Unboosted Atazanavir in Treatment of HIV Infection: Consideration of Tolerability and Safety While Maintaining Efficacy– Report of Two Cases

Abstract

The World Health Organisation anti-retroviral treatment guidelines for resource limited settings rationalise the recommended standard first and second-line regimens on the basis of their efficacy, tolerability, toxicity, availability of fixed-dose combination and cost. Boosted protease inhibitors, recommended as second line agents in combination with a two drug nucleoside analogue backbone may cause diarrhoea and  gastrointestinal disturbances and this raises tolerability concerns. Dyslipidaemias and hepatotoxicity are also considerable. Ritonavir contributes significantly to these adverse properties. We report two patients who had had hepatotoxicity and intractable diarrhoea while on a boosted protease inhibitor regimen, treated successfully with unboosted atazanavir in combination with two nucleoside analogues. Liver toxicity and diarrhoea resolved,while the patients maintained immunological and virological response to the unboosted atazanavir based regimen. Unboosted  atazanavir is an effective option of therapy in patients with suppressed viral replication and have ritonavir tolerability and safety challenges.