Rifampin: Adjunctive Use in Staphylococcus aureus Infections

• In vitro results of interactions between rifampin and other antibiotics are method dependent and often do not correlate with in vivo findings.
• There are situations in which adjunctive rifampin therapy seems promising, but none in which benefit is definitively established
• Cure rates were often higher in the adjunctive rifampin arms, but studies were typically underpowered to detect differences between groups. However, no study indicated a trend toward worse outcomes with adjunctive rifampin therapy
• rifampin seems beneficial in the treatment of prosthetic device infections and bone infections in human studies and animal models. In other disease states, data are less promising or are not well explored in human investigations
• rifampin therapy may be reasonable in infections in which cure rates are not high, assuming patients are at low risk for toxic effects from rifampin or significant drug-drug interactions (eg, with anticoagulants and immunosuppressive medications).
• In cases in which rifampin treatment may compromise patient safety, the use of this medication is questionable given that the benefit of rifampin remains poorly defined.

Mechanism

• broad-spectrum antimicrobial agent that is bactericidal against S aureus, achieves high intracellular levels and is one of the few antimicrobial agents that can penetrate biofilms and kill organisms in the sessile phase of growth

Dosing

• Its use as monotherapy has been abandoned because of the rapid development of resistance, which is prevented by combination with another active antibiotic.
• Combination therapy with rifampin has been used to treat S aureus infections
• Rifampin doses varied (typically 600-1200 mg/d)
• Adjunctive Antibiotics used in the investigations (in varying dosages), were vancomycin, pefloxacin, ciprofloxacin, oxacillin, fleroxacin, and nafcillin

References:

1. http://archinte.jamanetwork.com/article.aspx?articleid=414583#ArticleInformation