Treatment of enterococcal endocarditis and bacteremia: Results of combined therapy with penicillin and streptomycin

Abstract

Results are reported of the concurrent administration of penicillin and streptomycin to seven patients with enterococcal endocarditis. An eighth patient infected with a similar organism is included. Two of the seven patients received combined therapy for only brief periods prior to death and are not considered as having had adequate trials of therapy. In the remaining five patients results of the combined treatment were striking, permanent arrest of the infection being readily achieved in four. The fifth patient sustained a questionable relapse and subsequently died. However, there was no evidence of uncontrolled infection. These results are superior to those which have been achieved by the use of penicillin alone. It is believed that this form of therapy represents the treatment of choice for enterococcal endocarditis and bacteremia at the present time. The results appear to represent a summative (synergistic) effect of the two antimicrobial drugs upon the enterococcus in vivo. Evidence for a combined effect in vitro is presented and an hypothesis as to the possible mechanism of such an effect is discussed. The use of combinations of antimicrobial agents appears to offer an effective method of achieving permanent arrest of some infections which can be suppressed only temporarily by the administration of a single drug.