Tenofovir (Viread) is only approved for use in adults over 18 years of age. A small study of 18 children with substantial treatment experience found that tenofovir-containing antiretroviral treatment regimens brought about modest declines in viral loads and increases in CD4 cell counts. However, a third of the children needed to stop tenofovir after experiencing falls in bone density^[1]. This was seen in previous studies of infant monkeys^[2].

In contrast, a small study of HIV-infected children switching from an effective d4T (stavudine, Zerit)-containing regimen to one containing tenofovir found no effect on the bone^[3]. Further studies are required to determine whether reduced bone density is related to the children’s state of health.