Cloxacillin induced agranulocytosis: A rare adverse event of a commonly used antibiotic.

Cloxacillin, a semisynthetic penicillin is a potent inhibitor of most penicillinase-producing Staphylococci. Use of high doses of Cloxacillin for 6 weeks is recommended for the treatment of infective endocarditis caused by methicillin-susceptible Staphylococcus aureus (MSSA). Here, we report a case of Cloxacillin-induced agranulocytosis in a patient treated for MSSA native tricuspid valve endocarditis, which was resolved after discontinuation of the antibiotic. This case report highlights a rare adverse event of a commonly used antibiotic.