Brief Communication: Treatment of Enterococcus faecalis Endocarditis with Ampicillin plus Ceftriaxone

Abstract

High-level aminoglycoside resistance (HLAR) that precludes bactericidal synergism with penicillins or glycopeptides and nephrotoxicity related to aminoglycoside treatment are major problems in treating Enterococcus faecalis endocarditis. To evaluate the efficacy and safety of ampicillin plus ceftriaxone for treating endocarditis due to E. faecalis with and without HLAR. Observational, open-label, nonrandomized, multicenter clinical trial. 13 centers in Spain. 21 patients with HLAR E. faecalis endocarditis and 22 patients with non-HLAR E. faecalis endocarditis. All were at risk for nephrotoxicity related to aminoglycoside use. 6-week course of intravenous ampicillin, 2 g every 4 hours, plus intravenous ceftriaxone, 2 g every 12 hours. Clinical and microbiological outcomes. The clinical cure rate at 3 months was 67.4% (29 of 43 patients) among all episodes. During treatment, 28.6% of patients with HLAR E. faecalis endocarditis and 18.2% of patients with non-HLAR E. faecalis endocarditis died of infection-related causes. The rate of clinical and microbiological cure in patients who completed the protocol was 100% in the HLAR E. faecalis endocarditis group. No episodes of breakthrough bacteremia occurred, although there were 2 relapses in the non-HLAR E. faecalis endocarditis group. Treatment was withdrawn in 1 case because of fever and skin rash. The study had a small sample and was observational. The combination of ampicillin and ceftriaxone is effective and safe for treating HLAR E. faecalis endocarditis and could be a reasonable alternative for patients with non-HLAR E. faecalis endocarditis who are at increased risk for nephrotoxicity.