Vancomycin for Staphylococcus aureus endocarditis in intravenous drug users. Antimicrob. Agents Chemother

combination regimens for selected cases of Staphylococcus aureus endocarditis in intravenous drug abusers. Design: Open study of nafcillin and tobramycin or vanco-mycin and tobramycin administered for 2 weeks with no further therapy. Setting: County hospital. Patients: Consecutive sample of 53 intravenous drug abus-ers with relatively uncomplicated right-sided S. aureus endo-carditis, defined by clinical and echocardiography criteria, and without renal insufficiency, extrapulmonary metastatic infectious complications requiring prolonged therapy or sur-gery for cure, meningitis, methicillin-resistant organism, aortic or mitral valve involvement, or pregnancy. Interventions: Nafcillin, 1.5 g intravenously every 4 hours, plus tobramycin, 1 mg/kg body weight intravenously every 8 hours, administered for 2 weeks. Vancomycin, 30 mg/kg per day intravenously, in two or three divided doses, was used instead of nafcillin for patients allergic to penicillin. Measurements and Main Results: Forty-seven of 50 pa-tients (94%; 95 % CI, 87 to 99 +) treated with the nafcillin and tobramycin combination were cured. Only 1 of 3 pa-tients treated with vancomycin plus tobramycin (33%, 95% CI, 2 to 86) was cured. Conclusions: Selected patients with S. aureus endocarditis can be treated safely and effectively with a 2-week course of nafcillin plus tobramycin. Only one of three patients treated with vancomycin plus tobramycin was cured, but three pa-tients are too few to define with confidence the efficacy of this regimen