Topical adapalene gel 0.1% vs. isotretinoin gel 0.05% in the treatment of acne vulgaris: a randomized open-label clinical trial

BACKGROUND: Topical application of isotretinoin and adapalene has proved effective in treating acne vulgaris. Both drugs demonstrate therapeutic advantages and less irritancy over tretinoin, the most widely used treatment for acne. They both act as retinoid agonists, but differ in their affinity profile for nuclear and cytosolic retinoic acid receptors. OBJECTIVE: To compare the efficacy and tolerability of adapalene gel 0.1% and isotretinoin gel 0.05% in the treatment of acne vulgaris of the face, in a randomized open-label clinical trial. METHODS: Eighty patients were enrolled and were instructed to apply adapalene gel 0.1% or isotretinoin gel 0.05% once daily over a 12-week treatment period. Efficacy determination included noninflammatory and inflammatory lesion counts by the investigator and global evaluation of improvement. Cutaneous tolerance was assessed by determining erythema, scaling and burning with pruritus. RESULTS: Adapalene and isotretinoin gels were highly effective in treating facial acne. Adapalene gel produced greater reductions in noninflammatory and inflammatory lesion counts than did isotretinoin gel, but differences between treatments were not statistically significant. Adapalene gel was significantly better tolerated than isotretinoin gel during the whole treatment period. CONCLUSIONS: The two gels studied demonstrated comparable efficacy. When adapalene and isotretinoin were compared, significantly lower skin irritation was noted with adapalene, indicating that adapalene may begin a new era of treatment with low-irritant retinoids.