Streptococcal endocarditis (nonenterococcal, non-group A): single vs combination therapy.

A 14-year experience with streptococcal endocarditis was reviewed. The effect of single vs combination antibiotic therapy on the relapse rate was found to be comparable. Of 68 patients treated, four patients died during therapy. Two of 46 patients receiving single-agent and none of 18 patients receiving combination therapy experienced a relapse. Duration of symptoms before diagnosis was the main risk factor predisposing to relapse, which occurred in two of 13 patients with symptoms for longer than three months and in none of 51 patients with symptoms for three months or less before diagnosis. Combination therapy offered no advantage over a single agent in the latter group. Optimal therapy for patients with symptoms for longer than three months could not be determined in this study. However, no relapses were observed in this high-risk group when a single agent was given for longer than 21 days.