Molecule

Drug Groups

approved

Description

Retapamulin is a topical antibiotic developed by GlaxoSmithKline. It was approved by the United States Food and Drug Administration in April 2007 for the treatment of bacterial skin infections such as impetigo. It is marketed as an ointment under the name brand Altabax.

Indication

For use in adults and pediatric patients aged 9 months and older for the topical treatment of impetigo (up to 100 cm² 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.

Pharmacology

Retapamulin is a semisynthetic pleuromutilin antibiotic. This drug is usually bacteriostatic in action, but may become bactericidal at highed concentrations (when MBC is 1000 times higher than MIC). Retapamulin acts by selectively inhibiting the initiation of protein synthesis in bacteria at the level of bacterial 50S ribosome.

Affected Organisms

Biotransformation

In vitro studies with human liver microsomes demonstrated that retapamulin is extensively metabolized to numerous metabolites, of which the predominant routes of metabolism were mono-oxygenation and N-demethylation. The major enzyme responsible for metabolism of retapamulin in human liver microsomes was cytochrome P450 3A4 (CYP3A4).

Protein Binding

Retapamulin is approximately 94% bound to human plasma proteins, and the protein binding is independent of concentration.

References

External Links