Efficacy and side effect profiles of single versus divided doses of isotretinoin in acne vulgaris.

Background: Acne vulgaris is a common skin disorder treated effectively with oral isotretinoin, which can cause significant side effects. This study compares the efficacy and adverse events of single versus divided dosing and evaluates morning versus evening administration.

Methods: This single-center, retrospective cohort study included 60 acne vulgaris patients treated with oral isotretinoin between October 2021 and December 2022. Patients were grouped based on dosing regimen: 30 mg received as a single daily dose and 30 mg received in divided doses (15 mg in the morning, 15 mg in the evening). Laboratory parameters (Alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), creatine kinase (CK), triglyceride (TG), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and total cholesterol) were measured at baseline and 2, 4, and 6 months. Acne severity was assessed using the Global Acne Grading System. Clinical side effects were recorded during follow-up visits.

Results: Both dosing regimens showed similar efficacy, with significant reductions in acne severity. No significant differences were observed in laboratory parameters between the groups. patients on the single-dose regimen experienced a higher incidence of conjunctivitis and facial erythema compared to those on divided doses (p-values 0.01 for both). Morning dose was associated with a significantly higher incidence of ocular side effects than evening dosing.

Conclusion: Divided dosing of isotretinoin preserves efficacy while reducing conjunctivitis and erythema. If a single dose is preferred, evening administration may minimize ocular adverse events. These results support using divided or evening dosing to improve tolerability without compromising treatment outcomes. .