Partial oral versus full intravenous antibiotic treatment of endocarditis in people who inject drugs: A systematic review

Abstract

Background: Prolonged intravenous (IV) antibiotic therapy may not be optimal for people who inject drugs (PWID) with infective endocarditis (IE) due to unique social and medical needs. The role of partial IV antibiotic therapy with continued oral (PO) antibiotic therapy is unclear. Methods: A systematic review was performed using EMBASE and MEDLINE databases. Included studies compared PO to IV antibiotic treatment for IE in PWID. Results: Four studies met eligibility. Observational studies included full IV treatment groups and partial IV, partial PO treatment groups for severe injection-related infections. PWID with IE comprised 41.0%–64.7% of the study populations but outcomes specific to IE were not separately reported. All-cause 90-day readmission rates were comparable between the IV treatment group (27.9%–31.5%) and partial IV, partial PO treatment group (24.8%–32.5%). Ninety-day mortality was non-significantly different between IV treatment (4.9%–10.7%) and partial IV, partial PO treatment groups (2.4%–13.0%). One small randomized clinical trial compared IV oxacillin or vancomycin with gentamicin to PO ciprofloxacin plus rifampin. The cure rates were 91% and 90%, respectively. Conclusion: There is limited evidence comparing IV treatment to partial IV, partial PO antibiotic treatment in PWID with IE. Observational studies suggest that PO antibiotic therapy after initial IV treatment may be equivalent to full IV treatment alone within specific parameters, but randomized trials are needed to inform recommendations. Substantial clinical and social benefits for PWID and advantages for the health care system will result if PO treatment strategies with equal efficacy can be implemented.