Retapamulin selectively inhibits bacterial protein synthesis by interacting at a site on the 50S subunit of the bacterial ribosome through an interaction that is different from that of other antibiotics. This binding site involves ribosomal protein L3 and is in the region of the ribosomal P-site and peptidyl transferase center. By virtue of binding to this site, pleuromutilins inhibit peptidyl transfer, block P-site interactions, and prevent the normal formation of active 50S ribosomal subunits. Retapamulin is bacteriostatic against Staphylococcus aureus and Streptococcus pyogenes at the Retapamulin in vitro minimum inhibitory concentration (MIC) for these organisms.

Retapamulin is indicated for use in adults and pediatric patients aged 9 months and older for the topical treatment of impetigo (up to 100 cm 2 in total area in adults or 2% total body surface area in pediatric patients aged 9 months or older) due to Staphylococcus aureus (methicillin-susceptible isolates only) or Streptococcus pyogenes. Safety in patients younger than 9 months has not been established. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Retapamulin and other antibacterial drugs, Retapamulin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

A thin layer of Topibac should be applied to the affected area (up to 100 cm² in total area in adults or 2% total body surface area in pediatric patients aged 9 months or older) twice daily for 5 days. The treated area may be covered with a sterile bandage or gauze dressing if desired.

Contraindicated in patients with hypersensitivity of any ingredient of this preparation.

Adverse effects: Application site irritation (<2% of patients may experience).

Local Irritation: In the event of sensitization or severe local irritation from Retapamulin, usage should be discontinued. Not for Systemic or Mucosal Use: Retapamulin is not intended for ingestion or for oral, intranasal, ophthalmic, or intravaginal use.

Pregnancy & Lactation

Pregnancy Category B. It is not known whether Retapamulin is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Retapamulin is administered to a nursing woman.