Complementary and alternative medicine use among individuals participating in research: implications for research and practice.

Study Objectives. To determine the frequency and type of complementary and alternative medicine (CAM) use among healthy volunteers participating in research, and to investigate the potential for interactions between commonly used CAM modalities and various drugs. Design. Prospective evaluation. Setting. University general clinical research center. Subjects. Sixty healthy adults participating in an ongoing drug study. Measurements and Main Results. The clinical study database was queried to determine the use and type of existing and newly started CAM throughout the study period. Baseline characteristics were compared between users and nonusers of CAM to identify differences between them. Potential CAM-drug interactions were classified based on curated databases and primary literature sources. Of the 60 subjects enrolled, 30 (50%) used CAM during the study. Of these, 26 (87%) were using CAM at study entry. Baseline CAM users were on average 7 years older than nonusers (p=0.03) and had high-density lipoprotein cholesterol concentrations 10 mg/dl higher than those of nonusers (p=0.04). The group using CAM had more women and nonsmokers than the other group. Several potential CAM-drug interactions were identified. Conclusion. Because of high rates of CAM use (50% of the subjects were using biologically based CAM) and the many potential CAM-drug interactions, CAM use should be rigorously addressed in clinical practice and research. Failure to capture this information may have clinical repercussions through pharmacokinetic and pharmacodynamic interference of clinical response and clinical trial results. Clinicians and researchers may be able to identify those most likely to use CAM by their baseline characteristics; this would help target those patients and research subjects for more thorough assessment and follow-up.