Adverse events associated with abacavir use in HIV-infected children and adolescents: a systematic review and meta-analysis

Background Concerns exist about the toxicity of drugs used in the implementation of large-scale antiretroviral programmes, and documentation of antiretroviral toxicity is essential. We did a systematic review and meta-analysis of adverse events among children and adolescents receiving regimens that contain abacavir, a widely used antiretroviral drug. Methods We searched bibliographic databases and abstracts from relevant conferences from Jan 1, 2000, to March 1, 2015. All experimental and observational studies of HIV-infected patients aged 0-18 years who used abacavir, were eligible. Incidence of adverse outcomes in patients taking abacavir (number of new events in a period divided by population at risk at the beginning of the study) and relative risks (RR) compared with non-abacavir regimens were pooled with random effects models. Findings Of 337 records and 21 conference abstracts identified, nine studies (eight full-text articles and one abstract) collected information about 2546 children, of whom 1769 (69%) were on abacavir regimens. Among children and adolescents taking abacavir, hypersensitivity reactions (eight studies) had a pooled incidence of 2.2% (95% CI 0.4-5.2); treatment switching or discontinuation (seven studies) pooled incidence was 10.9%(2.1-24.3); of grade 3-4 adverse events (six studies) pooled incidence was 9.9% (2.4-20.9); and adverse events other than hypersensitivity reaction (six studies) pooled incidence was 21.5% (2.8-48.4). Between-study inconsistency was significant for all outcomes (p< 0.0001 for all inconsistencies). Incidence of death (four studies) was 3.3% (95% CI 1.5-5.6). In the three randomised clinical trials with comparative data, no increased risk of hypersensitivity reaction (pooled RR 1.08; 95% CI 0.19-6.15), grade 3 or 4 events (0.79 [0.44-1.42]), or death (1.72 [0.77-3.82]) was noted for abacavir relative to non-abacavir regimens. None of the reported deaths were related to abacavir. Interpretation Abacavir-related toxicity occurs early after ART initiation and is manageable. Abacavir can be safely used for first-line or second-line antiretroviral regimens in children and adolescents, especially in sub-Saharan Africa were HLA B5701 genotype is rare.