Dapsone
Dapsone
ALSO — DIAMINODIPHENYL SULFONE
The gentlest thing in this register's acne section, and the smallest effect in it. Its label is the only one anywhere here that reports a drug working differently in women than in men.
The marker is a representative concentration from the cited records. The bar includes approved and compounded preparations recorded here. It is not a recommended dose, a minimum effective strength or a claim that other concentrations are untested. Evidence depends on the vehicle, indication and trial population.
The shaded band is the depth this molecule is understood to reach. Anything below it is out of scope, whatever the label says.
Mechanism
Inhibits neutrophil function and myeloperoxidase activity. The mechanism in acne specifically is not fully established; the effect is anti-inflammatory rather than antimicrobial or comedolytic.
HOUSE NOTES
- Application-site reactions are indistinguishable from the vehicle arm: mild erythema 9% against 9%, mild dryness 14% against 14%.
- The label states that female subjects tended to have greater lesion reductions and greater success than males — a sex difference published without numbers, and the only one in this register.
- The methemoglobinaemia warning names the ancestries in which G6PD deficiency is most prevalent rather than leaving the risk abstract.
- The dosing section carries a futility rule: if there is no improvement after twelve weeks, reassess.
- The manufacturer describes its own gel as gritty with visible drug substance particles.
Layering
- G6PD deficiency
- Congenital or idiopathic methemoglobinaemia
- Other methemoglobin-inducing drugs
- Retinoids
- Benzoyl peroxide