Research · Narrative review
St John's wort (Hypericum perforatum): drug interactions and clinical outcomes
What it found
Documents clinically significant interactions that reduce the effect of warfarin, cyclosporine, HIV protease inhibitors, theophylline, digoxin, and oral contraceptives (via induction of CYP3A4/2C9/1A2 and P-glycoprotein), plus serotonin-syndrome risk with SSRIs and triptans.
- Design
- Narrative review
- Year
- 2002
- Population
- patients taking St John's wort with concomitant prescription medicines
- Intervention
- St John's wort co-administration
- Outcome
- pharmacokinetic and pharmacodynamic drug interactions
- Journal
- British Journal of Clinical Pharmacology
Citation last checked 2026-06-21.