Objective: The concomitant use of rifampin (RFP) with efavirenz (EFV) or nevirapine (NVP) is frequent in HIV patients with tuberculosis (TB). The necessity of increasing the dose of EFV remains controversial. The aim of the study was to evaluate the outcome of HIV infection in patients treated with non-nucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy (ART) and RFR.
Methods: Retrospective analysis of HIV patients who were simultaneously treated with RFP and NVP or EFV. The dose of EFV was considered to be adjusted in those patients receiving 600 mg when weighing <60 kg and 800 mg if >60 kg and was considered nonadjusted when the dose given was 600 mg in patients >60 kg.
Results: 63 patients were included: 13 received NVP and 50 received EFV-based ART (30 adjusted and 20 nonadjusted). Treatment failure was observed in 7 (53.8%) of the NVP group; 11 (55%) of the nonadjusted EFV group, and 8 (26.7%) of the adjusted EFV group (P = .04). The relative risk (RR) of treatment failure comparing nonadjusted and adjusted EFV was 3.36 (95% Cl, 1.02-11.11). The proportion of treatment failure was 9/18 (50%) in the nonadjusted and 5/27(18.5%) in the adjusted EFV group.
Conclusions: The effectiveness of NVP and nonadjusted EFV was lower than adjusted EFV-based ART. It may be advisable to increase the dose of EFV to 800 mg once daily when administered with rifampin in patients weighing >60 kg.