Toxicity of Low-Dose Intermittent Isotretinoin in Recalcitrant Acne

Isotretinoin, an oral retinoid, has been utilized to achieve long term remissions in cases of recalcitrant acne. In the conventional dosage schedule, the use of oral isotretinoin has been limited by the occurrence of biochemical abnormalities such as hypertriglyceridaemia and impaired liver function tests and radiological changes consistent with diffuse idiopathic skeletal hyperostosis. Low-dose intermittent regimen of oral isotretinoin has been evolved as a cost effective alternative to the conventional dosage regimen in cases of acne. This study addresses the issue of adverse effects of low-dose intermittent isotretinoin and the safety of this regimen.

A total of 60 cases of recalcitrant acne were included in the study. Baseline haematological, biochemical and radiological investigations were carried out. Low-dose intermittent isotretinoin was instituted in a dose of 0.5 mg/kg/day for one week in every four weeks for six months. The investigations were repeated at the end of six months therapy.

High triglyceride levels occurred in 5% of cases whereas impaired liver function tests and skeletal hyperostosis of the spine were not observed in any case after low-dose intermittent isotretinoin.

The low-dose intermittent regimen in cases of acne may be utilized to limit the systemic toxicity of oral isotretinoin.