Management of drug interactions in patients with HIV

OBJECTIVE: To provide a compilation of relevant information on drug interactions to assist healthcare practitioners in managing complex HIV-related pharmacotherapy. DATA SOURCES: Information was retrieved via a MEDLINE search (January 1966-December 1996) using MeSH headings ''human immunodeficiency virus,'' ''drug interactions,'' and names of medications commonly prescribed for the management of HIV infection and related opportunistic infections. Abstracts of international and national conferences, review articles, textbooks, and references of all articles were also searched. STUDY SELECTION AND DATA EXTRACTIONS: All literature on pharmacokinetic or pharmacodynamic interactions was considered for inclusion. Pertinent information, as assessed by the authors, was selected and summarized for discussion. DATA SYNTHESIS: Drug disposition and/or pharmacologic effect may be affected either by HIV-related physiologic changes or by the presence of concomitant drug therapy. Modifications in drug selection, dosage, dosing regimen, or route of administration may be needed to avoid or manage drug-disease, drug-drug, or drug-food interactions. Management options may depend on the mechanism and the clinical significance of the interaction, the availability of therapeutic alternatives, patient convenience, and cost restrictions. In the absence of specific data, consideration of pharmacokinetic and pharmacodynamic characteristics to assist practitioners in predicting the likelihood of possible interactions was included. RESULTS: A comprehensive table of clinically significant drug interactions is provided. Drug interaction principles and practical management strategies are also discussed. CONCLUSIONS: The potential for drug interactions is extremely common, given the increasing complexity of managing patients infected with HIV, To avoid compromising therapeutic efficacy or increasing drug toxicity, practitioners need to be aware of potential interactions and are encouraged to use a systematic approach when managing patient drug therapy.