Efficacy and safety of 2-drug regime dolutegravir/lamivudine in pregnancy and breastfeeding – clinical implications and perspectives

Objectives To assess the efficacy and safety of a two-drug regimen (2DR) with dolutegravir (DTG) and lamivudine (3TC) in maintaining viral suppression during pregnancy and breastfeeding, and to evaluate its potential as an alternative to the recommended three-drug regimen (3DR) in preventing mother-to-child transmission (MTCT) of HIV. Methods We present a case of a 34-year-old pregnant woman who, after discontinuing 3DR due to side effects and poor adherence, was switched to DTG/3TC at gestational week 23. Maternal viral load (VL) and infant HIV status were monitored throughout pregnancy and a ten-month breastfeeding period. Data on pharmacokinetic changes in pregnancy and the risks associated with 2DR were reviewed. Results The patient’s VL remained suppressed (<20 copies/mL) from gestational week 23 until the end of the breastfeeding period. A healthy HIV-negative baby was born at 39 weeks, and the child remained HIV-negative after ten months of breastfeeding. The 2DR was well-tolerated, improved adherence, and reduced fetal drug exposure. Despite limited experience with 2DR in pregnancy, no viral rebound occurred, and no adverse effects were observed. Conclusions Although 3DR remains the preferred therapy during pregnancy and breastfeeding, this case indicates that DTG/3TC may be an effective alternative for patients experiencing intolerance or poor adherence to 3DR. Further studies are needed to explore the impact of pharmacokinetic changes in pregnancy on 2DR efficacy and to confirm its safety and role in preventing MTCT.