Abstract: Objective To evaluate the efficacy and safety of isotretinoin and viaminate for the treatment of moderate to severe acne vulgaris.Methods A multiple-centre,double-blind,double-analog comparative clinical trial was conducted.Patients diagnosed with moderate to severe acne by GAGS (global acne grading system) were randomly divided into isotretinoin group (10 mg,bid) and viaminate group (50 mg,tid);treatment was done for a total of 6 weeks.All subjects were evaluated before treatment,and at 2,4,6 weeks after the initiation of treatment,for evaluation of lesion count,and for observation of therapeutic effects and side effects.Results A total of 217 patients were enrolled this trial,of which,213 could be evaluated in a FAS (Full Analysis Set) analysis and 200 in a PPS (per protocol) analysis.There was no significant difference in the efficacy at 2,4,6 weeks after the initiation of treatment between the isotretinoin group and viaminate group (6.0% vs 5.0%,29.0% vs 20.0%,57.0% vs 51.0%,respectively).However,the inflammatory papules and pustules decreased more rapidly in the isotretinoin group than in the viaminate group at each of the follow up evaluations (all P<0.05).There was no obvious difference in the rate of clearance of comedones and nodules between the two groups.Both the occurrence rate (68.81% vs 36.53%,P<0.001) and severity (P<0.05) of side effects were higher in the isotretinoin group than in the viaminate group.The main adverse events included mouth dryness,dizziness,etc,occurred more frequently in the isotretinoin group than in the viaminate group.Conclusion For the treatment of moderate to severe acne,the efficacy of isotretinoin is similar to that of viaminate;however,isotretinoin has more immediate effect with more side effects than viaminate.

Key words: Acne vulgaris, Isotretinoin, Viaminate, Randomized controlled trials