Safety and efficacy of combined use of 4-hydroxyanisole (mequinol) 2%/tretinoin 0.01% solution and sunscreen in solar lentigines.

The objective of this open-label, noncontrolled study was to evaluate the safety of a combination solution containing 4-hydroxyanisole (mequinol) 2%/tretinoin 0.01% (Solagé) with a sunscreen in the treatment of solar lentigines. The study included a total of 406 subjects for a treatment period up to 24 weeks. Efficacy was evaluated clinically by grading the pigmentation level of the treated areas on the face and forearms. A total of 378 subjects were included in the safety population. Of the 173 subjects with skin-related and treatment-related adverse events, severity was reported as mild in 79 subjects, moderate in 71, and severe in 23. Hypopigmentation was observed in 4 subjects and had definitively resolved in 3 of these subjects at the end of the study or after treatment had been discontinued. Halo hypopigmentation was reported in 16 subjects. No allergic reactions were observed. Efficacy evaluation was based on data for 370 subjects. A total of 325 (88%) subjects had facial target lesions almost clear to clear, and a total of 298 (81%) subjects had forearm target lesions almost clear to clear. Our study shows that the mequinol 2%/tretinoin 0.01% solution is effective, convenient, and safe in the treatment of solar lentigines.