RESUMEN
Despite many years of clinical use of isotretinoin, a comprehensive review of evidence for isotretinoin therapy in patients with acne is lacking. We searched MEDLINE, Embase, Cochrane Central, relevant web pages and bibliographies for randomized controlled trials in acne evaluating isotretinoin vs. control (placebo or other therapy). Data were extracted and summarized descriptively. Eleven trials were identified (total 760 patients randomized), containing mostly men. Mean treatment ages ranged from 18 to 47·9 years and participants generally had moderate-to-severe acne. Across all trials, isotretinoin therapy reduced acne lesion counts by a clinically relevant amount, and always by a greater amount than control, which was either placebo (two studies), oral antibiotics (seven studies) or other control (two studies). Across trials with an overall low risk of bias, two of three demonstrated statistically significant differences between isotretinoin and control. The frequency of adverse events was twice as high with isotretinoin (751 events) than with control (388 events). More than half of all adverse events were dermatological and related to dryness. Adverse events from isotretinoin causing participant withdrawal from trials (12 patients) included Stevens-Johnson syndrome, cheilitis, xerosis, acne flare, photophobia, elevated liver enzymes, decreased appetite, headaches and depressed mood. This review suggests that isotretinoin is effective in reducing acne lesion counts, but adverse events are common. This study was registered with PROSPERO number CRD42015025080.