Safety of switching nevirapine twice daily to nevirapine once daily in virologically suppressed patients

Background: The strategy of switching nevirapine (NVP) twice daily to once daily was evaluated. Methods: Forty-eight-week randomized, open, multicenter trial. Stable HIV-infected patients on NVP twice daily for > 12-18 weeks with alanine aminotransferase (ALT) <2.5, the upper normal limit were randomized to continue their regimen or switch to NVP 400 mg once daily. Primary end point was the proportion of ALT/aspartate transaminase (AST) agrade 3. Results: Two hundred eighty-nine patients were included, mean CD4 620 cells per microliter. Noninferiority was demonstrated in the per protocol analysis, with 97.9% (once daily) and 99.3% (twice daily) of patients event free (difference, 1.4%; 95% confidence interval, -1.95% to 5.4%), whereas 81.8% vs. 93.8% were event free by intent-to-treat switch = toxicity analysis (difference, 12%; 95% confidence interval, 4.6% to 19.4%). Only 4 patients (3 once daily, 1 twice daily) had NVP-related grade 3/4 ALT/AST increases, but in 2 of them (once daily), transaminases decreased despite continuation with NVR Two other once daily patients presented grade 3/4 ALT/ AST increase due to well-documented acute hepatitis A virus or hepatitis C virus infection. Grade 2 ALT/AST increases occurred in 11.2% (once daily) vs. 10.3% (twice daily) of patients (P = 0.80). A larger number of once daily patients were lost to follow-up/violated protocol (15% vs. 5%). Conclusions: In patients on standard twice daily NVP-containing regimens for at least 12-18 weeks, per protocol analysis showed that switching to once daily NVP was not inferior to continued twice daily NVP in terms of the predefined noninferiority margin of 10% for hepatotoxicity.