STEPS

New Drug Reviews

Retapamulin (Altabax) 1% Topical Ointment for the Treatment of Impetigo

barry coutinho, MBBS, University of Pittsburgh Medical Center, Shadyside Family Medicine Residency Program, Pittsburgh, Pennsylvania

Retapamulin (Altabax) 1% ointment is a topical antibiotic labeled for use in adults and children older than nine months for the treatment of impetigo caused by methicillin-susceptible Staphylococcus aureus and Streptococcus pyogenes. It is in a new class of antibiotics called pleuromutilins. Retapamulin has a bacteriostatic mechanism of action similar to that of macrolides and clindamycin (Cleocin).

Safety

Four studies that included a total of 4,775 patients have not shown any serious adverse effects with retapamulin. Coadministration with other topical agents has not been studied. Retapamulin is U.S. Food and Drug Administration (FDA) pregnancy category B; however, safety has not been established in nursing mothers.1

Tolerability

Retapamulin is well tolerated. The most commonly reported adverse effect is pruritus at the application site (1.4 percent).1 Less than 2 percent of patients will report headache, diarrhea, nausea, or nasopharyngitis; less than 1 percent will report application site erythema, pain, or contact dermatitis.1

Effectiveness

Retapamulin is effective in the treatment of impetigo in patients older than nine months. Controlled studies show a clinical success rate of 86 versus 52 percent with placebo (number needed to treat = 3; 95% confidence interval, 2.2 to 4.9).1 A five-day course of retapamulin is equally effective as a 10-day course of oral cephalexin (Keflex) in the treatment of secondarily infected dermatitis2 and traumatic lesions of the skin.3

Retapamulin has not been compared with topical mupirocin (Bactroban) 2% ointment, which is the preferred first-line therapy for impetigo involving a limited body surface area.4 Unlike mupirocin, retapamulin is not approved by the FDA for the eradication of nasal colonization with methicillin-resistant S. aureus. It is not known whether it will be effective in the treatment of extensive impetigo, or impetigo caused by methicillin-resistant or mupirocin-resistant S. aureus.

Price

A 15-g tube of retapamulin will cost approximately $83. This is higher than the cost of a 15-g tube of Bactroban ointment ($46), as well as a 15-g tube of generic mupirocin ($34 to $58).

Simplicity

A thin layer of retapamulin should be applied to the affected area twice daily for five days. The area may be covered with a sterile bandage or gauze dressing. Retapamulin can be used on a total body area up to 100 cm2 in adults or up to 2 percent of the total body surface in children (e.g., approximately 36 cm2 for an average 19 lb, 28-inch nine-month-old infant; 81 cm2 for a 50 lb, 45-inch child). Retapamulin is not for intraoral, ophthalmic, or vaginal use.1

Bottom Line

Retapamulin is an effective alternative to topical mupirocin in the treatment of limited-area impetigo in patients older than nine months. Although it is more expensive, retapamulin does have a dosing advantage over mupirocin; it only requires a twice-a-day application for five days, whereas mupirocin requires application three times a day for 10 to 12 days.

Address correspondence to Barry Coutinho, MBBS, at coutinhobv@upmc.edu. Reprints are not available from the author.

Author disclosure: Nothing to disclose.

REFERENCES

1. Altabax (retapamulin ointment) 1% [Product information]. GlaxoSmithKline April 2007. Accessed August 27, 2007, at: http://us.gsk.com/products/assets/us_altabax.pdf.

2. Parish LC, Jorizzo JL, Breton JJ, Hirman JW, Scangarella NE, Shawar RM, et al. Topical retapamulin ointment (1%, wt/wt) twice daily for 5 days versus oral cephalexin twice daily for 10 days in the treatment of secondarily infected dermatitis: results of a randomized controlled trial. J Am Acad Dermatol 2006;55:1003-13.

3. Free A, Roth E, Dalessandro M, Hiram J, Scangarella N, Shawar R, et al., for the SB275833/030 Study Group. Retapamulin ointment twice daily for 5 days vs. oral cephalexin twice daily for 10 days for empiric treatment of secondarily infected traumatic lesions of the skin. Skinmed 2006;5:224-32.

4. Cole C, Gazewood J. Diagnosis and treatment of impetigo. Am Fam Physician 2007;75:859-64.

STEPS new drug reviews cover Safety, Tolerability, Effectiveness, Price, and Simplicity. Each independent review is provided by authors who have no financial association with the drug manufacturer.

The series coordinator for AFP is Allen F. Shaughnessy, PharmD, Tufts University Family Medicine Residency Program at Cambridge Health Alliance, Malden, Mass.