Efficacy of daily low dose versus intermittent isotretinoin regimens in patients with moderate acne vulgaris: A randomized-controlled trial

Abstract

Background: Oral isotretinoin, a vitamin A acid derivative, is the most effective treatment of severe acne. As its use is associated with many side effects, low-dose and intermittent application protocols for patients with mild or moderate acne have been reported. Aim: Our purpose was to compare the outcome of two different regimens of low dose isotretinoin; daily versus monthly doses in patients with moderate acne vulgaris. Patients and methods: A randomized controlled trial was conducted on 75 patients with moderate acne vulgaris attending outpatient clinic in the dermatology department at El-Jumhuriya hospital in Benghazi city during the period of June 2009 to June 2011. The patients were randomly assigned to two groups. Group 1 consisted of 45 patients, treated with a daily fixed dose of 20 mg of isotretinoin and group 2 consisted of 30 patients, treated with 20 mg of isotretinoin twice daily for seven days every month. Both groups were treated for a total period of four months. No topical treatments were permitted for both groups. Clinical assessment was done at 0, 4, 8, 12, and 16 weeks, which included acne lesion counts, total acne load, the assessment of severity score of acne and the side effects of the treatment. Patients were followed for six months after stopping treatment. Results: Fifty five patients with moderate acne vulgaris completed the study. Group 1 consisted of 32 patients with equal proportion of females and males; their mean age and standard deviation (SD) was 20.2±4.1 years. Group 2 consisted of 23 patients; 52.2% were females and 47.8% were males, their mean age and SD was 20±3.4 years. No statistically significant difference was observed according to the age and gender among both groups. Acne scores in each group were significantly lower at the end of treatment period. The mean decrease in the inflammatory and non-inflammatory lesion counts was more and earlier in group 1 compared to group 2, this difference was statistically insignificant. Both treatment regimens were well tolerated; cheilitis was the most frequent side-effect seen in 81.3% and 69.6% of patients in group 1 and group 2 respectively. However, there was no statistically significant differences among both groups regarding the frequency and severity of the side effects. The total cumulative dose was significantly higher in group 1 as compared to group 2 (P=0.000). During the follow- up period there was no statistically significant difference between both groups in relapse rate which has been seen in 7 (21.9%) patients in group 1 and 9 (39.1%) patients in group 2. Conclusion: Both isotretinoin regimens were safe and effective treatment for moderate acne vulgaris, however, intermittent sotretinoin regimen may be a cost- effective alternative.