Understanding drug hypersensitivity: what to look for when prescribing abacavir

Abacavir sulfate is an inhibitor of HIV-1 reverse transcriptase. Approximately 5% of patients given abacavir develop a hypersensitivity reaction, a clinical syndrome thought to be immune-mediated and described previously with many different drugs, including other antiretroviral agents. Although rare, fatal reactions have occurred. Actions aimed at reducing morbidity and risk of fatality with hypersensitivity reactions include patient education, early identification and evaluation of symptoms suggestive of hypersensitivity, and prompt discontinuation of abacavir once the diagnosis has been established.