Safety of zidovudine dose reduction in treatment‐naïve HIV infected patients. A randomized controlled study (MiniZID)

Background Since S eptember 2014, zidovudine ( ZDV )‐based therapy for HIV has been the preferred second‐line WHO regimen in C ameroon, but its use is limited by the risk of anaemia at standard dosage. We assessed the safety of a reduced vs . standard dose of ZDV to decrease the risk of anaemia in treatment‐naïve, HIV ‐infected individuals. Methods In a prospective, randomized, open‐label trial in an HIV clinic in C ameroon, 142 eligible adults ( CD 4 count < 350 cells/μL) were randomized to receive 24 weeks of a regimen comprising lamivudine plus nevirapine with either a reduced (400 mg) or standard dose (600 mg) of ZDV . The primary endpoint was the proportion of participants with new/worsening anaemia. Results Median age was 35 years; 58.5% were women; median body mass index was 23.2 kg/m 2 . At baseline, median haemoglobin was 11.6 g/ dL , median CD 4 cell count was 163 cells/μL, and median plasma HIV ‐1 RNA load was 5.4 log 10 copies/mL. The proportion of participants with new/worsening anaemia was 37.5% (400 mg ZDV ) and 32.9% (600 mg ZDV ) ( P  = 0.563). Ten patients with severe anaemia required a switch from ZDV to tenofovir (11.4% in standard‐dose arm vs . 2.8% in low‐dose arm; P  =   0.054). At 24 weeks, there was no significant difference between treatment groups, including median CD 4 T‐cell count increases. Conclusions No significant difference was observed in the overall rate of anaemia between HIV ‐infected individuals starting a ZDV ‐based treatment according to a standard‐ or reduced‐dose regimen. Severe anaemia and treatment switches related to study drug, however, were more frequent with 600 mg than 400 mg ZDV .