Safety of a new micronized formulation of isotretinoin in patients with severe recalcitrant nodular acne: A randomized trial comparing micronized isotretinoin with standard isotretinoin

Background: Isotretinoin is a very effective drug for treating severe recal citrant nodular acne. A now micronized formulation of isotretinoin has been shown to be clinically equivalent to standard isotretinoin with improved b ioavailability and minimal food effect. The safety profile of the micronize d formulation has not been described previously. Objective: The objective of this article is to report the incidence and int ensity of adverse events found in a comparative, double-blind efficacy stud y that showed clinical equivalence of the new micronized formulation of iso tretinoin and the standard isotretinoin formulation (Accutane). Methods: Six hundred patients with severe recalcitrant nodular acne were tr eated with micronized isotretinoin (n = 300) under fasted conditions or sta ndard isotretinoin (n = 300) under fed conditions. One cohort received sing le daily doses of 0.4 mg/kg of micronized isotretinoin without food and the other cohort received 1.0 mg/kg per day of standard isotretinoin in two di vided doses with food. Adverse events were monitored during 20 weeks of dru g therapy. Results: The proportion of adverse events in most body systems was generall y lower in patients receiving micronized isotretinoin than in those receivi ng standard isotretinoin. Conclusion: Micronized isotretinoin appears to have a safety profile simila r to that of standard isotretinoin and to carry a lower risk of mucocutaneo us events and hypertriglyceridemia.