2017 HCHB_digital

Herbal Supplements: Interactions
POTENTIAL INTERACTIONS BETWEEN DRUGS AND PHYTOMEDICINES
Herbal Supplements – Interactions
Herb/herb group Possible interacting drugs Possible interaction(s) References
Aloe vera gel and juice
American ginseng
(Panax quinqefolium)
Andrographis
(Andrographis paniculata)
Oral hypoglycaemic drugs
(eg, glibenclamide)
Increased hypoglycaemic effects possible
Vitamin C and E Increased absorption possible 1
Antipsychotics
Possible potentiation of antipsychotic properties suggested
Improvement in working memory & reduced extrapyramidal effects
Oral hypoglycaemics Possible enhancement of hypoglycaemic effect 242
Warfarin
Reduced plasma levels in healthy males after two weeks ginseng
administration
Cisplatin Potentiation of in vitro antitumour action by andrographolide 217
Etoricoxib
Reduced etoricoxib bioavailability with large doses of Andrographis or 248
andrographolide reported in rats
Nabumetone
Reduced Cmax and AUC of nabumetone, and compromised its antiarthritic 257
activity in rats
Naproxen
Reduced oral bioavailability of naproxen in rats, but increased anti-arthritic 258
activity
Theophylline Drug bioavailability reduced in studies on rats 216
Aniseed essential oil Paracetamol Reduced paracetamol bioavailability reported in mice 259
Anthraquinone laxatives Cisplatin Reduced anti-cancer activity implicated by in vitro study involving aloe emodin 2
Anxiolytics (eg, valerian,
kava, passionflower, hops)
Anti-platelet agents
(eg, ginger, garlic, clove,
feverfew)
Digoxin and other cardioactive glycosides Potassium depletion (hypokalaemia) leading to increased risk of cardiac 3, 4
toxicity, if large doses used
Thiazide diuretics Potassium depletion 3, 4
Hypnotics, tranquillisers, opiates
and some analgesics acting as CNS
depressants
Anticoagulants (eg, warfarin, heparin)
223
243
Additive CNS depressant effects, particularly with large doses 5, 6
Potentiation of anticoagulant effect and bleeding theoretically possible with
large doses
Bacopa monnieri Thyroxine Possible potentiation of thyroid hormone effects 8
Baical skullcap
(Scutellaria baicalensis)
Cyclosporin
Possible reduction in bioavailability of oral cyclosporin if co-administered with 9
large doses Baical skullcap
Grape seed Potentiated antioxidant effects 10
Etoposide Possible potentiation of antitumour action, by wogonin 218
Mefenamic acid
Potentiation of anti-inflammatory effects & reduction in gastric ulcer adverse 249
effects in rats
Methotrexate Large doses increased methotrexate bioavailability in rats 260
Rosuvastatin Reduced plasma oncentrations of rosuvastatin possible 11
Barberry
Antihypertensives Possible enhanced hypotensive effect, with large doses of fruit extract 12
(Berberis vulgaris)
Berberis vulgaris Losartan Berberine increased Cmax and AUC of losartan in rats (inhibition of CYP3A4 261
proposed)
Betel nut
Antipsychotic drugs Increased parkinsonian side effects reported with flupenthixol and fluphenazine 13
(Areca catechu)
Bilberry Warfarin Possible potentiation of anticoagulant activity, with high doses 14
Bitter melon
(Momordica charantia)
Blackseed
(Nigella sativa)
Bladderwrack
(Fucus vesiculosus)
Oral hypoglycaemic drugs Increased hypoglycaemic effects possible, if large doses taken 15, 16
Vinblastine Reversal of multidrug resistance reported in vitro 17
Amoxycillin Enhanced parenteral and oral bioavailability reported in rats 225
Ciprofloxacin Possibly reduces potential epileptogenic activity of ciprofloxacin 234
Amiodarone Reduced oral drug bioavailability reported in rats 224
Antithyroid agents (carbimazole, Possible antagonism of antithyroid hormone activity 18, 19
propylthiouracil, etc)
Thyroxine Possible potentiation of thyroid hormone activity 18, 19
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