Drug interactions with botanical products

The use of botanicals by consumers in North American and European countries has significantly increased over the last decade, with one survey showing an almost 10% increase in usage from 1990 to 1997 (1). Although the efficacy of some botanicals has been documented (2), there is concern regarding the perceived safety of these products, particularly with respect to the lack of research and knowledge on botanical-drug interaction potential and significance (3). As more consumers use botanicals for various purposes, the likelihood of concurrent use of botanicals with prescription and/or over-the-counter medications, as well as the potential of pharmacokinetic and/or pharmacodynamic botanical-drug interactions will increase. The survey conducted by Eisenberg et al. (1) reported that as many as 15 million adults in 1997 took botanical supplements concurrently with prescription drugs. Over the subsequent years, there has been no change in this usage pattern, with as many as 16% of consumers surveyed indicating concurrent use of botanical dietary supplements and prescription drugs (4).