A randomized, single-blind comparison of topical clindamycin + benzoyl peroxide (Duac®) and erythromycin + zinc acetate (Zineryt®) in the treatment of mild to moderate facial acne vulgaris

Background Antibiotics are often combined with other agents to provide topical acne treatments that are effective against both inflammatory and non‐inflammatory lesions and minimize the development of antibiotic resistance. Objectives To compare the clinical effectiveness of two combination treatments for facial acne: a ready mixed, once daily gel containing clindamycin phosphate (1%) plus benzoyl peroxide (5%) (CDP + BPO) and a twice daily solution of erythromycin (4%) plus zinc acetate (1.2%) (ERY + Zn). Methods/patients In this assessor‐blind, randomized study, 73 patients were treated with CDP + BPO once daily and 75 patients with ERY + Zn twice daily. The treatment period was 12 weeks and lesion counts and global improvement were assessed at weeks 1, 2, 4, 8 and 12. Results CDP + BPO showed an earlier onset of action with a faster significant reduction in total lesion counts than ERY + Zn. The proportion of patients with at least a 30% improvement in non‐inflammatory lesions at week 1 was 31.5% for CDP + BPO and 17.3% for ERY + Zn; the corresponding percentages for inflammatory lesions were 39.7% and 29.3%. A difference was also observed at week 2 (53.4% vs. 36.0% for non‐inflammatory lesions and 72.6% vs. 53.3% for inflammatory lesions). The trend in favour of CDP + BPO, although less marked, continued to the end of the study, with reductions in the total lesion count at endpoint of 69.8% for CDP + BPO group and 64.5% for ERY + Zn group. Both treatments were well tolerated. Conclusions CDP + BPO and ERY + Zn are effective treatments for acne but CDP + BPO has an earlier onset of action that should improve patient compliance.