Plasma pharmacokinetic study of once versus twice daily abacavir as part of combination antiretroviral therapy in children with human immunodeficiency virus-1 infection aged 3 months to less than 36 months

INTERVENTION:

1. At week 0, while children enrolled in the study are on a twice‐daily regimen containing ABC or ABC and 3TC, serial pharmacokinetic samples will be collected 2. Following collection of these samples, children will cross over and begin a regimen of ABC 16 mg/kg once‐daily (and 3TC 8 mg/kg once‐daily if applicable) for at least 12 weeks, with the second pharmacokinetic sample collected at week 4 3. The same daily dose will be maintained within 25% (allowing for dose adjustment for growth as appropriate)

CONDITION:

Paediatric HIV ; Infections and Infestations ; Paediatric

HIV PRIMARY OUTCOME:

Area under curve (AUC), Cmin and Cmax values of ABC after once and twice daily dosing

SECONDARY OUTCOME:

1. AUC, Cmin and Cmax values of 3TC after once and twice daily dosing; 2. Assessment of adherence and satisfaction with twice and once daily dosage regimens, using questionnaires

INCLUSION CRITERIA:

1. Infants and children with confirmed presence of human immunodeficiency virus (HIV‐1) infection 2. Infants and children aged 3 to less than 36 months 3. Parents able/willing to give consent 4. Currently on combination anti‐retroviral therapy (ART) including ABC oral solution or a combination of ABC and 3TC, for at least 12 weeks, and expected to stay on this regimen for at least a further 12 weeks 5. HIV‐1 ribonucleic acid (RNA) viral load ‐ either suppressed HIV‐1 RNA viral load (i.e. less than 400 copies/ml) or non‐suppressed but low HIV‐1 RNA viral load (i.e. 400 ‐ 20,000 copies/ml). The non‐suppressed children should have had a stable or decreasing HIV‐1 RNA viral load prior to study entry and should be considered to still be gaining benefit from the current regimen. 6. Children should have stable or rising cluster of differentiation‐4 (CD4+) cell percentage prior to study entry and their CD4+ cell percentage should not be expected to fall with