April 27, 1979

Single-Antibiotic Therapy for Streptococcal Endocarditis

Author Affiliations

From the Department of Medicine, Harvard Medical School (Drs Karchmer, Moellering, Maki, and Swartz), and the Department of Medicine, Infectious Disease Unit, Massachusetts General Hospital (Drs Karchmer, Moellering, and Swartz), Boston. Dr Maki is now with the University of Wisconsin Center for Health Sciences, Madison.

JAMA. 1979;241(17):1801-1806. doi:10.1001/jama.1979.03290430019016

Ninety-nine patients treated with penicillin G potassium, cephalothin sodium, or vancomycin hydrochloride were studied to evaluate single-drug therapy for nonenterococcal streptococcal endocarditis. Eighty-six patients survived; of these, 66 received penicillin alone. The maximum serum bactericidal titer obtained at the expected nadir of serum antibiotic concentration was 1:8 or greater in 70 (95%) of the 74 patients studied. No relapse occurred among the 66 patients treated with penicillin. Only one patient experienced a relapse that occurred following therapy with suboptimal doses of vancomycin. Distinct second episodes of endocarditis occurred in five patients. While 13 patients died, none died of intractable infection. The treatment of endocarditis due to penicillin-susceptible streptococci with high-dose parenteral penicillin or a bactericidal penicillin substitute for four weeks or longer results in bacteriologic cure rates comparable with those achieved with combined penicillin-streptomycin regimens.

(JAMA 241:1801-1806, 1979)