FDA Approves Topical Retapamulin for Impetigo

ROCKVILLE, MD, April 13 -- The FDA has given a thumbs up to a topical antibiotic treatment for impetigo in children who are nine months or older.

Retapamulin ointment -- marketed as Altabax by GlaxoSmithKline -- targets susceptible strains of Staphylococcus aureus or Streptococcus pyogenes, the two most common types of bacteria that cause impetigo. The drug is the first in a new class of antibacterial agents called pleuromutilins, which inhibit protein synthesis in bacteria.

To avoid the development of antibiotic resistance, the FDA urged physicians to use retapamulin only where the infection is known or strongly suspected to be caused by bacteria. It is indicated for use twice daily for up to five days.

Retapamulin ointment was approved partly on the basis of a randomized, double-blind, multicenter, placebo-controlled study that enrolled 210 adults and children with impetigo.

Culture-proven pathogens were seen in 82% of patients, and the most common bacteria involved were S. aureus and S. pyogenes. After five days of treatment, 85.6% of those getting retapamulin needed no further antibacterial treatment, compared with 52.1% in the placebo group, GlaxoSmithKline said in a release.

Safety was assessed on the basis of about 2,000 retapamulin-treated adults and children and 1,000 similar patients who received different antibiotics or placebo, the FDA said.

The most common retapamulin-related adverse event was irritation at the site of the application, which occurred in less than 2% of patients.