Combination topical tretinoin and clindamycin was as effective as combination salicylic acid and clindamycin for reducing lesions in patients with mild to moderate acne, based on data from a 12-week randomized trial.
The findings were published online July 28 in the Journal of the European Academy of Dermatology and Venereology.
Several types of combination treatments allow clinicians to target different causes of acne vulgaris, but the safety and efficacy of tretinoin/clindamycin phosphate and salicylic acid/clindamycin phosphate have not previously been compared, according to Dr. A. Babayeva of Dokuz Eyll University in Izmir, Turkey, and colleagues.
Researchers randomized 46 acne patients aged 18-31 years to one of the two combination therapies: 3% salicylic acid plus clindamycin phosphate 1% lotion (SA/CDP) or all trans retinoic acid 0.05% cream plus clindamycin phosphate 1% lotion (all-TRA/CDP). The average lesion count at baseline was 67 in both groups, and the proportion of inflammatory and noninflammatory lesions was similar between the groups (J. Eur. Acad. Dermatol. Venerol. 2010 July 28 [doi:10.1111/j.1468-3083.2010.03793.x]).
After 12 weeks, the average total lesion count was 13 in the SA/CDP group and 10 in the all-TRA/CDP group; the difference was not statistically significant. The average inflammatory and noninflammatory lesion counts were not significantly different between the two groups (5 vs. 4 and 8 vs. 6, respectively).
After 2 weeks of treatment, significantly more patients in the all-TRA/CDP group showed a 50% reduction in total lesion counts, compared with the SA/CDP group, but there were no significant differences in lesion counts between the groups when patients were assessed after 4, 8, and 12 weeks of treatment, according to the investigators.
All reported side effects were mild to moderate, and most occurred during the first 2 weeks of treatment. The most common reported side effects were dryness, peeling, erythema, burning, and itching. The proportion of patients reporting at least one side effect was similar between the SA/CDP and all-TRA/CDP groups (83% vs. 74%).
Although the efficacy of the all-TRA/CDP was higher in the first 2 weeks, the end results were similar, suggesting SA/CDP can be an effective alternative to all-TRA/CDP, the researchers found. The results support data from previous studies, and they suggest that CDP can help reduce the irritation associated with all-TRA.
The researchers had no financial conflicts to disclose.