retapamulin

Pleuromutilin · Antibiotic (Protein Synthesis Inhibitor) / Anti-infective agent indicated for the topical treatment of impetigo in adults and children. It is a pleuromutilin, a derivative of natural products, with potent activity against gram-positive pathogens (except enterococci), including MRSA and penicillin-resistant S. pneumoniae. It typically exhibits bactericidal activity. The mechanism of action involves inhibiting bacterial protein synthesis by targeting the 50S ribosomal subunit near the A and P sites, resulting in inhibition of peptide bond formation. There is little cross-resistance with other protein synthesis inhibitors. It is available for topical use as a 1% cream, applied twice daily. Systemic absorption is generally low but may be increased in children or when applied to broken skin. It is a substrate of CYP3A4. Resistance is currently rare, primarily due to point mutations reducing drug binding to the ribosome, with upregulated efflux and ribosomal protection proteins also described. Common adverse effects are not explicitly listed but generally related to irritation at the application site. Serious adverse effects are not explicitly listed. Drug interactions are possible due to its CYP3A4 substrate status, and concomitant use with strong inducers or inhibitors should be avoided or used with caution. This monograph provides a comprehensive overview of retapamulin's specific indication, topical application, mechanism, and pharmacokinetic properties, highlighting its role in skin infections and its potential for drug interactions. This monograph summarizes all relevant clinical data from the chapter.