July, 2009 – The Pharmacovigilance Initiative at the BC Centre for Excellence in HIV/AIDS received a report of an HLA-B*5701 positive patient who had tolerated long term abacavir therapy, discontinued antiretroviral drugs for several months, then developed a diffuse rash, respiratory distress and fever shortly after re-initiating an abacavir-containing regimen. The symptoms and rapid onset were consistent with a clinical diagnosis of abacavir hypersensitivity reaction.