Vancomycin for Staphylococcus aureus endocarditis in intravenous drug users.

Area of Science:

• Infectious Diseases
• Cardiology
• Pharmacology

Background:

• Staphylococcus aureus endocarditis is a serious infection, particularly in intravenous drug users.
• Vancomycin is often used when penicillinase-resistant penicillins are not suitable.
• The clinical efficacy of vancomycin compared to other agents for this condition requires further investigation.

Purpose of the Study:

• To review the clinical outcomes of intravenous drug users with Staphylococcus aureus endocarditis treated with vancomycin.
• To compare the in vitro bactericidal activity of vancomycin and nafcillin against Staphylococcus aureus.

Main Methods:

• Retrospective review of 13 intravenous drug users with Staphylococcus aureus endocarditis treated with vancomycin.
• Analysis of treatment modifications, recurrences, and need for surgery.
• In vitro time-kill studies comparing vancomycin and nafcillin against 10 Staphylococcus aureus isolates.

Main Results:

• Two patients experienced recurrent positive blood cultures after completing vancomycin therapy.
• Two patients required therapy modifications due to persistent bacteremia.
• One patient needed surgery for recurrent fevers, with vegetation showing active infection.
• Vancomycin demonstrated slower bactericidal activity than nafcillin in time-kill studies.

Conclusions:

• Vancomycin treatment for Staphylococcus aureus endocarditis in intravenous drug users may be associated with treatment failures and recurrences.
• Vancomycin appears less rapidly bactericidal than nafcillin in vitro.
• The efficacy of vancomycin as an alternative to penicillinase-resistant penicillins for staphylococcal endocarditis warrants further evaluation.