Clindamycin phospate-zinc acetate versus clindamycin phosphate-zinc acetate + adapalene in the treatment of mild to moderate acne. Results of a multicentre, randomized, retrospective, sponsor-free study

Introduction: The aim of the present study was to evaluate the efficacy and the response in patients with mild to moderate acne of a clindamycin phosphate-zinc acetate topical therapy in comparison with clindamycin phosphate-zinc acetate plus adapalene. Methods: Patients with mild to moderate acne were randomized into two groups and treated, respectively, with a gel containing 1 % clindamycin phosphate-0.5% zinc acetate (2 applications/day for 12 weeks) or with the same gel (1 application/day for 12 weeks) plus a gel containing 0.1% adapalene (1 application/day for 12 weeks). No other topical or systemic drugs were allowed, except for a detergent and a sunscreen. Acne severity and treatment efficacy were evaluated by means of the Global Acne Grading System (GAGS). Results: At the end of the study, 63 patients were considered evaluable (29 patients in the group treated with clindamycin-zinc and 34 in the group treated with clindamycin-zinc and adapalene). Significant clinical improvement (maggiore/uguale 50% from baseline) was observed in 12/29 patients (41.4%) in the group treated with clindamycin-zinc and in 22/34 patients (64.7%) in the group treated with clindamycin-zinc and adapalene (p< 0.05). Irritant contact dermatitis was observed in 12 patients (3 in the group treated with clindamycin-zinc and 9 in the group treated with clindamycin-zinc and adapalene); in the latter group, two patients stopped the treatment. Conclusions: On the basis of the results of this study, which is the first one on the activity and tolerability of the association clindamycin-zinc, the latter association is less effective than the association clindamycin-zinc and adapalene.