KOLOA, HAWAII — Duac, a clindamycin 1%/benzoyl peroxide 5% topical gel containing moisturizers and humectants, offers advantages for topical acne therapy, Dr. Leon H. Kircik said at the annual Hawaii dermatology seminar, which was sponsored by the Skin Disease Education Foundation.
Amid growing concern about antibiotic resistance, long-term monotherapy with a topical antibiotic is difficult to justify, particularly when convincing evidence shows that adding benzoyl peroxide (BP) greatly reduces the resistance problem.
Moreover, the antibiotic/BP combination acts synergistically and addresses more of the underlying pathologic processes of acne than either agent alone, noted Dr. Kircik, a dermatologist in private practice in Louisville, Ky. “Neither topical erythromycin nor clindamycin alone has as much efficacy as benzoyl peroxide, so why use monotherapy unless the patient is allergic to benzoyl peroxide?” he asked.
BP's downside is that it's inherently drying, which impairs skin barrier function and reduces tolerability. Duac counteracts this by containing dimethicone as an occlusive agent to trap water in the skin as well as glycerin as a humectant to draw water to the stratum corneum from deeper layers.
Dr. Kircik mentioned the results of a 12-week, double-blind, randomized clinical trial presented by Dr. Emil Tanghetti of the University of California, Davis, at last year's annual meeting of the American Academy of Dermatology in New Orleans. In that study, 121 adults with moderate to severe acne received Duac and tazarotene 0.1% cream once daily or tazarotene cream alone.
The median comedo lesion count dropped by 70% at 12 weeks in the combined treatment group, significantly better than the 60% decline in the retinoid monotherapy arm. Papules and pustules declined by 63% with combined treatment, compared with 58% with tazarotene alone. Most impressive of all, Dr. Kircik continued, was the significantly lower incidence of peeling in the combination therapy group at week 4.
Another study led by Dr. Tanghetti involved a head-to-head comparison of Duac and BenzaClin, a competing clindamycin 1%/BP 5% water-based gel that doesn't contain moisturizers. A total of 73% of the 52 participants in the evaluator-blinded, split-face, crossover study rated Duac as significantly better tolerated.
Dr. Kircik is a consultant to Stiefel Laboratories Inc., which markets Duac.
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