Methemoglobinemia as a Complication of Topical Dapsone Therapy

Although this effect was not observed prior to approval, the drug distributor has now noted the possibility in their reference materials.

Methemoglobinemia and hemolysis are known complications of oral dapsone therapy. The package insert for topical dapsone notes that although hemolysis is a possible side effect of oral dapsone, studies of the topical formulation did not demonstrate any appreciable effect on hemoglobin levels compared with placebo. Methemoglobinemia is a relatively common occurrence in recipients of oral dapsone, but it is usually asymptomatic and rarely requires therapy.

These authors report the case of a single patient who applied topical dapsone as directed and presented within a week to the emergency department for perioral and acral cyanosis accompanied by slight tachycardia and tachypnea. She was found to have a methemoglobin level of 20.3% (normal is <1…

Reviewing Author

Jeffrey P. Callen, MD

Disclosures

Consultant / Advisory board XOMA; Eli Lilly; Celgene

Equity Various trust accounts

Editorial boards JAMA Dermatology; UpToDate

Leadership positions in professional societies Association of Professors of Dermatology (President-Elect)