PREVALENCE AND PATTERNS OF USE OF CONCOMITANT MEDICATIONS AMONG PARTICIPANTS IN 3 MULTICENTER HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-I CLINICAL-TRIALS

Data on the prevalence and patterns of use of concomitant medications among participants in three large phase III clinical trials of zidovud ine (ZDV) in human immunodeficiency virus type 1 (HIV-1) infection wer e analyzed. Overall, 2,801 patients reported 43,331 uses of concomitan t medications. Over 85% of clinical trial participants used one or mor e concomitant medications at some point during the study. Patients wit h acquired immune deficiency syndrome (AIDS) used an average of 7.1 dr ugs per month. Patients with AIDS-related complex (ARC) or who were as ymptomatic used relatively fewer drugs: 3.1 and 2.7 per month, respect ively. Fourteen percent of patients with AIDS used more than 10 concom itant medications per month. The three most commonly utilized classes of drugs were antiinfectives (57%), analgesics or antipyretics (55%), and vitamins (47%). A total of 17% of patients overall and 30% of AIDS patients used acyclovir while on trial. Consumption of prescription d rugs was greater, and ''over-the-counter'' drugs less, among AIDS pati ents. Reported use of agents not approved by the Food and Drug Adminis tration or approved drugs used for off-label indications was infrequen t. Overall use of concomitant medications did not differ across demogr aphic subgroups when corrected for disease stage at the time of enroll ment. White, non-Hispanic, homosexual and bisexual men consumed signif icantly more antivirals and vitamins than other trial participants. Wo men in all three protocols took more analgesics or antipyretics than d id men. Characterization of concomitant medication use in clinical tri als may allow the design of studies that better reflect current clinic al treatment standards and patient preferences, contribute to a more a ccurate evaluation of drugs being investigated, and provide preliminar y indication of effects, toxicities, and costs of commonly used medica tions specifically in HIV-infected patients. As the number of agents d emonstrated to be efficacious in the treatment of HIV infection and th e potential for significant drug interaction increase, the assessment of concomitant medication use by HIV-infected patients will be vitally important.