Nafcillin-induced thrombocytopenia: An uncommon complication

Drug-induced thrombocytopenia is a challenging clinical dilemma that is often overlooked. Nafcillin is a beta-lactam anti-staphylococcal penicillin antibiotic used as a first-line treatment for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia and severe infections. Nafcillin has been associated with a higher rate of premature antibiotic discontinuation than cefazolin. Here we report a 58-year-old woman with multiple comorbid conditions who presented with a prosthetic right hip joint infection due to MSSA and was treated with nafcillin but developed profound thrombocytopenia due to a possible nafcillin side effect on the 14th day of therapy. Thrombocytopenia resolved after discontinuation of nafcillin, and the patient was treated successfully with cefazolin.