Effectiveness of Conventional, Low-dose and Intermittent Oral Isotretinoin in the Treatment of Acne: A Randomized, Controlled Comparative study.

Department of Dermatology, Chung-Ang University College of Medicine, Seoul, Korea.
Br J Dermatol. 2010 Nov 29. doi: 10.1111/j.1365-2133.2010.10152.x
Lee JW et al

Abstract

Background:  The efficacy of conventional isotretinoin treatment (0.5 to 1.0 mg/kg per day for 16-32 weeks, reaching a cumulative dose of 120mg/kg) for acne has been well established. To date, there are many reports regarding the efficacy of low-dose and intermittent isotretinoin treatment in acne patients. Data comparing these three therapeutic regimens simultaneously, however, is unavailable.

Objective:  To evaluate the clinical efficacy and tolerability of low-dose and intermittent isotretinoin regimens and directly compare them with conventional isotretinoin treatment. Methods:  In this study, 60 patients with moderate acne were enrolled and randomized to receive either isotretinoin at 0.5 to 0.7 mg/kg/day (group A), isotretinoin at 0.25 to 0.4 mg/kg/day (group B) or isotretinoin at 0.5 to 0.7 mg/kg/day for one week out of every four weeks (group C). The total period of drug administration were 6 weeks in group C, 24 weeks in group A and B. Evaluations included global acne grading system (GAGS) scores, lesion counts (inflammatory and non-inflammatory), patient satisfaction and side effects. A one-year follow-up evaluation after the end of treatment was also performed.

Results:  Differences in GAGS scores were statistically significant between groups A and C (P<0.001) and groups B and C (P=0.014). There was no significant difference between group A and B. For the number of inflammatory lesions, there were statistically significant differences between groups B and C (P=0.040) and groups C and A (P=0.006). There was no significant difference between group A and B. For the number of non-inflammatory lesions, there were statistically significant differences between groups B and C (P=0.046) and groups C and A (P=0.017).

There was no significant difference between group A and B. These results confirm that the conventional and low-dose regimens have similar efficacy. Intermittent treatment had less effect than either conventional or low-dose treatments. Patient satisfaction was highest in group B (3.76), followed by group C (3.31), then A (3.06) with statistically significant differences between groups A and B (P=0.003) and groups B and C (P=0.019) but no significant difference between group A and C. This result suggests that the low-dose regimen is superior to other regimens (conventional or intermittent) in terms of patient satisfaction. Side effects were more frequent with conventional treatment compared to low-dose and intermittent treatments. One year after the end of treatment, 2 of 16 patients relapsed in group A, 3 of 17 patients relapsed in group B, and 9 of 16 patients relapsed in group C.

Conclusion:  Our study suggests that, when considering tolerability, efficacy and patient satisfaction, low-dose treatment is most suitable for patients with moderate acne.