What Is It?
Dapsone, a synthetic sulfone with an amino moiety linking two sulfone rings (4,4'-diaminodiphenyl sulfone; molecular weight 248.30), has had medical applications for more than 7 decades for treating various medical conditions including dermatitis herpetiformis, leprosy, and malaria. It has been used in the past for severe recalcitrant acne in doses ranging from 25–50 mg/day.
The primary metabolites of dapsone are N-acetyl dapsone and dapsone hydroxylamine. The most important adverse events of dapsone result from the hydroxylamine metabolite. This compound increases oxidative stress on erythrocytes with resultant potential for dose-dependent hemolysis and methemoglobinemia. Individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency are more susceptible, as the absence of functional G6PD increases the risk of hemolysis and denaturation of hemoglobin.
It was hypothesized that a topical formulation of dapsone may be appropriate for treating acne vulgaris while minimizing systemic exposure and hematologic risk. Accordingly, a topical gel formulation of dapsone 5% was developed by Atrix Laboratories almost a decade ago for the treatment of acne vulgaris. While this product was approved by Health Canada in 2006, it has only recently been marketed in Canada.
Skin Therapy Letter. 2012;17(8):1-3. © 2012 SkinCareGuide.com
