I think dermatologists would agree with the assertions of the Cochrane Review that there is limited evidence according to today’s standards of quality evidence. The Cochrane Review process examines available data, ranking it by the quality of the data. The paper by Costa et al. shows where the Cochrane Review process is fatally flawed. It assumes that, where the highest quality data is lacking, the medication in question must be ineffective or that this at least casts doubt on its efficacy.
Isotretinoin was approved for use in acne in the 1980s. If you look at one initial report by Peck et al. examining the efficacy of isotretinoin versus placebo in patients with very severe nodulocystic acne, the isotretinoin group was so effective that half of the patients in the placebo arm broke code because of a 57% worsening of their acne and went to the treatment arm. Overall, there was a 95% improvement in the isotretinoin-treated group at the end of treatment (J Am Acad Dermatol. 1982 Apr;6[4 Pt 2 Suppl]:735-45). This study truly reflects how effective isotretinoin is in the treatment of severe acne, and any dermatologist who uses isotretinoin knows that for a fact. I suspect that, if someone applied the Cochrane Review process to insulin, they also would question its efficacy.
I agree there are questionable data on high versus standard versus low dosing. For most patients, standard dosing of 1.0 mg/kg per day over 20-24 weeks will result in complete and sustained clearance. There are always outliers, however, and alternative dosing may be needed – either higher cumulative dosing to achieve clearance or longer lower dosing to manage side effects.
The authors clearly have limited experience in treating acne, or the aim of the article was simply a review of available data with no consideration of actual clinical usage. However, if patients see this report, it could undermine dermatologists’ efforts to care for their patients with acne. It is rather irresponsible to publish these types of reviews, in which the efficacy of the medication in question was established long ago and is clearly without question, and it really discredits the integrity of the Cochrane Review.
This report will endure as an example of where bad data can result in bad conclusions.
Andrea L. Zaenglein, MD , is professor of dermatology and pediatric dermatology at Pennsylvania State University, Hershey, Penn., and is a cochair of the American Academy of Dermatology’s most recent acne management guidelines ( J Am Acad Dermatol. 2016 May;74[5]:945-73.e33 ). She reports being a consultant for Sun Pharmaceutical Industries.
