 The EMA and FDA recommended weight band dosing for once daily DRVr dosing in children 3 -12 years of age has been derived from pharmacokinetic modelling. Results from population pharmacokinetic modelling and simulation in these children predict similar DRV plasma exposures compared to treatment-naïve adults, but has not been formally studied in the target population. Although no clinical trial was conducted to collect exposure-safety data, the predicted exposures from the once daily dosing is supported by exposures observed in a paediatric clinical trial where twice-daily dosing was administered. To validate the weight band based dosing recommendations, we want to evaluate the pharmacokinetics of DRVr administered once daily, using DRV tablets, in HIV-infected children. 