Efficacy and Safety of Micronized Isotretinoin Administered Once Daily Without Food in Patients With Recalcitrant Nodular Acne.

Introduction: Micronized isotretinoin 0.4 to 0.8 mg/kg/day administered in 2 divided doses with or without meals is approved for the treatment of severe nodular acne in patients aged 12 years or older. Although practitioners may suggest once-daily dosing to increase patient compliance, supporting data are limited.

Methods: In this pilot study, patients aged 12 years or older with severe nodular acne (Investigator's Global Assessment [IGA] =>4 and >5 facial nodules) received once-daily micronized isotretinoin 0.4 to 0.8 mg/kg/day without food for 20 weeks. The coprimary efficacy endpoints were changes from baseline in nodular lesion count (NLC) and percentage of patients with a =>90% reduction in NLC at week 24. Secondary endpoints included percentage of patients achieving IGA 0/1; reductions in inflammatory lesion count (ILC) and noninflammatory lesion count (NILC); adverse events (AEs); and severity of erythema, dryness, peeling, oiliness, burning, and pruritus. Analyses included all enrolled patients with the last observation carried forward.

Results: Twenty-two of 24 patients completed the study. From baseline to week 24, NLC decreased by a median (quartile [Q]1, Q3) of 6 (5, 7), all patients experienced complete clearance of nodules, 23/24 (96%) patients achieved IGA 0/1, and ILC and NILC decreased by a mean +/- standard deviation of 97.8% +/- 5.7% and 98.4% +/- 6.2%, respectively (all P<0.0001). There were small, significant, early increases in the severity of erythema, dryness, and peeling; 2 patients experienced 3 AEs considered unrelated to treatment.

Conclusions: Once-daily micronized isotretinoin administered without food was efficacious and well tolerated in patients with severe nodular acne.  J Drugs Dermatol. 2024;23(6):423-428.     doi:10.36849/JDD.7863.