Warfarin, St John's wort and INR

摘要

In regards to the article on the management of warfarin therapy, the statement on page 46'drugsthat may increase INR-macrolide antibiotics, imidazole antifungals, sulfamethoxazole/ trimethoprim, amiodarone, statins, some non-steroidal anti-inflammatory drugs and some complementary medicines such as St John's wort' may not be correct. In the literature, St John's wort decreases the INR through induction of cytochrome P450 (CYP)-mediated metabolism of warfarin and increases warfarin clearance.