2017 HCHB_digital

Herbal Supplements: Interactions
Herbal Supplements – Interactions
Herb/herb group Possible interacting drugs Possible interaction(s) References
Pomegranate
(Punica granatum)
Pomelo juice
(Citrus maxima)
Psyllium seed
Metformin Reduced metformin Tmax reported in rats 264
Cyclosporin Increased bioavailability reported in healthy volunteers 135
Tacrolimus Case report of increased plasma levels 136
Digoxin, warfarin, lithium, carbamazepine
and possibly other drugs
Decreased absorption from GIT possible, with simultaneously administered
drugs, though controversial
Quercetin Irinotecan Enhanced drug bioavailability suggested by studies on rats 139
Reishi mushroom Benzodiazepines and other sedatives Potentiated hypnotic effects shown in rats 140
(Ganoderma lucidum)
Resveratrol Diclofenac Increased diclofenac bioavailability 266
Rhodiola rosea Losartan Increased oral drug bioavailability reported in rabbits 231
Rhubarb
(Rheum palmatum)
(Rheum officinale)
Cyclosporin Reduced cyclosporin bioavailability reported in rats 265
Digoxin and other cardiac glycosides Potassium loss and thus increased risk of cardiovascular toxicity, with 3, 4
prolonged use or abuse
Methotrexate Increased drug plasma levels reported in rats 239
Rosemary Azathioprine Protection against azathioprine-induced liver toxicity 141
Safflower flowers
(Carthamus tinctorius)
Chemotherapy drugs
Metoprolol
Enhanced intracellular accumulation of doxorubicin and vinblastine reported
in vitro
Reduced metabolism and possible enhanced bioavailability reported in rodent
studies
Sage Azathioprine Protection against azathioprine-induced liver toxicity 141
Salboku-to
(Asian herbal mixture;
contains same herbs as Shosaiko-to,
plus xiao chai hu
tang, poria cocos, Magnolia
officinalis, Perillae frutescens)
Schisandra
(Schisandra chinensis and S.
sphenanthera)
Sedatives
(eg, valerian, hops, kava,
passionflower)
Senna
(Cassia spp)
Senega
(Polygala senega)
Shankhapushpi
(Ayurvedic preparation)
Sho-saiko-to
(Minor bupleurum)
Siberian ginseng
(Eleutherococcus senticosus)
Prednisolone or prednisone Increased steroidal effects possible 143
Ciclosporin A Enhanced oral drug bioavailability at low but not high drug dosages in rats 232
137, 138
Cytotoxics
Possible enhanced cytotoxic effects by large doses due to reversal of multi-drug 144, 145, 146
resistance by gomisin A and schisandrol A
Paclitaxel Enhanced oral drug bioavailability in rats 221
Rapamycin Enhanced oral drug bioavailability in healthy volunteers 233
Tacrolimus
Sedative drugs (eg, benzodiazepines,
clonidine, opioid analgesics,
phenobarbitone)
Cardiac glycosides and antiarrhythmics
(eg, quinidine)
Enhanced oral bioavailability in healthy volunteers. Reduced schisandra lignin 147, 240
plasma levels in rats
Potentiation of sedative effects 6, 117
Hypokalaemia leading to increased risk of cardiac toxicity 3, 4
Hypoglycaemic drugs Possible enhancement of hypoglycaemic effects 148
Phenytoin Decreased phenytoin concentrations, loss of seizure control 149
Carbamazepine Reduced plasma levels measured in rats after large doses 150
Digoxin Interference with certain laboratory serum digoxin measurements reported 151
Slippery elm Various drugs Theoretical reduction in absorption and thus clinical effects
Sophora flavescens Various drugs Theoretical enhancement of effects through inhibition of CYP450 3A4 152
(Kushen)
St John’s wort Amitriptyline and nortriptyline Possible reduction in plasma levels and antidepressant effects 153
Atorvastatin Reduced hypocholesterolaemic effects possible 154
Carbamazepine Theoretical reduction in plasma levels although no effects reported clinically 155
Cisplatin
Possible protection against cisplatin nephrotoxicity by pre-treatment with large
doses
142
212
156
Page 202 HEALTHCARE HANDBOOK 2017-2018 References Charts