Patient is an HLA-B*57:01 positive, 43-year-old male with a history of diabetes type II and admission 10 weeks ago at another institution for pubic symphysis osteomyelitis and associated pseudomonas. Cefepime IV was started and the patient presented with fevers, aches, agranulocytosis, thrombocytopenia and rash as a suspected side effect of cefepime after 3 weeks of treatment. Cefepime was replaced with piperacillin-tazobactam and symptoms resolved. Question to be resolved is whether an HLA-B*57:01 positive, abacavir sensitive patient could have an agranulocytosis cross reaction to cefepime.