St. John's Wort (hypericin extract) is a weak inhibitor of monoamineoxidase A, which may destroy dopamine in the brain and lead to low spirits.*Flavonoids, hypericin, and pseudo-hypericin are the constituents thoughtto be associated with the benefits of St. John's Wort. In particular,hypericin appears to be the active ingredient.27-33

St. John's Wort should not be taken with MAO (monoamine oxidase)inhibitors. Use caution when initiating St. John's Wort if SSRIssuch as Prozac, Paxil, and Zoloft are being taken. St. John's Wortmay reduce the availability of certain prescription drugs such as the anti-HIVdrug, Indinavir. St. John's Wort may cause increased skin sensitivityto UV light. Do not take St. Johns Wort if you are taking any otherprescription drugs. Note caution in reference to SSRIs above.

Adverse interactions have been reported between St. John's wort(hypericum), an herbal product used to treat depression, and two drugs:indinavir, a protease inhibitor used to treat HIV and cyclosporine, a drugused to reduce the risk of organ transplant rejection. Potentially dangerouschanges in drug effects can occur when medications such as cyclosporina(Neoral, Sandimmune), digoxin (Lanoxin, Lanoxicaps) and warfarin (Coumadin)are taken with hypericum extracts. Hypericum extracts can decrease bloodlevels of antiretroviral medications that are used in the treatment ofHIV infection, thus making these drugs less effective. Data show that theplasma levels of the protease inhibitor indinavir (Crixivan) were reducedby more than 50% by hypericum (St. John's wort) products.34-36*