Topical retapamulin ointment, 1%, versus sodium fusidate ointment, 2%, for impetigo: a randomized, observer-blinded, noninferiority study.

Background: Retapamulin is a novel pleuromutilin antibacterial developed for topical use.

Objective: To compare the efficacy and safety of retapamulin ointment, 1% (twice daily for 5 days), with sodium fusidate ointment, 2% (3 times daily for 7 days), in impetigo.

Methods: A randomized (2:1 retapamulin to sodium fusidate), observer-blinded, noninferiority, phase III study in 519 adult and pediatric (aged > or = 9 months) subjects.

Results: Retapamulin and sodium fusidate had comparable clinical efficacies (per-protocol population: 99.1 and 94.0%, respectively; difference: 5.1%, 95% confidence interval: 1.1-9.0%, p = 0.003; intent-to-treat population: 94.8 and 90.1%, respectively; difference: 4.7%, 95% confidence interval: -0.4 to 9.7%, p = 0.062). Bacteriological efficacies were similar. Success rates in the small numbers of sodium-fusidate-, methicillin- and mupirocin-resistant Staphylococcus aureus were good for retapamulin (9/9, 8/8 and 6/6, respectively). Both drugs were well tolerated.

Conclusion: Retapamulin is a highly effective and convenient new treatment option for impetigo, with efficacy against isolates resistant to existing therapies.