Short-course antibiotic therapy for right-sided endocarditis caused by Staphylococcus aureus in injection drug users

• Right-sided endocarditis caused by Staphylococcus aureus is a frequent complication of injection drug use. Fortunately, the prognosis for this infection when treated with the standard regimen of 4 to 6 weeks of parenteral antistaphylococcal antibiotics is favorable. Nevertheless, in many cases, once drug users feel better, they leave the hospital against medical advice before completing the full course of antibiotic therapy. This problem has stimulated interest in shortening the duration of antibiotic treatment by adding an aminogly-coside antibiotic to a penicillinase-resistant penicillin. Data from in vitro synergy studies and animal models of endocarditis suggest that S. aureus can be eradicated more quickly by combination therapy than by mono-therapy. Reports of three prospective, nonrandomized clinical trials have been published that support the use of a 2-week course of a penicillinase-resistant penicillin and an aminoglycoside antibiotic to treat uncompli-cated, exclusively right-sided endocarditis caused by methicillin-susceptible S. aureus in injection drug us-ers