Abstract
PURPOSE OF REVIEW: Two-drug regimens (2DR) for antiretroviral therapy are increasingly being recommended for people living with HIV to reduce pill burden and reduce short and long-term toxicity. The exclusion of tenofovir and lamivudine or emtricitabine has implications for acquisition of and reactivation of hepatitis B. RECENT FINDINGS: A number of case-series, cohort studies and randomized-controlled trials of 2Drs have reported on the risk of HBV acquisition and HBV-reactivation (HBVr). The risk of HBVr appears negligible in those switching to 2DRs containing lamivudine, and overall low (~1%) in those switching to tenofovir and lamivudine/emtricitabine-free therapy. Even remote HBsAg positivity is associated with a significant risk of HBVr. SUMMARY: For people with HIV switching to 2DRs careful attention needs to be paid to preswitch HBV serological patterns. For those without previous exposure, and absence of HBsAb, vaccination is important. The risk of HBVr of switching to lamivudine-containing regimens is negligible, and low without tenofovir and lamivudine/emtricitabine. Careful monitoring and preswitch counselling is advised.