Fidaxomicin: a novel macrolide antibiotic for Clostridium difficile infection.

Objective: To review the chemistry, pharmacology, microbiology, pharmacodynamics, pharmacokinetics, clinical efficacy, tolerability, drug interactions, dosing, and administration of fidaxomicin (FDX).

Data Sources: A search of PubMed using the terms "fidaxomicin," "OPT-80," "PAR-101," "OP-1118," "difimicin," "tiacumicin," and "lipiarmycin" was performed. All English-language articles from 1983 to November 2013 were reviewed for relevance. Bibliographies of all articles were reviewed as well as the manufacturer's Web site to further identify relevant information.

Study Selection: All English-language articles from 1983 to November 2013 appearing in these searches were reviewed for relevance to this paper. In addition, their bibliographies were reviewed to identify any articles not identified in the searches.

Data Synthesis: FDX is the first macrolide antibiotic with a narrow spectrum of activity targeted against Clostridium difficile. It is administered orally without regard to food. The primary route of elimination is fecal excretion. Advanced age, hepatic dysfunction, or renal impairment do not alter its disposition. Phase III clinical trials have demonstrated that FDX 200 mg twice daily for 10 days is noninferior to vancomycin 125 mg four times daily for 10 days in the treatment of adults with C. difficile infection and is associated with lower recurrence rates. FDX has a favorable side effect profile and a low potential for drug interactions.

Conclusion: FDX has been shown to be safe and effective in the treatment of adults with C. difficile infection. Further research and pharmacoeconomic studies are needed to clarify and refine its role in the treatment of patients at high risk for recurrence.