Ginseng does not appear to affect metabolism of alprazolamor dextromethorphan
Clinical evidence,mechanism, importance and management
A study in 12 healthy subjects found that Siberian ginseng, 485mg twice daily for 14 days, did not affect pharmacokinetics of a single 2mg dose of alprazolam or metabolism of a single 30mg dose of dextromethorphan. This suggests that Siberian ginseng is unlikely to affect metabolism of other drugs that are substrates of cytochrome P450 isoenzymes CYP2D6 or CYP3A4 (See reference number 1). For a list of drugs that are substrates of these enzymes,see table 1 below,, and table 2 below,, respectively.
1. Donovan JL,DeVane CL, Chavin KD, Taylor RM, Markowitz JS. Siberian ginseng (Eleutheroccus [sic] senticosus) effects on CYP2D6 and CYP3A4 activity in normal volunteers. Drug Metab Dispos (2003) 31, 519–22.
| Table 1 Drugs affecting or metabcytochrome P450 isoenzymes | olised by the CY | P2 family of | |
|---|---|---|---|
| Isoenzyme | Inhibitors | Inducers | Substrates |
| CYP2B6 | Thiotepa | Phenobarbital Phenytoin | Cyclophosphamide Ifosfamide |
| CYP2C8 | Gemfibrozil Rifampicin Trimethoprim | Pioglitazone Repaglinide Rosiglitazone | |
| CYP2C9 | Amiodarone Azoles Fluconazole Miconazole Voriconazole Fluvastatin SSRIs Fluoxetine Fluvoxamine Sulfinpyrazone Ticlopidine Zafirlukast | Aprepitant Rifampicin | Irbesartan Losartan Nateglinide NSAIDs Celecoxib Diclofenac Etoricoxib Valdecoxib Phenytoin Statins Fluvastatin Rosuvastatin Sulphonylureas Glibenclamide Gliclazide Glimepiride Glipizide Tolbutamide* S-Warfarin* |
| Table 2 Drugs affecting or metabolised by isoenzyme CYP3A4 | the cytochrome P450 | |
|---|---|---|
| Inhibitors | Aprepitant Azoles Itraconazole Ketoconazole Voriconazole Cimetidine Delavirdine Diltiazem Grapefruit juice Imatinib | Macrolides Clarithromycin Erythromycin Troleandomycin Nefazodone Nicardipine Protease inhibitors SSRIs Fluoxetine Verapamil |