Herb-drug interactions: A review and study based on assessment of clinical case reports in literature

Objective : To conduct a systematic review of literature on interactions between conventional drugs and various herbs. Materials and Methods : We carried out a literature survey to assess published herb-drug interaction information in clinical case reports and case series to check the report reliabilities. Results : From 133 cases of suspected interactions, 67% cases were classified as possible interactions, 27% cases were unable to be evaluated and only 6% of the cases were well-documented. St. John's wort was the most common herb involved (37 cases) in drug interactions. Warfarin was the most common drug (34 cases) interacting with various herbs. Conclusion : Herb-drug interactions are a stark reality today. Hence, proper reporting of cases, careful vigilance, evidence-based appraisal and constantly updated reviews of such herb-drug interactions are very important to promote systematic research.