Safe Use of Adapalene 0.1 % Gel in a non-Prescription Environment.

Background: Topical retinoids are the mainstay of acne therapy and, until 2016, were only available by prescription. The margin of safety (MOS) of adapalene for potential teratogenic effects, and its use in pregnancy were investigated as part of the OTC switch.

Objective: To determine MOS using a maximal usage trial (MUsT) and animal embryo-fetal development studies. To conduct a thorough review of safety data with respect to use of Adapalene 0.1% Gel during pregnancy.

Methods: The MUsT was multicenter, open-label pharmacokinetic study which enrolled adolescents and adult subjects with mainly severe acne vulgaris. The no observable adverse event level (NOAEL) for adapalene teratogenicity was established in rat and rabbit embryo-fetal development studies. An exhaustive review of pregnancy data from multiple safety databases was conducted.

Results: The calculated MOS for teratogenicity was 70 for Adapalene 0.1% Gel. For the pregnancy safety review, no pregnancy malformations were attributable to topical adapalene use.

Limitations: Animal studies do not always predict effects in human development. Additionally, safety data is voluntarily reported and intrinsically incomplete.

Conclusion: Adapalene has a large and reassuring MOS making it suitable for OTC use. No teratogenic risk was identified in a MUsT and Pregnancy Safety Review. Adapalene 0.1% Gel is a safe and effective medication for the treatment of acne in a non-prescription environment. Based on available evidence, use of adapalene during pregnancy does not pose harm to the fetus. J Drugs Dermatol. 2021;20(12):1330-1335. doi:10.36849/JDD.6527.