Adherence to trizivir and tenofovir as a simplified salvage regimen is associated with suppression of viraemia and a decreased cholesterol

Background: Treatment failure during highly active antiretroviral therapy (HAART) is ultimately common and associated with the development of resistance mutations. Trizivir (zidovudine/lamivudine/abacavir) and tenofovir disoproxil fumarate may improve adherence and enhance virological suppression in individuals who have failed previous regimens. Methods: Individuals were identified who had failed previous HAART and who were then prescribed trizivir and tenofovir. Viral load and genotypic information were obtained to assess virological response. Results: One hundred and twenty-two individuals were identified from a database containing 5883 patients. In a last observation carried forward intention to treat analysis, 34% of individuals achieved an undetectable viral load of <50 copies/mL at 1 year. Of those who were able to remain on treatment for 1 year, 65% achieved undetectability. We observed no effect regarding previous regimens on viral outcome. Accumulation of TAMs (thymidine analogue mutations) was associated with a decrease in the number of patients achieving an undetectable viral load (with <2 TAMs present 38% of patients developed undetectable viral loads, ≥2 TAMs 17% undetectable; P = 0.03). Using the mean cell volume as a measure of compliance, those with higher values were more likely to achieve a viral load <50 copies/mL (P = 0.04). A beneficial effect on cholesterol was noted regardless of virological outcome. Conclusions: In compliant heavily pre-treated Individuals with less than 2 TAMs, salvage therapy with trizivir and tenofovir is associated with suppression of viraemia and an improved lipid profile.