Herb/Prescription Interactions

Artimisia annua (Sweet Annie)
Don't take if you have ulcers or gastrointestinal disorders, or if you're  taking antacids, sucralfate, proton pump inhibitors, and histamine-receptor antagonists because it increases the production of stomach acid.  Artemisia can induce seizures making antiseizure medications less effective.

Ephedra   
Caffeine, decongestants, stimulants
Don't use ephedrine-containing supplements if they have cardiovascular disease, hyperthyroidism, diabetes mellitus, benign prostatic hypertrophy or glaucoma.

Bilberry
Anticoagulants / Antiplatelets: may increase  the risk of bleeding if used concurrently due to platelet aggregation inhibition and prostaglandin modulation.

Alfalfa
Increases in rate of metabolism of xenobiotics in the liver. May reduce the effect of warfarin. Because of its estrogenic activity, high levels of alfalfa may interfere with contraceptives and hormonal therapy. Alfalfa may increase effects of diuretic medication. Alfalfa supplements may interfere with hypoglycemic agents.

Ashwagandha
May increase the sedative effect of barbiturates.

Black cohosh
Don't take with Tamoxifen itmay have an additive antiproliferative effect. With Chemotherapy drugs it may increase the toxicity of doxorubicin and docetaxel. Black cohosh may interact with drugs that are metabolized by CYP3A4 enzyme.

Borage
Oil may lower the seizure threshold due to its gamma linoleic acid content, when used with Phenothiazines, Tricyclic antidepressants: Theoretically, may lower seizure threshold due to gamma linoleic acid content. Seizures have been documented with evening primrose oil, but not borage oil. NSAIDS interfere with the synthesis of prostaglandin E. and  decrease the effects of borage oil.

Cascara Sagrada
Can cause excessive loss of potassium with diuretics. Used with Digoxin may potentiate cardiac effects.

Cats Claw
May have an additive or synergistic hypotensive effect with Antihypertensives. May have an additive anticoagulant effect with Anticoagulants / Antiplatelets. In-vitro, cat's claw inhibits CYP3A4, may increase the serum levels of drugs such as protease inhibitors, nonnucleoside reverse- transcriptase inhibitors, cyclosporine, some benzodiazepines, and others.

Chamomile
Anticoagulants / Antiplatelets (warfarin/Coumadin, ect.) may increase the  anticoagulant effects and inhibit platelets due to coumarin content.

Chasteberry
Don't take if you're taking hormonal medications, birth control pills, it may interfere with their effects.Don't take if you're taking dopamine D2-antagonists, such as chlorpromazine, haloperidol, or prochlorperazine.

Chrysanthemum may have an additive hypotensive effect.

Dandilion
Toxicity to lithium may be worsened due to sodium depletion . May have additive effects due to diuretic activity.  Hypoglycemics: may have additive effects due to hypoglycemic activity.

Devils Claw
May reduce efficacy due to increased production of stomach acid if taken with Antacids / H2 Antagonists. With Beta blockers / Digoxin: Devil's claw may cause bradycardia and weaken heart contractions and coronary blood flow. May also have additive anticoagulant activity.

Echinacea
May increase the blood-thinning ability of Coumadin, also known as Warfarin. Echinacea can cause liver toxicity. It should be avoided in combination with other medications that can affect the liver (such as ketaconazole, leflunomide (Arava), methotrexate (Rheumatrex), isoniazide (Nizoral).

Fenugreek
Anticoagulants & Fenugreek  have effects due to coumarin content. With Antidiabetic agents: possible enhanced glucose-lowering effects. Insulin dosage may have to be adjusted with regular use of fenugreek. Absorption of other oral medications may be impaired due to high mucilaginous fiber content of fenugreek seeds. MAOIs & Fenugreek may potentiate their effect due to amine content.

Feverfew
Believed to be the natural remedy for migraine headaches, should never be taken with Imitrex or other migraine medications. It can result in the patient's heart rate and blood pressure to rise dangerous levels. May have additive effect if used with Anticoagulants / Antiplatelets.

Garlic
May decrease the effectiveness of several antihypertension drugs, as well as birth control pills.
Garlic capsules combined with diabetes medication can cause a dangerous decrease in blood sugars. Some people who are sensitive to garlic may experience heartburn and flatulence. Garlic has anti-clotting properties. Garlic might speed how the body breaks down estrogen found in some birth control pills  and may decrease their effectiveness.
 
Germander
May have additive toxicity with other drugs known to cause renal (e.g. aminoglycosides), hepatic, neurotoxicity (e.g.taxanes), or myelosuppression.

Ginkgo biloba   
Has potential interactions with garlic, vitamin E and medications with antiplatelet or anticoagulant properties. Aspirin, warfarin (Coumadin), ticlopidine (Ticlid), clopidogrel (Plavix), dipyridamole (Persantine),

Ginseng-
With Warfarin can increase blood pressure, making it dangerous for those trying to keep their blood pressure under control. Should never be taken with the blood-thinning drug, Coumadin. In rare cases, ginseng may overstimulate resulting in insomnia. Consuming caffeine with ginseng increases the risk of overstimulation and gastrointestinal upset.
Hexobarbital: Eleuthero inhibits metabolism possibly by inhibition of cytochrome p450 2C19.
Digoxin: Elevate serum digoxin levels.
Monomycin / Kanamycin: Increases efficacy of these antibiotics due to enhanced T-lymphocyte activity.

Siberian Genseng
And Insulin / hypoglycemics: Theoretical additive hypoglycemic effect.

Goldenseal
Active ingredient will raise blood pressure, interfering antihypertensive medications, especially beta-blockers. For patients taking medication to control diabetes or kidney disease, this herb can cause dangerous electrolyte imbalance. High amount of consumption can lead to gastrointestinal distress and possible nervous system effects. Not recommended for pregnant or lactating women.

Gotu Kola
Theoretically gotu kola may interfere with blood glucose levels when taking Hypoglycemics / Insulin.Gotu kola may interfere with cholesterol lowering agents.

Guarana
If you are taking any medication that advises you against taking any drink with caffeine, you should avoid taking this stimulant. It may cause insomnia, trembling, anxiety, palpitations, urinary frequency, and hyperactivity. Avoid during pregnancy and lactation period. Long term use of Guarana may lead to decreased fertility, cardiovascular disease, and several forms of cancer.

Guggul
May increase the effects of aspirin, NSAIDs and warfarin.  May have thyroid stimulating activities.
Guggul can induce CYP3A4 activity and may interact with substances metabolized by the same enzyme.

Hawthorn
May be effective in reducing angina attacks by lowering blood pressure and cholesterol levels, should never be taken with Lanoxin (digoxin), for heart ailments. The mix can lower your heart rate too much, causing blood to pool, bringing on possible heart failure.

Kava
Sedatives, sleeping pills, antipsychotics, alcohol.  Kava  has antianxiety, pain relieving, muscle relaxing and anticonvulsant effects, should not be taken together with substances that also act on the central nervous system, such as alcohol, barbiturates, anti depressants, and antipsychotic drugs.

Lavender
May increase or potentiate the CNS depressant effects of sedative or hypnotics drugs.

Myrrh
With Diabetes therapy: Interaction with antidiabetic therapy is possible as hypoglycemic properties have been documented.

Nettle
Don't use if you're taking diclofenac or if you're taking diuretics, nettle can have additive effects.

Passion Flowe
May potentiate the effects of pentobarbital. May increase the sedative effects of benzodiazepines. May have additive anticoagulant effect. May increase the sedative effects of alcohol.

Pau d'arco
May potentiate effects of Anticoagulants /  Antiplatelets.

Red clover
Can increase the risk of bleeding, don't take  if you're taking warfarin or other blood thinners.  Red clover may have estrogenic activity and should be avoided if you've got hormone-sensitive diseases such as estrogen receptor-positive breast cancer, ovarian cancer, endometriosis, etc.

Rhubarb
Chronic Use can cause potassium loss due to stimulant laxative effect, increase potential risk for hypokalemia.  Don't use with Digoxin.

Salvia divinorum (Diviner's sage)
May alter the analgesic effects of other opioids.

Sassafras
Can have an additive effect if you're taking barbiturates such as phenobarbital .

Stevia
With Verapamil: may have additive antihypertensive effects. With Diabetes drugs: it may affect blood glucose level, so cautious use is advised.

St. John's wort
Antidepressants & or over-the-counter diet medications can cause blood pressure to shoot up. Should be avoided in combination with other medications that can affect sun sensitivity (such as tetracycline/Achromycin, sulfa- containing medications, piroxicam (Feldend). St. John's wort can also cause headaches, dizziness, sweating, and agitation when used in combination with serotonin reuptake inhibitor medications such as fluoxetine (Prozac) and paroxetine (Paxil).

Yerba Mate
Effects of aspirin, acetaminophen, diuretics,CNS Stimulants is increased due to caffeine in mate. May increase effects of Theophylline & lead to possible toxicity.  Effects of benzodiazepines are reduced by caffeine content in mate. May alter effects of Clozapine. Mate can cause hypertensive crisis if used with  Monoamine-oxidase inhibitors (MAO-I).

Yohimbe
Can cause hypertension when used with antidepressants.Toxic effects of yohimbine result when used with phenothiazines such as chlorpromazine and promazine. Drugs that are CNS stimulants, such as epinephrine, ephedrine, amphetamines and cocaine, can potentiate the toxic effects of yohimbine. The toxicity of yohimbine may be increased by tranylcypromine and phenelzine. Yohimbine acts synergistically with naloxone resulting in increased anxiety, tremors, palpitations, as well as erections in male subjects.

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Aconite , Cherry Laurel, Hemlock, Nux Vomica, Apple (Balsam) Clematis, Water Hemlock,  Herb  Paris, Bitter Apple, Bolivian Coca, Indian Hemp,      White Poppy,  Baneberry, Indicus Cocculus, Poision  Ivy,   Thornapple, Bloodroot, Ignatius Beans, Meadow  Saffron, Bryony, Hemlock Dropwort,  Laburnum, Spurges, European  Water Bryony, Mountain Laurel,  Stavesacre, Foxglove, Strophanthus, Gelsemium,  Water Lovage, Wake Robin, Cabbage Tree, Black Hellebore, Mescal Buttons, American, Calabar Bean, False Hellebore, Nightshade,  Yew, Calotropis, Green  Hellebore, White Hellebore, Nightshade,
Arnica -Wolf's-bane, Mountain Tobacco; Atropa,  Belladonna; Solanum dulcamara  - Bittersweet; Sanguinaris- Bloodroot; Cytisus scoparius-Spartium, Irish Broom; Aesculus hippocast- Horse Chestnut; Acorus Calamus, Sweet Root; Heliotropium,  Heliotrope; Conium maculatum  Poison Hemlock; Tsuga canadensis, Fool's Parsley; Hyoscyamus, Henbane; Exagonium, Jalap Root; Datura; Jimson Weed, Thornapple; Convallaria, Lily of the Valley; Lobelia, Indian Tobacco, Wild Tobacco; Mandragora  Mandrake; Phoraden- Juniper Mistletoe; Viscum  Mistletoe; Ipomoea,  Morning Glory; Vinca major Periwinkle;
Euonymus,Spindle-tree; Dipteryx,Tonka Bean, Tonco Coumarin; Euonymus  Wahoo Bark; Eupatorium, White Snakeroot; Artemisia Wormwood, (Absinthe), Mugwort;Corynanthe  Yohimbe
REFERENCE:FDA Consumer, October 1983

Possible Herb Side Effects

Aloe is in many products for upset stomachs, inflammation, etc. A potentially harmful chemical contained in aloe can also transfer into breast milk.

Artimisia annua (Sweet Annie)Abdominal pain, Diarrhea Nausea, Flu  symptoms, Decreased appetite, Dermatitis.

Ashwagandha may induce abortion. Extreme caution.

Cascara- contains anthrones, which may cause vomiting and intestinal cramps.
Excessive use can cause diarrhea and weakness. Cascara has been associated with cholestatic hepatitis. The FDA says that is not safe as a stimulant laxative.

Ephedra (ma huang)    Hypertension, insomnia, arrhythmia, nervousness, tremor, headache, seizure, cerebrovascular event, myocardial infarction, kidney stones.

Fenugreek: Doses of 100 g/day cause flatulence, diarrhea, other GI symptoms.
Bleeding, bruising, hypoglycemia. Repeated topical use can cause skin sensitization. Inhalation of the powder can cause asthma and allergic symptoms.

Kava    Sedation, oral and lingual dyskinesia, torticollis, oculogyric crisis, exacerbation of Parkinson's disease, painful twisting movements of the trunk, rash.  Abnormal liver function or damage, occasionally irreversible; deaths reported.

Androstenedione (a steroid)
(4-androstene-3, 17-dione, andro, androstene) Presents increased cancer risk, decrease in HDL cholesterol.

Aristolochia (birthwort, snakeroot, snakeweed, sangrel, asarum canadense, wild ginger. Also in Chinese herbal products labeled fang ji, mu tong, ma dou ling, and mu xiang. Extreme caution: can be an unlabeled substitute for other herbs,eg: akebia, asarum, clematis, cocculus, stephania, and vladimiria species.) A potent human carcinogen; kidney failure, sometimes requiring transplant; deaths reported.
 
Arnica: do not use internally! GI distress, tachycardia, shortness of breath, coma and death. (topical): Contact dermatitis, irritation, burning. External use appears to pose little risk.

Bitter orange(Citrus aurantium, neroli oil, Seville orange, shangzhou zhiqiao, zhi oiao, zhi xhi): Risk of high blood pressure; increased risk of heart arrythmias, heart attack, stroke.

Black cohosh- No conclusive evidence that black cohosh is effective for menopausal symptoms. Don't confuse with blue cohosh. Gastrointestinal upset, hepatotoxicity.

Borage- Constipation, Liver damage if taking borage oil for prolonged periods of time. May cause premature labor.

Burdock (gobo)-  induces low blood sugar (hypoglycemia). Burdock tea has been contaminated with belladonna. Those allergic to chrysanthemums may exhibit cross-sensitivity to burdock.
Can cause uterine stimulation.

Cats Claw- Diarrhea, low blood pressure
Patients w/ systemic lupus erythematosus experienced acute kidney failure after using cat's claw.

Chamomile: Allergic reactions can occur, abdominal cramps, tongue thickness, tightness in the throat, swelling of the lips, throat and eyes, itching all over the body, hives, and blockage of the breathing passages.

Chaparral (Larrea divaricata, creosote bush, greasewood): Abnormal liver function or damage, often irreversible; deaths reported.

Chasteberry- Headaches, stomach upset, nausea, rash, temporary redness, itching, and hives, agitation.

Chrysanthemum- Contact dermatitis, hypersensitivity reaction, photosensitivity.

Comfrey (Symphytum officinale,  salsify, slippery root, symphytum radix, wallwort)
Abnormal liver function or damage, often irreversible; deaths reported.

Dandilion- Heartburn, Stomach inflammation, mild diarrhea, contact dermatitis.

Devils Claw- Diarrhea, slowed heart rate (bradycardia), dispepsia, upset stomach.

Echinacea- Headache, dizziness, nausea
constipation, mild stomach pain, dermatitis, rare serious allergic reaction.

Feverfew-Stomach ache, Mouth ulcers may result from chewing Withdrawals may develop after chronic use,  including muscle stiffness, anxiety, moderate pain, headache, nausea, and vomiting.
Makes alergies worse.

Garlic produces a chemical called allicin, which seems to make it a possibly effective treatment for conditions including high cholesterol, high blood pressure, hardening of the arteries (atherosclerosis), fungal infections on the skin and preventing tick bites.
Garlic might speed up the process by which the body breaks down estrogen found in some birth control pills (contraceptive drugs) and may therefore decrease their effectiveness.

Germander(Teucrium chamaedrys, wall germander, wild germander): Abnormal liver function or damage, often irreversible; deaths reported. Common: Weight loss, fatigue, nausea, vomiting, anorexia, anemia, muscle weakness.

Ginkgo can improve blood circulation, which might help the brain, eyes, ears, and legs function better. May be effective in improving thinking processes  old age and young people; Raynaud's syndrome (a painful response to cold especially in the fingers and toes); leg pain when walking due to poor blood flow (claudication); vertigo and dizziness; premenstrual syndrome (PMS); improving color vision in people with diabetes; and treating some kinds of eye diseases (glaucoma and eye damage caused by diabetes). Ginkgo may effect how much insulin your body makes which might change how much insulin you need to inject. Also, Ginkgo and the pain reliever ibuprofen both can slow blood clotting, therefore, taking them together could thin the blood too much and increase the chance of bruising and bleeding.

Ginseng- Long term use may cause menstrual abnormalities and breast tenderness in some women. Ginseng is not recommended for pregnant or lactating women.

Gotu Kola-Contact dermatitis, itching,
Sensitivity to light, Headache, Reduced fertility. Signs of gotu kola toxicity: Low blood sugar levels, high blood cholesterol levels, sedation.

Guggul: Headache, mild nausea,  hiccups, and loose stools,  Hypersensitivity rash.

Lavender-  quickly absorbed through the skin. Components of the essential oil were found in the blood within 5-20 minutes.  Contact dermatitis, sleepiness.

Lobelia(Lobelia inflata, emetic herb,  indian tobacco, wild tobacco): Risk of Breathing difficulty, rapid heartbeat, low blood pressure, diarrhea, dizziness, tremors; possible death.

Melatonin is a potent hormone. There is some concern that taking melatonin supplements might interfere with development in young adolescents.

Milk Thistle: Diarrhea caused by mild laxative effect; uterine and menstrual stimulation.

Nettle- capsules have been recalled due to lead contamination.

Passion Flower: Dizziness, sedation, ataxia, allergic reaction, and impaired cognitive function

Pennyroyal: Liver and kidney failure, nerve damage, convulsions, abdominal tenderness, burning of the throat; deaths reported.

Rhubarb-Chronic use: Abdominal cramps, nausea, vomiting, diarrhea leading to possible hypokalemia, anaphylaxis, renal and hepatic damage.

Salvia divinorum (Diviner's sage) may result in loss of consciousness. Hallucination, nausea, dizziness, physical exhaustion, lung damage (when inhaled).

Sassafras- has caused liver cancer in laboratory animals. Hot flashes, Profuse perspiration. At high doses or with cronic use, sassafras can cause hallucinations, high blood pressure, fast heart rate, liver cancer and death.

Scullcap (Scutellaria lateriflora): Abnormal liver function or damage.

Stevia- Pregnant women should not consume this herb. Can cause nausea,
stomach fullness.

St. John's wort-    Gastrointestinal disturbances, allergic reactions, fatigue, dizziness, confusion, dry mouth, photosensitivity.

Valerian is safe for most people when used short-term, but can cause some side effects such as headache, excitability, uneasiness, and even insomnia in some people. The long-term safety of valerian is unknown.

White Willow, an herb traditionally used for fever, headache, pain, and rheumatic complaints may lead to gastrointestinal irritation, if used for a long time. It exhibits similar reactions as aspirin (aspirin is derived from white willow). Long term use may lead to stomach ulcers.

Yerba Mate: Insomnia, anxiety, tremor, restlessness, agitation, nausea and vomiting, palpitations and headache.

Yohimbe (Pausinystalia yohimbe): Change in blood pressure, heart arrythmias, respiratory depression, heart attack; deaths reported.

Medicine/Herb/Food Interactions

Alcohol is a drug that interacts with almost every medication, especially antidepressants and other drugs that affect the brain and nervous system.
  
Some dietary components increase the risk of side effects. Theophylline, a medication administered to treat asthma, contains xanthines, which are also found in tea, coffee, chocolate, and other sources of caffeine. Consuming large amounts of these substances while taking theophylline increases the risk of drug toxicity.
   
Large amounts of broccoli, spinach, and other green leafy vegetables high in vitamin K, which promotes the formation of blood clots, can counteract the effects of heparin, warfarin, and other drugs given to prevent clotting.

Cranberries, like many other fruits and berries, contains significant amounts of salicylic acid. Salicylic acid is similar to aspirin.
People who are taking aspirin or are allergic to aspirin should avoid drinking large quantities of cranberry juice.
   
Dietary fiber affects drug absorption. Pectin and other soluble fibers slow down absorption of acetaminophen. Bran and other insoluble fibers have a similar effect on digoxin, a major heart medication.


Cephalosporins, penicillin: Take on an empty stomach to speed absorption of the drugs.

Erythromycin: Don't take with fruit juice or wine, decreases the drug's effectiveness.

Sulfa drugs: Increase the risk of Vitamin B-12 deficiency

Tetracycline: Dairy products reduce effectiveness. Lowers Vitamin C absorption


Fluoxetine:  Reduce appetite and can lead to excessive weight loss

Lithium:   A low-salt diet increases the risk of lithium toxicity; excessive salt reduces the drug's efficacy

MAO Inhibitors:    Foods high in tyramine include aged cheese, chicken liver, Chianti (and certain other red wines), yeast extracts, bologna (and other processed meats), dried or pickled fish, legumes, soy sauce, ale, and beer, can bring on a hypertensive crisis.    

St. John's Wort:mixed  with foods high in tyramine (see above), produces a dangerous food-drug interaction. Symptoms can occur within minutes  including rapid rise in blood pressure, a severe headache, collapse and even death.

Many foods, especially legumes, meat, fish, and foods high in Vitamin C, reduce absorption of the drugs.


ACE inhibitors: Take on an empty stomach to improve the absorption of the drugs.

Alpha blockers:  Take with liquid or food to avoid excessive drop in blood pressure.

Antiarrhythmic drugs:  Avoid caffeine, which increases the risk of irregular heartbeat.

Beta blockers:  Take on an empty stomach. Food, especially meat, increases the drug's effects and can cause dizziness and low blood pressure.

Digitalis: Avoid taking with milk and high fiber foods, which reduce absorption, increases potassium loss.

Increase the risk of potassium deficiency.

Potassium sparing diuretics:  Unless a doctor advises otherwise, don't take diuretics with potassium supplements or salt substitutes, which can cause potassium overload.

Thiazide diuretics:  Increase the reaction to MSG.

Pseudoephedrine:    Avoid caffeine, which increase feelings of anxiety and nervousness.

Theophylline:    Charbroiled foods and high protein diet reduce absorption. Caffeine increases the risk of drug toxicity.

Cholestyramine:    Increases the excretion of folate and vitamins A, D, E, and K.

Gemfibrozil: Avoid fatty foods, which decrease the drug's efficacy in lowering cholesterol.


Antacids:    Interfere with the absorption of many minerals; for maximum benefit, take medication 1 hour after eating.

Cimetidine, Fanotidine, Sucralfate:    Avoid high protein foods, caffeine, and other items that increase stomach acidity.

Oral contraceptives:   Salty foods increase fluid retention. Drugs reduce the absorption of folate, vitamin B-6, and other nutrients; increase intake of foods high in these nutrients to avoid deficiencies.

Salty foods increase fluid retention. Increase intake of foods high in calcium, vitamin K, potassium, and protein to avoid deficiencies.

Iodine-rich foods lower the drugs efficacy.

Mineral Oils    Overuse can cause a deficiency of vitamins A, D, E, and K.

Always take with food to lower the risk of gastrointestinal irritation; avoid taking with alcohol, which increases the risk of bleeding. Frequent use of these drugs lowers the absorption of folate and vitamin C.

Codeine   
Increase fiber and water intake to avoid constipation.

Sleeping Pills, Tranquilizers

Benzodiazepines:  
Never take with alcohol. Caffeine increases anxiety and reduce drug's effectiveness