[Prevalence of potential drug-drug interactions involving antiretroviral drugs in Buenos Aires, Argentina].

INTRODUCTION Antiretroviral agents (ARVs) have a high potential for drug interactions. However, the prevalence and risk factors for clinically significant drug-drug interactions (CSDDIs) with ARVs from Latin American countries is unknown. AIM To evaluate the prevalence and risk factors for CSDDIs in HIV outpatients attending at two centers in Buenos Aires, Argentina. METHODS Descriptive cross-sectional study (september to november 2012). HIV-1 infected patients under ARV treatment at the time of the study were randomly assessed for concomitant medication. CSDDIs were screened using the University of Liverpool Drug Interactions Program (www.hiv-druginteractions.org). RESULTS A total of 217 patients were included. Male sex: 64% (CI 95: 57-70). Median age (IQR): 41 (36-48). Presence of comorbidities: 19%. ARV regimen: NNRTI-based: 48%, PI-based: 50% and NNRTI plus PI: 2%. Median of CD4 T-cell count (IQR): 402 cells/mL (235-588). Viral load < 50 copies/mL: 78%. Overall, 64% (CI 95: 57-70) of patients had > 1 co-medication of whom a 49% had at least one CSDDI. Two patients had a CSDDI between ARVs. The most frequent co-medications observed were antimicrobial (40%), cardiovascular (25%) and gastrointestinal agents (22%). In the multivariate analysis the number of co-medications and use of CNS agents were associated with the presence of CSDDIs. CONCLUSIONS Co-medications and CSDDIs were common in our setting. In this context, training of HIV physicians in drug interactions is of major importance for adequate management of these patients.