<prompt> Testing of HLA-B57:01 is recommended prior to the initiation of this anti-retroviral agentAtazanavirNelfinavirRaltegravirAbacavir  <response>: Ref. KDT. Page. 808AbacavirIt is a potent ARV drug that acts after intracellular conversion to carbovir triphosphate.Resistance to ABC develops slowlyIts oral bioavailability is 80 and it is mainly eliminated by metabolism.The plasma t12 is 11.5 hour, but intracellular t12 of active metabolite is 12 hours.Hypersensitivity reactions such as rashes, fever, flu-like symptoms are the major problems.To avoid anaphylactic reactions in response to the drug HLA-B57:01 testing is mandatory pre-treatment. Avoidance of alcohol is advised. 