Dapsone has both anti-infammatory and antimicrobial properties. A combination of these activities may account for its efcacy in acne. Anti-infammatory efects include inhibition of neutrophil myeloperoxidase and eosinophil peroxidase activity, suppression of hypochlorous acid production, scavenging of reactive oxygen species, suppression of neutrophil activity, and inhibition of chemoattractant-induced signal transduction. Antimicrobial activity, similar to that of sulfones and sulfonamides, is by inhibition of bacterial dihydropteroate synthase in the folic acid metabolic pathway. This mechanism is efective against microorganisms synthesizing their own folic acid. In vitro susceptibility testing has demonstrated some activity for Dapsone against Propionibacterium species, including Propionibacterium acnes (P. acnes).

Dapsone is indicated for the topical treatment of acne vulgaris in patients 12 years of age and older.

Those who are hypersensitive to Dapsone.

Most common (incidence ≥ 0.9%) effects are application site dryness and pruritus.

Methemoglobinemia: Cases of methemoglobinemia have been reported. Discontinue Dapsone if signs of methemoglobinemia occur.

Hemolysis: Some patients with Glucose-6-Phosphate Dehydrogenase (G6PD) defciency using topical Dapsone developed laboratory changes suggestive of hemolysis.

Use in Special Populations

Pediatric Use: Safety and efectiveness of Dapsone have not been established in pediatric patients below the age of 12 years.

Geriatric Use: Clinical trials of Dapsone did not include sufcient numbers of subjects aged 65 years and over to determine whether they respond diferently from younger subjects.

Pregnancy & Lactation

Pregnancy Category C. There are no adequate and well controlled studies in pregnant women. Dapsone should be used during pregnancy only if the potential beneft justifes the potential risk to the fetus.

Although systemic absorption of Dapsone following topical application of Dapsone is minimal relative to oral Dapsone administration, it is known that Dapsone is excreted in human milk. Because of the potential for oral Dapsone to cause adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue Dapsone, taking into account the importance of the drug to the mother.