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  » Medical News Archive  »   Selected Herb-Drug Interactions










































































































































































































































































































































HERB COMMON INDICATION DRUG POTENTIAL EFFECT
Alfalfa

( Medicago sativa )
Multiple, including treatment of arthritis, asthma, dyspepsia, hyperlipidemia, and diabetes Anticoagulants 1,2 Contains coumarin constituents and vitamin K; excessive use can interfere with drug therapy
Aloe vera latex Strong cathartic Cardiac glycosides, Thiazide diuretics 3 Can cause electrolyte imbalance and hypokalemia; May potentiate drug toxicity
Angelica ( Angelica archangelica ) Loss of appetite, peptic discomfort Anticoagulants 2 Contains coumarin constituents; may potentiate drug effect
Bearberry

Uva-Ursi ( Arctostaphylos uva-ursi )
Urinary tract antibacterial, astringent, diuretic Urinary acidifiers,


Cranberry Juice 2

______________________

Diuretics 4

______________________

NSAID s 4
Inactivated by urinary acidifiers; active compound released only in alkaline urine.


________________________________________

Decreased drug effect

________________________________________

Increased gastrointestinal irritation
Black cohosh Baneberry, bugwort, Squawroot, Rattleroot ( Cimicifuga racemosa ) Hot flashes, premenstrual discomfort and dysmenorrhea Estrogens,

Oral contraceptives 1,3 ______________________ Antihyperlipidemics 1
Herb affects hypothalamus-pituitary system, decreases luteinizing hormone secretion and binds estrogen receptors

May decrease response to estrogen




________________________________________



Possible additive effect
Borage

( Borago officinalis )
Anti-inflammatory, sedative Anticoagulants,

Antiplatelet agents 2

_________________________ Anxiolytics 2
May prolong bleeding time




________________________________________



Additive sedation
Bromelain ( Ananas comosus) Acute post-operative and post-traumatic swelling Antiplatelet agents 2,5 Increased risk of bleeding
Capsicum ( Capsicum frutescens, C. annum) Shingles, trigeminal and diabetic neuralgia Monoamine oxidase

inhibitors 6

______________________

Antiplatelet agents 2
Herb increases secretion of catecholamines, increases risk of hypertensive crisis

_________________________________________


Increased fibrinolytic activity, may prolong bleeding time
Cascara Bitter bark

( Rhanmus purshiana, Cascara sagrada )
Stimulant laxative Cardiac glycosides,

Thiazide diuretics 3
Can cause electrolyte imbalance and hypokalemia;

May potentiate drug toxicity
Chamomile ( Matricaria recutita) Mild sedative, antispasmodic and antiseptic agent Iron 4



______________________ Anticoagulants 1,4
Tannin content in herb may inhibit iron absorption



___________________________________________




Herb contains coumarin constituents; May interfere with drug effects
Chaste tree berry ( Vitex agnus-castus) Menstrual disorders Dopamine receptor antagonists (i.e., phenothiazines) 3 Herb has dopaminergic effect, may antagonize drug effect
Dong Quai

( Angelica polymorpha, A.dahurica, A.atropurpurea)
Menstrual disorders Anticoagulants, Antiplatelet agents 2 _________________________

Estrogens 1
Herb contains coumarin constituents; Possible additive drug effect ___________________________________________

Herb contains phytoestrogens; May result in estrogen excess
Echinacea ( Echinacea augustifolia, E.pallida) Cold, flu Immunosuppressants 3,7





_________________________ Arniodarone, Anabolic steroids, Ketoconazole, Methotrexate 4
Short-term use: phagocyte production stimulated, counteracts drug effect; Chronic use (>6-8 wk): immunosuppressive, enhances drug effect.


__________________________________________



Increased risk of hepatotoxicity
Evening primrose ( Oenothera biennis) Lower serum cholesterol, atopic eczema Phenothiazines, anticonvulsants, 4,6 ______________________

NSAID s, Corticosteroids,

B-blockers,

Anticoagulants 4,6
Increased risk of seizures in patients taking drug known to lower seizure threshold __________________________________________
Feverfew ( Tanacetum parthenium) Migraine, fever, menstrual problems Anticoagulants Antiplatelet agents 2,4

______________________

NSAID s 4


______________________

Iron 4
Additive anticoagulant, antiplatelet effects; Increased risk of bleeding

___________________________________________

Decreased herbal effect

___________________________________________


Tannin content in herb may inhibit Iron absorption
Garlic ( Allium sativum) Hyperlipidemia Anticoagulants


Antiplatelet agents 2,4

_________________________

Hypoglycemic drugs 3.8
Inhibits platelet aggregation; Additive anticoagulant, antiplatelet effects

___________________________________________

May potentiate drug effect
Ginkgo ( Ginkgo biloba) Varicose veins, intermittent claudication, dementia, vertigo, tinnitus, SSRI- induced sexual dysfunction, cerebral vascular insufficiency Anticoagulants Antiplatelet agents 3,4

______________________


Anticonvulsants 4

_________________________

Tricyclic antidepressants, other drugs that decrease seizure threshold 4
Inhibits platelet aggregation, may have additive anticoagulant, antiplatelet effects

___________________________________________

May increase risk of seizures, decrease drug effect


___________________________________________

Increased risk of seizure
Ginseng

Asian ginseng ( Panax ginseng, P.quinquefolium)
Normalize the body, and provide resistance to stress Hypoglycemic drugs 7.9

_________________________

Furosemide 3

______________________

Digoxin 8


________________________

Monoamine oxidase

inhibitors 4,9

________________________

Anticoagulants, antiplatelet agents 2,4

______________________


Estrogens, corticosteroids 4,9



_________________________

Drugs that cause gynecomastia 3,10 (e.g., calcium channel blockers, cardiac glycosides, methyldopa, phenothiazines, spironolactone)
Herb has hypoglycemic effect

___________________________________________


Decreased diuretic effect

___________________________________________

May increase serum digoxin concentrations

___________________________________________

Headache, visual hallucination, tremor, manic episodes

__________________________________________


Decreased effectiveness of warfarin





_________________________________

Additive drug effects

_________________________________

Herb contains estrone, estradiol, estriol; Has additive estrogenic effects
Goldenseal (Hydrastis canadensis ) Mucosal inflammation, gastritis Anticoagulants 2,8 Contains berberine; inhibits anticoagulant effects
Gossypol Male contraceptive Diuretics 4

______________________

NSAID s 4
Potentiate hypokalemia

___________________________________________

Increased gastrointestinal irritation
Guarana

( Paullinia cupana)
CNS stimulant, potentiate analgesics Anticoagulants 3 Inhibits platelet aggregation, increases risk of bleeding
Hawthorn ( Crataegus laevigata, C.monogyna, C.pinnatifida) Heart disease, sleep disorders angina, Antihypertensives 3

_________________________

Digoxin 4
High dose of herb causes hypotension

___________________________________________


Potentiates drug effect
Hops

( Humulus Lupulus L)
Insomnia Anxiolytics, alcohol 3,6 Potential additive sedation
Horse chestnut (Aesculus hippocastanum) Varicose veins, other venous insufficiencies Anticoagulants 2,3 Herb contains coumarin-like constituent; May increase risk of bleeding
Karela

Bitter melon
Diabetes mellitus Hypoglycemic drugs 4 Potentiates drug effect
Kava-Kava ( Piper methylsticum) Sleep disorders, anxiety Alcohol,

Benzodiazepines,

CNS depressants 3,4,6
Additive sedative effects
Kelp


(Laminaria hyperborea)
Thyroid dysfunction Thyroid hormones 4,7 Herb contains iodine, may interfere with thyroid replacement
Kolanut


Cola, Kola

( Cola nitida)
Use in beverages for caffeine content Theophylline, guarana

caffeine 3,10
Herb contains caffeine, potential additive CNS


stimulation
Lemon balm ( Melissa officinalis L) Insomnia, anxiety CNS depressants 6


__________________________

Thyroid hormones 6
Potentiates CNS depression

___________________________________________

May bind thyrotropin and interferes with therapy
Licorice ( Glycyrrhiza glabra) Expectorant, peptic ulcers Spironolactone 4,7

______________________

Cardiac glycosides, Thiazide diuretics 3,4


_______________________

Corticosteroids,

Cyclosporine 4

_______________________

Monoamine oxidase inhibitors 1
Antagonism of diuretic effect


___________________________________________

Can cause hypokalemia; May potentiate digoxin toxicity



___________________________________________

Herb has immunostimulating effect; May decrease response to the drugs

___________________________________________


Herb contains sympathomimetic amines, increased risk of hypertensive crisis
Ma Huang Ephedra, squaw tea, mormon tea, popotillo, sea grape (Ephedra species) Asthma, weight loss Oxytocin, Methyldopa, B-blockers, Caffeine, Monoamine oxidase inhibitors, Theophylline, Sympathomimetics, St.John's wort, Guanethidine, Cardiac glycosides 3,10 Increased sympathomimetic action; may induce hypertension, CNS stimulation
Passionflower (Passiflora incarnata) Anxiety, restlessness Anticoagulants 2 Excessive dose may increase risk of bleeding
Pau D'Arco Taheebo, Trumpet bush (Lapacho colorado) Antineoplastic Anticoagulants 2,3 May potentiate drug effects
Psyllium

Plantago, plantain (Plantago species)
Bulk-forming laxative, Irritable bowel syndrome, Cholesterol lowering Lithium, digoxin 3, 10

__________________________

Antihyperlipidemics 1

_______________________

Anticoagulants 2
Decreased intestinal drug absorption


___________________________________________

Possible additive effects

___________________________________________

Herb contains vitamin K;

May interfere with anticoagulant therapy
Red clover (Trifolium pratense) Anticoagulants 1,2 Herb contains coumarin; large amount may increase risk of bleeding
Sarsaparilla Diuretic Digitalis, bismuth 3 Increased absorption of digitalis and bismuth
Honduras


(Smilax species)
Drugs metabolized by CYP450 enzymes 3,10 Induces CYP450 enzymes; increases drug elimination
Saw palmetto Sabal, Cabbage palm


(Serenoa repens)
Benign prostatic hyperplasia Iron 7

__________________________

Estrogens 4
Tannin content of herb may limit iron absorption 7


_________________________________________________

Potential additive effects
Senna (Cassia acutifolia, C.augustifolia, Senna alexadrina) Constipation Digitalis, Diuretics 3,10 Chronic use may cause hypokalemia and potentiate drug toxicity
Shankapulshpi ( Ayurvedic preparation) Phenytoin 1,4 Reduced drug concentrations and half-life; Decreased drug effect
Siberian ginseng (Eleutherococcus, senticosus) Improve endurance Digitalis 4 May interfere with drug level assay
St.John's wort (Hypericum perforatum) Depression Antidepressants, sympathomimetic amines,


Ma Huang, pseudoephedrine, yohimbine 3,4

__________________________ Digoxin 11

__________________________ Iron 4

__________________________ Piroxicam, Other photosensitizers 3,4
Herb may have monoamine oxidase inhibitor or selective serotonin reuptake inhibitor effects; Possible hypertensive crisis, serotonin syndromes




___________________________________________

Hypericum extract may reduce peak and trough digoxin concentrations

___________________________________________



Tannin content of herb may limit iron absorption

___________________________________________


Increased risk of photosensitivity, avoid use with UV

light therapy
Turmeric

Tumeric, indian saffron

(Curcuma longa)
Dyspepsia Antiplatelet agents 2 Herb contains curcumin; may potentiate antiplatelet activity
Uzara root

(Uzarae radix)
Diarrhea Digoxin 4,7 Additive digoxin-like cardiac effects
Valerian

(Valeriana officinalis)
Anxiolytics Opiates, Alcohol, Barbiturates,

CNS depressants 3,4
Additive sedation
Wormwood Loss of appetite, dyspepsia Anticonvulsants 4 May lower seizure threshold
Yohimbe

Yohimbine


(Pausinystalia yohimbe)
Impotence Antihypertensives, Caffeine, Ephedrine, Ma Huang 3,10 _______________________

Antidepressants,

St. John's Wort 3
Herb has a2- antagonist activity


My induce hypotension or hypertension, tachycardia.



___________________________________________

May have monoamine oxidase inhibitor activity

NSAID = Nonsteroidal anti-inflammatory drug
    SOURCE:  Published by the University of Michigan Health System Drug Information Service