95026). However, 8 case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking milk thistle and cancer medications that are CYP3A4 substrates, including gefitinib, sorafenib, doxorubicin, and vincristine (111644).
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Theoretically, milk thistle might interfere with estrogen therapy through competition for estrogen receptors.
Details
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Theoretically, milk thistle might affect the clearance of drugs that undergo glucuronidation.
Details
Laboratory research shows that milk thistle constituents inhibit uridine diphosphoglucuronosyl transferase (UGT), the major phase 2 enzyme that is responsible for glucuronidation (7318,17973). Theoretically, this could decrease the clearance and increase levels of glucuronidated drugs. Other laboratory research suggests that a milk thistle extract of silymarin might inhibit beta-glucuronidase (7354), although the significance of this effect is unclear.
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Theoretically, milk thistle might interfere with statin therapy by decreasing the activity of organic anion transporting polypeptide 1B1 (OATB1B1) and inhibiting breast cancer resistance protein (BCRP).
Details
Preliminary evidence suggests that a milk thistle extract of silymarin can decrease the activity of the OATP1B1, which transports HMG-CoA reductase inhibitors into the liver to their site of action, and animal research shows this increases the maximum plasma concentration of pitavastatin and pravastatin (113975). The silibinin component also inhibits BCRP, which transports statins from the liver into the bile for excretion. However, in a preliminary study in healthy males, silymarin 140 mg three times daily had no effect on the pharmacokinetics of a single 10 mg dose of rosuvastatin (16408).
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Theoretically, milk thistle may induce cytochrome P450 3A4 (CYP3A4) enzymes and increase the metabolism of indinavir; however, results are conflicting.
Details
One pharmacokinetic study shows that taking milk thistle (Standardized Milk Thistle, General Nutrition Corp.) 175 mg three times daily in combination with multiple doses of indinavir 800 mg every 8 hours decreases the mean trough levels of indinavir by 25% (8234). However, results from the same pharmacokinetic study show that milk thistle does not affect the overall exposure to indinavir (8234). Furthermore, two other pharmacokinetic studies show that taking specific milk thistle extract (Legalon, Rottapharm Madaus; Thisilyn, Nature's Way) 160-450 mg every 8 hours in combination with multiple doses of indinavir 800 mg every 8 hours does not reduce levels of indinavir (93578).
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Theoretically, milk thistle might increase the levels and clinical effects of ledipasvir.
Details
Animal research in rats shows that milk thistle increases the area under the curve (AUC) for ledipasvir and slows its elimination (109505).
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Theoretically, concomitant use of milk thistle with morphine might affect serum levels of morphine and either increase or decrease its effects.
Details
Animal research shows that milk thistle reduces serum levels of morphine by up to 66% (101161). In contrast, laboratory research shows that milk thistle constituents inhibit uridine diphosphoglucuronosyl transferase (UGT), the major phase 2 enzyme that is responsible for glucuronidation (7318,17973). Theoretically, this could decrease the clearance and increase morphine levels. The effect of taking milk thistle on morphine metabolism in humans is not known.
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Milk thistle may inhibit one form of OATP, OATP-B1, which could reduce the bioavailability and clinical effects of OATP-B1 substrates.
Details
In vitro research shows that milk thistle inhibits OATP-B1. Two case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking milk thistle and cancer medications that are OATP substrates, including sorafenib and methotrexate (111644). OATPs are expressed in the small intestine and liver and are responsible for the uptake of drugs and other compounds into the body. Inhibition of OATP may reduce the bioavailability of oral drugs that are substrates of OATP.
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Theoretically, milk thistle might increase the absorption of P-glycoprotein substrates. However, this effect does not seem to be clinically significant.
Details
In vitro research shows that milk thistle can inhibit P-glycoprotein activity (95019,111644) and 1 case report from the World Health Organization (WHO) adverse drug reaction database describes increased abdominal pain in a patient taking milk thistle and the cancer medication vincristine, a P-glycoprotein substrate, though this patient was also taking methotrexate (111644). However, a small pharmacokinetic study in healthy volunteers shows that taking milk thistle (Enzymatic Therapy Inc.) 900 mg, standardized to 80% silymarin, in 3 divided doses daily for 14 days does not affect absorption of digoxin, a P-glycoprotein substrate (35825).
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Theoretically, milk thistle might decrease the clearance and increase levels of raloxifene.
Details
Laboratory research suggests that the milk thistle constituents silibinin and silymarin inhibit the glucuronidation of raloxifene in the intestines (93024).
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Milk thistle might decrease the clearance of sirolimus.
Details
Pharmacokinetic research shows that a milk thistle extract of silymarin decreases the apparent clearance of sirolimus in hepatically impaired renal transplant patients (19876). It is unclear if this interaction occurs in patients without hepatic impairment.
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Theoretically, milk thistle might decrease the levels and clinical effects of sofosbuvir.
Details
Animal research in rats shows that milk thistle reduces the metabolism of sofosbuvir, as well as the hepatic uptake of its active metabolite (109505).
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Theoretically, the milk thistle constituent silibinin might increase tamoxifen levels and interfere with its conversion to an active metabolite.
Details
Animal research suggests that the milk thistle constituent silibinin might increase plasma levels of tamoxifen and alter its conversion to an active metabolite. The mechanism appears to involve inhibition of pre-systemic metabolism of tamoxifen by cytochrome P450 (CYP) 2C9 and CYP3A4, and inhibition of P-glycoprotein-mediated efflux of tamoxifen into the intestine for excretion (17101). Whether this interaction occurs in humans is not known.
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Theoretically, milk thistle might increase the effects of warfarin.
Details
In one case report, a man stabilized on warfarin experienced an increase in INR from 2.64 to 4.12 after taking a combination product containing milk thistle 200 mg daily, as well as dandelion, wild yam, niacinamide, and vitamin B12. Levels returned to normal after stopping the supplement (101159). Although a direct correlation between milk thistle and the change in INR cannot be confirmed, some in vitro research suggests that milk thistle might inhibit cytochrome P450 2C9 (CYP2C9), an enzyme involved in the metabolism of various drugs, including warfarin (7089,17973,17976).
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Spinach contains vitamin K, which can interfere with the activity of warfarin.
Details
In human research, although eating spinach with one meal does not result in coagulation test results outside the therapeutic range, daily consumption for one week necessitates dose adjustment of warfarin (19600). Individuals using anticoagulants should consume a consistent daily amount of spinach to maintain the effect of anticoagulant therapy (19).
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Theoretically, taking wheatgrass with antidiabetes drugs might lower blood glucose levels and increase the risk of hypoglycemia.
Details
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Theoretically, wheatgrass might decrease the levels and clinical effects of CYP1A2 substrates.
Details
In vitro research shows that wheatgrass induces CYP1A2 enzymes (111404).
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Below is general information about the adverse effects of the known ingredients contained in the product P2H. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.
General
...Orally, barley is well tolerated.
Most Common Adverse Effects:
Orally: Abdominal distension, bloating, flatulence, unpleasant taste. Allergic reactions in sensitive individuals.
Topically: Allergic reactions in sensitive individuals.
Dermatologic ...Topically, barley malt contained in beer has been reported to cause contact dermatitis (33762). After occupational exposure, barley has been reported to cause contact dermatitis of the eyelids and extremities, as well as contact urticaria (33735,33770,33774).
Gastrointestinal
...When consumed orally, barley provides fiber.
Increasing fiber in the diet can cause flatulence, bloating, abdominal distention, and unpleasant taste. To minimize side effects, doses should be slowly titrated to the desired level. Adverse effects usually subside with continued use (12514).
Barley contains gluten. In patients with biopsy-proven celiac disease, consuming barley can cause gastrointestinal upset and impairment of xylose excretion (33763,33772).
Immunologic
...Orally, consumption of beer has been reported to cause allergic reactions in sensitive individuals (33722,33724).
Symptoms included tingling in the face, lip, and tongue, angioedema, generalized urticaria, chest tightness, dyspnea, cough, fainting, and rhinoconjunctivitis. It can also cause anaphylaxis in sensitive individuals (317). Topically and with occupational exposure, barley has been reported to cause contact dermatitis and rash (33762,33735,33770,33774).
"Bakers' asthma" is an allergic response resulting from the inhalation of cereal flours by workers in the baking and milling industries, and has been reported to occur after barley flour exposure (1300,33756,33760). Cross-allergenicity has been shown to exist between different cereals (33758).
Pulmonary/Respiratory
..."Bakers' asthma" is an allergic response resulting from the inhalation of cereal flours by workers in the baking and milling industries, and has been reported to occur after barley flour exposure (1300,33756,33760).
Cross-allergenicity has been shown to exist between different cereals (33758).
By inhalation, barley flours may be a source of allergens in asthma (33764,33773). Inhalation of wild barley grass pollen may result in bronchial irritation or pneumonitis (33726,33755).
General
...Orally, celery seems to be well tolerated.
Most Common Adverse Effects:
Orally: Photosensitivity. Oral allergy syndrome in sensitive individuals.
Topically: Photosensitivity. Contact dermatitis in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Anaphylaxis in sensitive individuals.
Dermatologic
...Due to its psoralen content, contact with or ingestion of celery and exposure to ultraviolet radiation may cause photodermatitis (4,34347,40968,40969,40986,41085,41087,41143,41146,41151).
Acute symptoms include skin eruption with edema and erythema; the main chronic symptom is hyperpigmentation at the eruption site (41093).
Celery can also cause contact or atopic dermatitis (19,41118,41124) and urticaria pigmentosa (40908).
Endocrine
...Celery has been associated with hyperthyroidism in otherwise healthy adults.
In one case report a 36-year-old female presented with weight loss, blurred vision, nausea, palpitations, sweating, exophthalmos, elevated serum T4 levels, and low thyroid stimulating hormone (TSH) levels after taking 8 grams of a powdered celery extract for 78 days (102912). In another case report, a 48-year-old male presented with weight loss, exophthalmos, sweating, elevated serum T4 levels, and low TSH levels after taking 4 grams of dried celery leaves for 45 days (102914). In both of these cases, symptoms resolved and thyroid function tests normalized after discontinuing celery and completing a course of methimazole.
In contrast, several cases of hypothyroidism with low T4 levels have been reported in people who were previously stabilized on levothyroxine and then started taking celery seed tablets. They presented with symptoms such as lethargy, bloating, and dry skin, and recovered when celery seed was stopped (10646).
Gastrointestinal ...Symptoms of celery allergy have included oral allergy syndrome, characterized by itching and burning in the mouth and throat (41159,40977,115301), and laryngeal edema (40953).
Immunologic
...Raw celery, cooked celery, and celery juice can all cause allergic reactions (40908,40926,41118,41131,92852,92855,115301).
Symptoms of celery allergy include laryngeal edema, skin reactions, nasal congestion and discharge, an urticaria-edema-anaphylactic shock syndrome, celery-dependent exercise-induced anaphylaxis, and anaphylactic shock (40953,41100,41102,41107,41115,41124,41129,41135,41137,92852)(92855,115301). Additionally, in clinical research, itchy throat has been reported in individuals taking celery seed powder (112410).
There is a case report of anaphylactic shock involving hypotension, tachycardia, and tachypnea in a patient who had ingested raw celery 15 minutes prior to symptom onset. The patient was treated with epinephrine, dexamethasone, and antazoline (92855). Another case report describes a patient with positive skin prick tests to celery, pollens including birch, chrysanthemum, mugwort, and ragweed, and to dust mites. When celery was consumed 30 minutes prior to exercise, the patient had an anaphylactic reaction that required treatment with intravenous pheniramine and corticosteroid, as well as nebulized albuterol (92852). Additionally, a patient with a history of shortness of breath and cough after consuming a spice mixture containing dried celery had a positive food challenge with 15 grams of cooked celery mixed with different ingredients to mask the taste. The patient's reaction included wheezing, tachycardia, and itching, and treatment required intravenous dexamethasone and clemastinum and intramuscular epinephrine. Notably, prior to the food challenge, the patient had a negative skin prick test to food allergens including celery, but an inhibition assay confirmed cross-sensitivity to mugwort(115301). Another patient with a history of anaphylactic reactions to undeclared celery in restaurant meals was able to undergo desensitization with gradually increasing oral doses of celery juice over several months, and then chronic daily ingestion of the juice to maintain hyposensitization (40908).
General
...Orally, chlorella is generally well-tolerated.
Most Common Adverse Effects:
Orally: Allergic reactions, abdominal cramping, constipation, diarrhea, fatigue, flatus, nausea, photosensitivity, and stool discoloration.
Serious Adverse Effects (Rare):
Orally: Anaphylaxis.
Dermatologic ...Orally, photosensitivity reactions have occurred following ingestion of chlorella (3900,5852). According to case reports, five patients who had ingested chlorella exhibited swelling followed by erythematopurpuric lesions on sun-exposed areas of the body (5852). The photosensitizing agent in the chlorella tablets was identified as pheophorbide-a and its ester.
Gastrointestinal
...Orally, chlorella can cause diarrhea, abdominal cramping, flatus, and nausea, especially during the first two weeks of treatment (5890,6804,92130,92132).
In one clinical trial, one out of 42 patients reported nausea and one reported diarrhea (92132). In another trial, taking chlorella tablets (Sun Chlorella A, Sun Chlorella Corp) and a chlorella extract (Wakasa Gold, Sun Chlorella Corp) resulted in transient worsening of constipation in 4 of 13 patients and transient mild diarrhea in 2 of 13 patients (92130).
Green discoloration of the feces has also been reported, due to the chlorophyll content of chlorella (6804,95013).
Hematologic ...Orally, chlorella has been linked to one case of thrombocytopenia; however, causality has not been determined. A 49-year-old female living in Turkey presented with thrombocytopenia (a platelet count of 27,000/mm3) after taking chlorella 1080 mg daily for 20 days. Platelet counts had been normal one month earlier, and returned to normal two weeks after discontinuing the chlorella supplement (99879).
Immunologic ...Allergic reactions, including asthma and anaphylaxis, have been reported in people taking chlorella and in those preparing chlorella tablets (3900,5847,41827,105645).
Neurologic/CNS
...Orally, manganese (Mn)-induced parkinsonism has been reported after long-term consumption of chlorella extract.
In this case, a patient on maintenance hemodialysis reported gait disturbance, dysarthria, elevated serum and cerebrospinal fluid manganese levels, and abnormal magnetic resonance imaging (MRI) findings of the brain. The authors identified the condition as a rare case of Mn-induced parkinsonism, which may have been due to long-term ingestion of a chlorella extract containing 1.7 mg of Mn in the usual daily dose. The patient underwent edetic acid infusion therapy, which improved the MRI abnormalities and the other symptoms improved four months later (41817).
In one study, fatigue was reported in 18 of 41 patients receiving chlorella 200 mg (10388).
General
...Orally, dandelion seems to be well tolerated.
Most Common Adverse Effects:
Orally: Diarrhea, heartburn, and stomach discomfort.
Topically: Dermatitis in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Anaphylaxis in sensitive individuals.
Cardiovascular ...In one report, a 39-year-old obese woman developed palpitations and syncope after taking a weight loss supplement containing a combination of dandelion, bladderwrack, and boldo for 3 weeks. The patient was found to have prolonged QT-interval on ECG and frequent episodes of sustained polymorphic ventricular tachycardia (14321). It is not clear whether dandelion, another ingredient, or the combination of ingredients is responsible for this adverse effect. The product was not analyzed to determine the presence of any potential toxic contaminants.
Dermatologic ...Topically, dandelion can cause contact dermatitis and erythema multiforme in sensitive individuals. Dandelion can cause an allergic reaction in individuals sensitive to the Asteraceae/Compositae family (13478,13481,42893,46945,46977). Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many other herbs.
Endocrine ...In one report, a 56-year-old man with renal impairment developed hyperoxalaemia and peripheral gangrene after ingesting large amounts of dandelion tea (10 to 15 cups daily for 6 months). The adverse effect was attributed to the high oxalate content of dandelion tea (258 mcmol/L) and reduced renal oxalate clearance caused by renal impairment (90639). In another report, a 58-year-old woman with type 2 diabetes who was being treated with insulin developed hypoglycemic symptoms 2 weeks after beginning to eat salads containing dandelion (46960). The hypoglycemic effect was attributed to the potential alpha-glucosidase inhibitory activity of dandelion.
Gastrointestinal ...Gastrointestinal symptoms, including stomach discomfort, diarrhea, and heartburn, have been reported following oral use of dandelion (19146,36931). A case of intestinal blockage has been reported for a patient who ingested a large amount of dandelion greens three weeks after undergoing a stomach operation (46981). Also, a case of hemorrhagic cystitis has been reported for a 33-year-old woman who took a specific herbal product (Slim-Kombu, Balestra and Mech, Vicenza, Italy) containing 20 herbal extracts, including dandelion extract. Symptoms resolved after the patient discontinued using the product, and symptoms resumed when the patient began taking the supplement again four months later. While various ingredients in the supplement may have contributed to the symptoms, it is possible that dandelion extract may have contributed to the effect due to its diuretic, laxative, cholagogue, and antirheumatic properties (46959).
Other ...Orally, products containing dandelion pollen can cause allergic reactions, including anaphylaxis (13479,13480). Also, rhinoconjunctivitis and asthma have been reported after handling products such as bird feed containing dandelion and other herbs, with reported positive skin tests for dandelion hypersensitivity (46948). Dandelion pollen may cause pollinosis, such as allergic rhinitis and conjunctivitis (18065,46951,46964,46966,46972).
General
...Orally, fenugreek seed is generally well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, bloating, diarrhea, dyspepsia, flatulence, hypoglycemia, and nausea.
Serious Adverse Effects (Rare):
All ROA: Severe allergic reactions including angioedema, bronchospasm, and shock.
Endocrine ...Orally, large doses of fenugreek seed, 100 grams daily of defatted powder, have caused hypoglycemia (164,96068).
Gastrointestinal ...Orally, fenugreek seed can cause mild gastrointestinal symptoms, such as diarrhea, dyspepsia, abdominal distention and pain, nausea, and flatulence, especially when taken on an empty stomach (622,12534,18349,93421,96065,96068,105016).
Immunologic ...Fenugreek can cause allergic reactions when used orally and topically, and when the powder is inhaled (719,96068). Orally, fenugreek has caused bronchospasm, diarrhea, and itching, and skin reactions severe enough to require intravenous human immunoglobulin (96068). Topically, fenugreek paste has resulted in facial swelling, wheezing, and numbness around the head (719,96068). When used both orally and topically by a single individual, asthma and rhinitis occurred (96068). Inhalation of fenugreek powder has resulted in fainting, sneezing, runny nose, and eye tearing (719,96068).
Neurologic/CNS ...Orally, loss of consciousness has occurred in a 5 week-old infant drinking tea made from fenugreek (9782). Dizziness and headaches have been reported in clinical research of fenugreek extract (49551,93419). However, these events are rare.
Renal ...Orally, fenugreek aqueous see extract may increase the frequency of micturition, although this even appears to be rare (49551).
Other
...Consumption of fenugreek during pregnancy, immediately prior to delivery, may cause the neonate to have an unusual body odor, which may be confused with maple syrup urine disease.
It does not appear to cause long-term sequelae (9781). This unusual body odor may also occur in children drinking fenugreek tea. A case of a specific urine and sweat smell following oral fenugreek extract use has been reported for a patient in one clinical trial (18349).
In 2011, outbreaks of enteroaggregative hemorrhagic Escherichia coli (EATEC) O104:H4 infection occurred in Germany and Spain. Epidemiological studies linked the outbreaks to fenugreek seeds that had been imported from Africa. However, laboratory analyses were unable to isolate the causative strain of bacteria from fenugreek seed samples (49776,49777,49781,90114).
General
...Orally, FOS are generally well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, bloating, flatulence.
Gastrointestinal ...Orally, FOS may cause flatulence, belching, abdominal pain, intestinal sounds, constipation, and bloating. These symptoms can occur commonly in some patients, but are generally mild at doses under 10 grams per day (745,750,8509,98651,107931). However, a meta-analysis of 8 small clinical studies shows that taking FOS at doses ranging from 2.5 grams to 15 grams daily for up to 8 weeks does not increase the rate of abdominal pain, bloating, flatulence, or intestinal sounds when compared with control groups (110710).
General
...Orally, grapefruit and grapefruit juice are generally well tolerated.
Serious Adverse Effects (Rare):
Orally: Allergic reactions in sensitive individuals have been reported. When large quantities are consumed, arrhythmias, mineralocorticoid excess, QT prolongation, and pseudohyperaldosteronism have been reported. There is also some concern for increased breast cancer risk with grapefruit consumption.
Cardiovascular ...Orally, consumption of pink grapefruit juice 1000 mL can cause QT prolongation and cause arrhythmias in healthy patients and worsen arrhythmias in cardiomyopathy patients (13031,91424).
Endocrine ...Orally, high doses of grapefruit juice have been observed to cause pseudohyperaldosteronism and mineralocorticoid excess (53340,53346).
Gastrointestinal ...In a case report, grapefruit juice held against the teeth resulted in enamel and tooth surface loss (53368).
Immunologic ...Orally, grapefruit can cause allergic sensitization characterized by eosinophilic gastroenteritis, urticaria, and generalized pruritus (53351,53360).
Oncologic ...Preliminary population research shows that postmenopausal adults who consume a quarter or more of a whole grapefruit daily have a 25% to 30% increased risk of developing breast cancer (14858). Grapefruit is a potent inhibitor of cytochrome P450 3A4, which metabolizes estrogen. Consuming large amounts of grapefruit might significantly increase endogenous estrogen levels and therefore increase the risk of breast cancer. More evidence is needed to validate these findings. Until more is known, advise patients to consume grapefruit in moderation.
Renal ...In population research, consumption of 240 mL/day of grapefruit juice is associated with an increased risk of kidney stones (4216,53372).
General
...Orally, milk thistle is well tolerated.
Most Common Adverse Effects:
Orally: Abdominal bloating, diarrhea, dyspepsia, flatulence, and nausea. However, these adverse effects do not typically occur at a greater frequency than with placebo.
Serious Adverse Effects (Rare):
Orally: Allergic reactions, including anaphylaxis, have been reported.
Dermatologic ...Orally, milk thistle may cause allergic reactions including urticaria, eczema, skin rash, and anaphylaxis in some people (6879,7355,8956,63210,63212,63238,63251,63315,63325,95029). Allergic reactions may be more likely to occur in patients sensitive to the Asteraceae/Compositae family (6879,8956). A case report describes a 49-year-old female who developed clinical, serologic, and immunopathologic features of bullous pemphigoid after taking milk thistle orally for 6 weeks. Symptoms resolved after treatment with prednisone and methotrexate (107376). Topically, milk thistle can cause erythema (110489).
Gastrointestinal ...Mild gastrointestinal symptoms have been reported, including nausea, vomiting, bloating, diarrhea, epigastric pain, abdominal colic or discomfort, dyspepsia, dysgeusia, flatulence, constipation, and loss of appetite (2616,6879,8956,13170,63140,63146,63160,63210,63218,63219)(63221,63244,63247,63250,63251,63320,63321,63323,63324,63325)(63327,63328,95024,95029,107374,114914). There is one report of a 57-year-old female with sweating, nausea, colicky abdominal pain, diarrhea, vomiting, weakness, and collapse after ingesting milk thistle; symptoms subsided after 24-48 hours without medical treatment and recurred with re-challenge (63329).
Musculoskeletal ...In one clinical study three patients taking milk thistle 200 mg orally three times daily experienced tremor; the incidence of this adverse effect was similar for patients treated with fluoxetine 10 mg three times daily (63219).
Neurologic/CNS ...With oral milk thistle use, CNS symptoms have been reported, including headache, dizziness, and sleep disturbances (114913,114914).
General
...Orally, spinach is well tolerated when consumed as a food.
Serious Adverse Effects (Rare):
Orally: In infants under 4 months of age, methemoglobinemia has been reported.
All routes of administration: Allergies in sensitive individuals.
Dermatologic ...Topically, contact dermatitis has been reported from spinach in a 54-year-old female farmer (41757).
Gastrointestinal ...Bagged spinach has been linked to Escherichia coli outbreaks, sometimes causing severe gastrointestinal symptoms and even death (75846,75847,75849,75851,96858).
Hematologic ...Orally, spinach ingestion by infants under 4 months of age can cause methemoglobinemia, due to its high nitrate content (75802,75858,75860,75861,75862).
Immunologic ...Orally, topically, and via inhalation, spinach has been reported to cause allergic reactions in sensitive individuals (75870,96859).
Pulmonary/Respiratory ...Lung inflammation associated with allergic alveolitis has been reported after inhalation of spinach powder (75871). The powder has also been reported to induce occupational asthma in a spinach factory worker (75833).
General
...Orally, tomato leaves and ripe or unripe tomato fruit are well tolerated in typical food amounts.
Tomato extracts also seem to be well tolerated. Tomatine, a glycoalkaloid found in tomato leaves and unripe green tomatoes, can cause serious side effects when consumed in excessive amounts.
Serious Adverse Effects (Rare):
Orally: Bradycardia, diarrhea, respiratory disturbances, spasms, vomiting, and death with excessive consumption of tomatine, a glycoalkaloid found in tomato leaves and unripe green tomatoes.
Cardiovascular ...Orally, the glycoalkaloid tomatine in tomato leaf or green tomatoes can cause bradycardia when consumed in excessive amounts (18,102957).
Gastrointestinal ...Orally, the glycoalkaloid tomatine in tomato leaf or green tomatoes can cause severe mucous membrane irritation, vomiting, diarrhea, and colic when consumed in excessive amounts (18,102957).
Immunologic ...In a case report, a 31-year-old female working in the supermarket developed an airborne allergy to tomato stem proteins with symptoms of severe rhinoconjunctivitis. This woman did not have a food allergy to tomato fruit (102467).
Neurologic/CNS ...Orally, the glycoalkaloid tomatine in tomato leaf or green tomatoes can cause dizziness, stupor, headache, and mild spasms when consumed in excessive amounts (18,102957).
Pulmonary/Respiratory ...Orally, the glycoalkaloid tomatine in tomato leaf or green tomatoes can cause respiratory disturbances when consumed in excessive amounts. In severe cases, death by respiratory failure might occur (18,102957).
General
...Orally, wheatgrass is generally well tolerated.
Most Common Adverse Effects:
Orally: Allergic reactions, anorexia, constipation, nausea.
Gastrointestinal ...Orally, wheatgrass may cause nausea, anorexia, and constipation (11165).
Immunologic ...Wheat can cause allergic reactions in sensitive individuals. Due to the prevalence of this allergy in the general population, wheat and wheat products, such as wheatgrass, are classified as major food allergens in the United States (105410).
