| Herb (uses) | Drug | Adverse events |
|---|---|---|
| Ginkgo biloba (Alzheimer's and vascular dementia; peripheral vascular disease, erectile dysfunction, and tinnitus) | Aspirin Warfarin (Coumadin) Thiazide diuretic Acetaminophen and ergotamine/caffeine | Spontaneous hyphema Intracerebral hemorrhage Hypertension Subdural hematoma |
| St. John's wort (mild depression) | Protease inhibitors, cyclosporine (Sandimmune), theophylline, warfarin Digoxin (Lanoxin) Selective serotonin-reuptake inhibitors | Induction of CYP450 3A4 system with decreased levels of drugs available Decreased drug absorption from the gut Lethargy/incoherence/mild serotonin syndrome |
| Saw palmetto (benign prostatic hypertrophy) | No specific drug interactions | Headaches, GI upset |
| Ginseng (cure-all herb) | Warfarin | Decreased INR |
| Alcohol | Increased alcohol clearance | |
| Phenelzine (Nardil); MAOI) | Headache, tremor, mania | |
| Yohimbine (sexual dysfunction) | Tricyclic antidepressants | Hypertension |
| Senna, cascara (laxative) | Possible interference with any intestinally absorbed drug | Decreased drug availability |