FDA ALERT [7/24/2008]: Serious and sometimes fatal hypersensitivity reactions (HSR) caused by abacavir therapy are significantly more common in patients with a particular human leukocyte antigen (HLA) allele, HLA-B*5701. Abacavir HSR is a multi-organ syndrome characterized by 2 or more clinical signs or symptoms that can include fever, rash, gastrointestinal symptoms, respiratory symptoms and constitutional symptoms.
