Publication

Prevalence of comedications and effect of potential drug-drug interactions in the Swiss HIV Cohort Study

Journal Paper/Review - Jan 1, 2010

Units
PubMed
Doi
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Citation
Marzolini C, Battegay M, Back D, Ledergerber B, Khoo S, Vernazza P, Calmy A, Bernasconi E, Cavassini M, Chave J, Furrer H, Fux C, Weber R, Gibbons S, Elzi L, Swiss HIV Cohort Study. Prevalence of comedications and effect of potential drug-drug interactions in the Swiss HIV Cohort Study. Antivir Ther (Lond) 2010; 15:413-23.
Type
Journal Paper/Review (English)
Journal
Antivir Ther (Lond) 2010; 15
Publication Date
Jan 1, 2010
Issn Electronic
2040-2058
Pages
413-23
Brief description/objective

BACKGROUND: Potential drug-drug interactions (PDDIs) might expand with new combination antiretroviral therapies (ART) and polypharmacy related to increasing age and comorbidities. We investigated the prevalence of comedications and PDDIs within a large HIV cohort, and their effect on ART efficacy and tolerability. METHODS: All medications were prospectively recorded in 1,497 ART-treated patients and screened for PDDIs using a customized version of the Liverpool drug interactions database. RESULTS: Overall, 68% (1,013/1,497) of patients had a comedication and 40% (599/1,497) had > or = 1 PDDI. Among patients with comedication, 2% (21/1,013) had red-flag interactions (contraindicated) and 59% (597/1,013) had orange-flag interactions (potential dose adjustment and/or close monitoring required). The latter involved mainly central nervous system drugs (49%), cardiovascular drugs (34%) and methadone (19%). In the multivariate analysis, factors associated with having a comedication were advanced age, female gender, obesity and HCV infection. Independent risk factors for PDDIs were regimens combining protease inhibitors and non-nucleoside reverse transcriptase inhibitors (odds ratio [OR] 3.06, 95% confidence interval [CI] 1.44-6.48), > or = 2 comedications (OR 1.89, 95% CI 1.32-2.70), current illicit drug use (OR 2.00, 95% CI 1.29-3.10) and patients with HCV infection (OR 1.74, 95% CI 1.19-2.56). Viral response was similar in patients with and without PDDIs (84.5% versus 86.4%; P=0.386). During follow-up, ART was modified in 134 patients with comedication regardless of the presence of PDDIs (P=0.524). CONCLUSIONS: PDDIs increase with complex ART and comorbidities. No adverse effect was noted on ART efficacy or tolerability; however, most PDDIs affected comedication but were manageable through dose adjustment or monitoring.