title: Isotretinoin 5 mg daily for low-grade adult acne vulgaris--a placebo-controlled, randomized double-blind study.
abstract: BACKGROUND
  Despite acne persisting into adulthood in up to 50% of the population, very few therapeutic studies have been performed in this age group.
  
  
  OBJECTIVE
  To assess the efficacy of 5 mg/day isotretinoin in adult acne.
  
  
  METHODS
  An investigator initiated, industry-sponsored, randomized, double-blind, placebo-controlled, parallel-group clinical study of isotretinoin 5 mg/day in the treatment of low-grade adult acne for 16 weeks followed by an open-label phase of 16 weeks. Group 1 received 32 weeks of 5 mg isotretinoin/day; Group 2 first received 16 weeks of placebo, followed by 16 weeks open-label 5 mg isotretinoin/day. Patients were followed for a further 10 weeks off treatment. The primary end-point was the difference in acne lesion count and disability score after 16 weeks isotretinoin compared to placebo. Secondary end-points included differences in these counts/scores after 32 weeks of isotretinoin compared to baseline, and after 10 weeks off treatment, compared to end of treatment (week 32).
  
  
  RESULTS
  There were highly significant differences (P < 0.0001) in acne lesion count, Dermatology Life Quality Index and self-assessment after 16 weeks of isotretinoin, compared to placebo (both per protocol and intention to treat). Acne lesions fell significantly, within 4 weeks of 5 mg isotretinoin/day (Group 1) and continued to fall during 32 weeks of treatment [acne lesion count (mean ± SD): 11.3 ± 8.1 (baseline), 3.6 ± 5.5 (week 16), 1.3 ± 3.1 (week 32), P < 0.0001)]. There was a similar significant reduction in acne lesion count in Group 2, but only from week 20, 4 weeks after starting open-label 5 mg isotretinoin. Adverse effects were minimal.
  
  
  CONCLUSIONS
  Isotretinoin 5 mg/day is effective in reducing the number of acne lesions, and improving patients dermatologic quality of life, with minimal adverse effects.
authors.affiliation: Dermatology Department, Waikato Hospital, Hamilton, New Zealand.
authors.forename: M
authors.initials: M
authors.lastname: Rademaker
authors.forename: J M
authors.initials: JM
authors.lastname: Wishart
authors.forename: N M
authors.initials: NM
authors.lastname: Birchall
mesh_terms: D000152:Acne Vulgaris / Q000188:drug therapy*; D000328:Adult; D003879:Dermatologic Agents / Q000008:administration & dosage*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D015474:Isotretinoin / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D012720:Severity of Illness Index
chemical_list: D003879:Dermatologic Agents; D010919:Placebos; D015474:Isotretinoin