Tenofovir-Associated Nephrotoxicity in Children with Perinatally-Acquired HIV Infection: A Single-Centre Cohort Study.

Background And Objective: In 2012, tenofovir disoproxil fumarate (TDF) was approved for use in children over 2 years of age at a dose of 8 mg/kg/day, and is the WHO recommended first-line therapy for children over 10 years of age or 35 kg in weight, at 300 mg daily. Whilst postmarketing experience of paediatric TDF is limited, prior off-licence use has occurred at our centre due to its tolerability, efficacy and resistance profiles. In this article we describe a single-centre experience of TDF nephrotoxicity in children aged <16 years.

Methods: We conducted a retrospective case-note audit of children with perinatally-acquired HIV who ever received TDF-based antiretroviral therapy.

Results: From 2001 to December 2013, 70 children [39 (56 %) females] ever received TDF. Median age at the start of TDF treatment was 12 years (interquartile range 10-14). Seven (10 %) children developed asymptomatic renal tubular leak with associated hypophosphataemia (3) and hypokalaemia (1), all resulting in TDF withdrawal and biochemical resolution. Comparison of the nephrotoxic group versus the rest of the cohort showed no significant differences for age, sex, antiretroviral regimen or CD4 count. Lower weight (p = 0.05) and initial dose of TDF received (p = 0.0048) were significantly associated with TDF-induced nephrotoxicity: median dose of TDF (7.8 mg/kg/day) compared with the remainder of the cohort (6.5 mg/kg/day). Concurrent use of protease inhibitors (PIs) with TDF may be a contributing factor to the development of nephrotoxicity (odds ratio 6; 95 % CI 0.7-54; p = 0.111).

Conclusion: Although all children with TDF-associated nephrotoxicity had biochemical resolution on drug withdrawal, renal monitoring of children receiving TDF is important, especially with the co-administration of PIs. Postmarketing surveillance is essential in the paediatric setting.