Penicillin-Induced Leukopenia

Abstract
To the Editor: Systemic penicillin therapy is generally the antibiotic treatment of choice in bacterial endocarditis and is commonly given in large doses intravenously for prolonged periods. Complications of treatment, although rare, include hypersensitivity reactions ranging from mild urticaria to fatal anaphylaxis, Central-nervous-system disorders, electrolyte disturbances, acute interstitial nephritis, and hemolytic anemias. We present two cases of penicillin-induced neutropenia — a particularly rare complication.Patient 1 was a 28-year-old man admitted with a clinical diagnosis of bacterial endocarditis. Blood cultures grew Streptococcus viridans sensitive to penicillin. At that time he was receiving no other medications. The hemoglobin was 11.1 . . .