Treatment with tenofovir (Viread) does not affect the growth of children’s bones, according to a small Italian study published in the December 1st edition of the Journal of Acquired Immune Deficiency Syndromes.
Reductions in bone mineral density and bone mineral content have previously been seen in both adults and children treated with tenofovir, but the Italian investigators found that “twelve months of treatment with tenofovir at the indicated dose is not detrimental for bone mineral accrual in HIV-infected children.”
The study involved 16 HIV-positive children aged between six and 18 years of age. All switched from a stable antiretroviral treatment regimen consisting of 3TC (lamivudine, Epivir), d4T (stavudine, Zerit) and a protease inhibitor to a regimen consisting of 3TC, tenofovir and efavirenz (Sustiva). The treatment dose of tenofovir was dependent on body surface area.
All the children had experienced normal growth and sexual development. On entry to the study five were prepubescent, three were in mid-puberty and the remaining eight children were in late puberty.
Bone mineral content and bone mineral density were measured in the lumbar spine region and the whole skeleton using a DEXA scan twelve months before the treatment switch, at the time when treatment was changed, and twelve months later. The investigators calculated expected changes in bone mineral content and bone mineral density using 166 healthy controls. They then plotted changes in bone mineral content and density in the HIV-positive children against age-matched controls.
The 16 HIV-positive children remained well throughout the study period and all maintained a viral load below 50 copies/ml after the treatment switch. The investigators found that after the switch to tenofovir the children had increases in their bone mineral density and content which were not significantly different from those seen in the healthy age-matched controls.
“The current study shows that switching antiretroviral treatment to tenofovir does not impair bone mineral accrual in HIV-infected children”, write the investigators.
They suggest that their study may have produced different findings to earlier investigations involving children taking tenofovir because of the universal good health of individuals in their study.
However, the investigators concede, “the small sample size may be a limitation of this study and…that there is a need to confirm the bone safety of tenofovir in a larger number of HIV-infected children.”
Giacomet V et al. 1 12-month treatment with tenofovir does not impair bone mineral accrual in HIV-infected children. J Acquir Immune Defic Syndr 40: 448 – 450, 2005.