Once-daily topical application of tretinoin 0.05% lotion is an effective treatment for moderate to severe acne vulgaris, with benefits observed slightly more often in women than in men, according to research data published in the Journal of Drugs and Dermatology.
Despite both racial and sex differences in terms of tretinoin’s efficacy, the study suggests that the efficacy of tretinoin is well established and can be helpful for most patients with acne.
The study was a post hoc analysis of 2 multicenter, vehicle-controlled, double-blind phase 3 studies that included 1640 patients (age range, 9-58 years) with moderate to severe acne. Patients were randomly assigned to either tretinoin 0.05% lotion (n=819) or vehicle control (n=821). Both treatments were administered once daily for 12 weeks. The researchers assessed changes in inflammatory and noninflammatory lesions from baseline to week 12. Treatment success, defined by a ≥2-grade reduction in Evaluator’s Global Severity Score and clear/almost clear status, was also assessed. The validated Acne QoL scale was used to evaluate quality of life. Other endpoints included safety, adverse events (AEs) and treatment-related AEs (TRAEs), cutaneous tolerability, and hypo-/hyperpigmentation.
In women and men, the mean percentage reduction in inflammatory lesion counts at week 12 were 56.9% and 53.4%, respectively. Women experienced a significantly greater benefit with tretinoin than men in inflammatory lesion count reduction at week 8 (P =.026) and noninflammatory lesion count reduction at week 12 (51.7% vs 46.1%; P =.035). Conversely, the mean percentage reduction in inflammatory lesion counts in women and men were 47.1% and 39.4%, respectively, with vehicle control.
Despite these differences, treatment success at week 12 was greater in women and men treated with tretinoin 0.05% lotion compared with vehicle (P ≤.001 vs vehicle). Women had a significant advantage over men in regard to treatment success at 12 weeks (P =.013). No significant differences were found between tretinoin and vehicle in black patients or between white male and black patients in regard to reductions in inflammatory lesions (52.1% vs 58.2%; P =.346) or noninflammatory lesion counts (45.9% vs 49.1%; P =.522) or treatment success (15.4% vs 18.0%; P =.668) at 12 weeks.
Treatment with tretinoin was associated with greater patient satisfaction at week 12 (P =.003), and there were also greater improvements in 1 acne quality-of-life domain with active treatment (P =.004). Women had greater TRAEs, including skin dryness (P =.006).
A limitation of the study was the short follow-up duration, reducing the ability to identify even longer-term benefits and adverse effects of tretinoin.
The researchers wrote that the skin dryness at the application site observed at a higher frequency in women “than in males…should be easily managed with appropriate use of moisturizers.”
Lain E, Day D, Harper J, Guenin E. Tretinoin 0.05% Lotion for the once-daily treatment of moderate-to-severe acne vulgaris: impact of gender and race on efficacy and safety. J Drugs Dermatol. 2019;18(11):1128-1138.