Effectiveness and Tolerability of Low-Dose Micronized Isotretinoin in Patients with Severe Recalcitrant Nodular Facial Acne in India

INTRODUCTIONSevere recalcitrant nodular facial acne is a chronic inflammation with considerable psychosocial impact. Conventional oral isotretinoin is effective, but optimal absorption necessitates dietary compliance. Micronized formulations improve bioavailability and allow flexible dosing. This study evaluated the effectiveness and tolerability of low-dose micronized isotretinoin.

METHODSThis real-world, retrospective, multicenter, observational study analyzed aggregated and anonymized electronic medical records (EMRs) collected over approximately 12 months from patients aged ≥ 12 years with severe recalcitrant nodular facial acne who were treated with low-dose micronized isotretinoin for ≥ 8 weeks. The primary endpoint was improvement in acne severity [in terms of Investigator's Global Assessment (IGA) score] from baseline to 8 ± 2 weeks. Secondary endpoints included improvement at the end of treatment, investigator-graded response, and incidence of adverse events (AEs; serious AEs [SAEs]). Exploratory endpoints assessed patient-graded response and change in nodular/total lesion count.

RESULTSAmong 305 patients (86.89% adults; 13.11% adolescents), 59.67% had an IGA score of 3 and 40.33% had an IGA score of 4 at baseline. Post-treatment, the overall IGA score reduced significantly from 3.40 ± 0.49 at baseline to 2.11 ± 0.79 at 8 ± 2 weeks (37.94% reduction; p < 0.001), 1.30 ± 0.82 at 12 ± 2 weeks (61.76% reduction; p < 0.001), and 0.53 ± 0.73 at 16 ± 2 weeks (84.41% reduction; p < 0.001). By 16 ± 2 weeks, 91.81% patients were graded 'clear'/'almost clear' (IGA score ≤ 1), 67.87% had 'excellent' investigator-graded response, and 65.25% had 'very good' self-graded response. After 16 ± 2 weeks, significant reductions were observed in nodular lesion counts (from 7.06 ± 9.22 to 0.38 ± 1.29; 94.62% reduction; p < 0.001) and total lesions (from 32.25 ± 36.95 to 2.46 ± 4.63; 92.37% reduction; p < 0.001). Six (1.97%) patients experienced AEs; no SAE was observed.

CONCLUSIONIn this real-world EMR-based study, low-dose micronized isotretinoin was found to be clinically effective and well tolerated in patients with severe recalcitrant nodular facial acne, achieving rapid and sustained improvements in lesion counts and acne severity.

TRIAL REGISTRATIONClinical Trials Registry-India, identifier CTRI/2024/07/070813.

Abstract from PubMed