Isotretinoin use in acne: prospective evaluation of adverse events.

Background: Isotretinoin is an effective treatment for severe acne. Although the spectrum of side effects has been well documented, the changing incidence of such side effects over the course of treatment has not been studied in detail.

Objectives: The purpose of our study was to examine a group of patients monthly over their course of treatment and prospectively document the side effects experienced.

Methods: Over the period between January 1991 and July 1996, 124 courses of treatment with isotretinoin for severe acne were followed. The patients were treated for 4 months at a dose of 1 mg per kg body weight. A questionnaire was administered monthly, inquiring specifically about side effects known to be associated with isotretinoin. Any additional side effects were also noted.

Results: The majority of patients experienced persistent dryness of lips. Dry eyes affected 40% of patients; this continued throughout treatment in 25%. Contact lens wearers were more likely to develop conjunctivitis. Lower back pain was reported early in about 30% of patients and fewer than 10% of patients would develop it later in the course of treatment. Arthralgia was noted in 16.5% of patients at the first visit and there was little change with ongoing treatment. Hair loss was experienced in a small percentage but was rarely noted on more than one occasion. Headaches occurred in less than 10% and were occasionally severe, but most often intermittent and recorded at a single visit. Depression occurred in 4% of patients and tended to persist throughout the treatment. All these patients completed the full course of treatment.

Conclusion: This prospective analysis has shown that patients treated with isotretinoin experienced a predictable series of side effects. Some occurred fleetingly, but several persisted for the duration of treatment.