What is a common treatment for infective endocarditis from a prosthetic valve?

The combination of ampicillin/sulbactam and gentamicin is a common and effective treatment regimen for infective endocarditis associated with prosthetic valves, especially in cases caused by susceptible strains of bacteria. This regimen targets a broad range of gram-positive and some gram-negative organisms, which is crucial for managing endocarditis.

Ampicillin provides excellent coverage against Streptococcus and Enterococcus species, which are often responsible for infections related to prosthetic valves, while sulbactam acts as a beta-lactamase inhibitor to enhance ampicillin’s efficacy. Gentamicin is added primarily for its synergistic effect with cell wall-active agents against enterococcal infections, improving bactericidal activity.

This treatment strategy aligns with guidelines that recommend using a combination of antibiotics for managing prosthetic valve endocarditis, particularly during the first two months after valve replacement, when the risk of infection is notably increased. The other options may not provide the same broad coverage or synergistic effect necessary for treating endocarditis effectively.