Pharmacokinetic (PK) Study of Twice Daily vs Once Daily Lamivudine (3TC) and Abacavir (ABC) as Part of Combination Antiretroviral Therapy (ART) in HIV Infected Children

Inclusion Criteria: * Children with definitive HIV infection * Age \> 2 and \< 13 years * Currently on combination ART including 3TC and / or ABC, for at least 6 months, with stable CD4 cell count and HIV RNA viral load and expected to stay on this regimen for at least a further 3 months. Exclusion Criteria: * • Intercurrent illness * Receiving concomitant therapy except prophylaxis against Pneumocystis carinii pneumonia (PCP) * Abnormal renal or liver function (grade 3 or above)