Oral isotretinoin: patient selection and management

Oral isotretinoin therapy should now be considered in many patients with moderate acne. The retinoid brings about a significant reduction in the physical and psychological effects of the condition. Oral isotretinoin is recommended in patients with severe acne and moderate acne unresponsive to conventional therapy. Patients with scarring, high sebum excretion rates, severe depression or dysmorphophobia and with some unusual variants, such as acne fulminans, Gram-negative folliculitis and pyoderma faciale, can also benefit. For moderate acne isotretinoin is recommended if there is a less than 50% improvement, or relapse, after 2–3 courses of oral antibiotics. Recent research has shown an increased incidence of resistant strains of propionibacteria. This is often associated with increasing difficulty in management with oral antibiotics. Such patients often require isotretinoin. The cumulative dose of the retinoid seems to be of great importance in the success of the therapy and a dose of some 120 mg/kg appears to produce the best long-term results. This can be achieved by a dosage regimen of 1.0 mg/kg per day for 4 months, or by 0.5 mg/kg per day for a longer period. High doses may be adjusted downward if troublesome side-effects occur, whereas the low dose should be doubled if there is no satisfactory response after 2 months. Side-effects, with the exception of teratogenicity, are dose-dependent and controlled by dose reduction and by local or systemic treatment. Female patients must not be pregnant during treatment or for 4 weeks afterwards. Slow responders may require prolonged treatment. In relapse, a repeat course generally brings a satisfactory response, although some patients may require multiple courses.