Treatment with the nucleotide analogue tenofovir at double the usual dose is effective in combatting HIV resistant to nucleoside reverse transcriptase inhibitors (NRTIs), findings from a small study suggest. However, further studies are needed to clarify the long-term renal tolerance of this dose.
The focus of the present study was to determine if adding tenofovir double-dose (600 mg/day) could improve the virologic efficacy of a failing combined antiretroviral regimen in patients with NRTI-resistant HIV, lead author Dr. Stephanie Dominguez, from CHU Pitie-Salpetriere in Paris, and colleagues note.
The pilot, open-label study involved 10 patients who were treated with double-dose tenofovir for 4 weeks in addition to their failing regimen. The median viral load and CD4 cell count at baseline were 3.66 log10 copies/mL and 407 cells/microliter, respectively.
The new findings appear in the Journal of Medical Virology for February.
By the end of the study, four patients had experienced a drop in viral load of at least 0.8 log10, which was maintained for up to 24 weeks, the report indicates. The median reduction in viral load was -0.61 log10 and the median increase in CD4+ cell count was 109 cells/microliter.
Treatment with tenofovir at the specified dose increased plasma levels of the drug twofold, but except for one patient who developed de Fanconi syndrome at week 2, no serious drug-related side effects were seen.
"This add-on pilot study supports the concept of double dose tenofovir to overcome virologically the decreased sensitivity of NRTI-resistant viruses," the authors state. "However, given the uncertainty regarding renal long-term tolerance of such a regimen, this regimen needs to be considered carefully within a controlled, clinical trial in salvage therapy."
J Med Virol 2007;79:105-110.
Copyright
© 2007 Reuters Limited. All rights reserved. Republication or
redistribution of Reuters content, including by framing or similar
means, is expressly prohibited without the prior written consent of
Reuters. Reuters shall not be liable for any errors or delays in the
content, or for any actions taken in reliance thereon. Reuters and the
Reuters sphere logo are registered trademarks and trademarks of the
Reuters group of companies around the world.
