St. John's Wort and Drug Interactions

Although extracts of St. John's wort (Hypericum perforatum) are safe and may be effective for the treatment of moderately depressed patients, 3 recent reports suggest the potential for serious drug interactions with this herbal remedy.

Acute heart transplant rejection occurred in 2 Swiss patients who were taking hypericum extract for depression while on standard immunosuppressive regimens that included cyclosporine. In both cases, cyclosporine plasma concentrations decreased significantly during coadministration of St. John's wort and returned to therapeutic levels after herbal treatment was discontinued. In addition, a pharmacokinetic study of 8 healthy volunteers at the NIH showed a large reduction of plasma levels of the HIV-1 protease in…