Dapsone

Indications

Dapsone is used for: Pneumonia, Acne, Leprosy, Dermatitis herpetiformis

Adult Dose

Dermatitis Herpetiformis 50 mg PO qDay, titrate to 300 mg qDay or higher to achieve desired effect Reduce dose to minimum effective dose within the range of 50-300 mg qDay as soon as possible Leprosy 100 mg PO qDay, in combination with other antileprosy drugs Tuberculoid or Lepromatous Disease 100 mg PO qDay with rifampin 600 mg PO qDay

Child Dose

Child: PO 2 mg/kg, max 100 mg q24h 4 mg/kg, max 200 mg Once weekly

Renal Dose

Administration

Contra Indications

Hypersensitivity. Severe anaemia, porphyria.

Precautions

G6PD deficiency, methaemoglobin or Hb M. Perform regular blood counts and monitor liver function regularly. Pregnancy and lactation. Lactation: Enters breast milk; not recommended (AAP Committee states "compatible with nursing")

Pregnancy-Lactation

Pregnancy category: C Lactation: Enters breast milk; not recommended (AAP Committee states "compatible with nursing")

Interactions

Decreased serum conc of dapsone when used with rifampicin. Increased plasma conc with probenecid, trimethoprim. Antagonize clofazimine.

Side Effects

Side effects of Dapsone : 1-10% Hemolysis, Methemoglobinemia <1% Reactional states (ie, abrupt changes in clinical activity occurring during any leprosy treatment; classified as reversal of erythema nodosum leprosum reactions), Insomnia, Headache, Exfoliative dermatitis, Photosensitivity, Nausea, Vomiting, Anemia, Leukopenia, Agranulocytosis, Hepatitis, Cholestatic jaundice, Peripheral neuropathy (usually in nonleprosy patients), Blurred vision, Tinnitus, SLE Potentially Fatal: Agranulocytosis, serious cutaneous hypersensitivity reactions, exfoliative dermatitis.

Mode of Action

Dapsone inhibits folic acid synthesis by preventing normal bacterial utilization of PABA (PABA).