Background and objectives The alternate day and the intermittent regimens of isotretinoin are efficacious in treating moderate acne vulgaris with low cumulative doses. The former regimen has been found to be superior in comparative studies using weight-based dosing. The fixed dosing of the two regimens has not been explored in a head-to-head trial. The objective was to compare the efficacy and safety of these regimens at fixed dosages in treating grade 2 facial acne vulgaris. Methods It was a randomised, single-blinded, non-inferiority trial. Sixty patients aged 18 years and above with grade 2 facial acne were randomised into two groups: Group A received 20 mg isotretinoin on alternate days, and Group B received 30 mg daily for one week per month for four months. Results The mean acne load in group A and B reduced to 5.63±4.87 and 5.63±4.87 from 22.60±10 and 28.70±18.10, respectively. The percentage of participants achieving a significant response was 96.7% and 93.3% in group A and B ( P= 0.28). The estimates were within the non-inferiority margins. The acne load progressively decreased with greater effect size as the treatment continued. Relapse to pretreatment score was not detected. Side effects were comparable between the groups. The cost was significantly higher with the alternate regimen. Interpretation and conclusions The daily intermittent regimen is non-inferior to alternate day regimen at fixed dosages in significantly improving grade 2 facial acne vulgaris with similar side effect profiles. The daily intermittent regimen, also with a lower cost, is thus preferrable.
Bikash et al. (Sat,) studied this question.