WHO Model Prescribing Information: Drugs Used in Leprosy
(1998; 28 pages) View the PDF document
Table of Contents
View the documentPreface
View the documentIntroduction
View the documentDiagnosis of leprosy
View the documentClassification of leprosy
View the documentTreatment of leprosy
View the documentTreatment of lepra reactions
View the documentTreatment of neuritis
View the documentTreatment of eye complications
View the documentManagement of nerve damage
View the documentTreatment of leprosy during pregnancy and lactation
View the documentTreatment of patient with concomitant active tuberculosis
View the documentTreatment of patients with concomitant HIV infection
Open this folder and view contentsTreatment of leprosy in special situations
Close this folderDrug data sheets
View the documentClofazimine
View the documentDapsone
View the documentMinocycline
View the documentOfloxacin
View the documentPrednisolone
View the documentRifampicin


Group: antileprosy agent
Tablet: 25 mg, 50 mg, 100 mg

General information

A sulfone that remains of prime importance in the treatment of leprosy. Dapsone is both bacteriostatic and weakly bactericidal against M. leprae, the minimum inhibitory concentration for fully sensitive organisms being approximately 0.003 micrograms/ml. However, resistant strains can develop de novo during prolonged treatment with dapsone alone, and their incidence is increasing in previously untreated patients. In some areas the prevalence of primary resistance is currently estimated to be as high as 40%.

After absorption from the gastrointestinal tract, dapsone is distributed widely in body tissues and it is subsequently retained selectively in skin, muscle, liver and kidneys. It is partially acetylated or conjugated in the liver and ultimately excreted in the urine as metabolites. A dose of 100 mg produces a peak serum concentration of approximately 2 micrograms/ml, which declines with a half-life of 1-2 days.

Clinical information

Uses: Paucibacillary and multibacillary leprosy in combination with other antileprosy drugs.


Paucibacillary leprosy (in combination with rifampicin)

Adults: 100 mg daily for 6 months.

Children (10-14 years): 50 mg daily for 6 months

Children, less than 10 years: Adjust the dose. For example, dapsone, 25 mg daily for 6 months

Multibacillary leprosy (in combination with rifampicin and clofazimine)

Adults: 100 mg daily for 12 months

Children (10-14 years): 50 mg daily for 12 months

Children, less than 10 years: Adjust the dose. For example, dapsone, 25 mg daily for 12 months

Contraindications: Known hypersensitivity to sulfones; severe anaemia.

Precautions: Pre-existing severe anaemia should be treated before dapsone therapy is started. Dapsone can induce haemolysis of varying degree, particularly in patients with glucose-6-phosphate dehydrogenase deficiency, and dose-dependent methaemoglobinaemia may supervene during the second week treatment. The clinical response and blood count must therefore be closely monitored in susceptible patients during the first weeks of treatment. Dapsone therapy should not be discontinued if exacerbations occur.

Adverse effects: Dapsone is generally well tolerated at recommended dosages, but symptoms of gastrointestinal irritation occasionally occur. Other less common reactions include headache, nervousness and insomnia.

Blurred vision, paraesthesia, reversible neuropathy, drug fever, skin rashes, and psychoses have also been reported. Hepatitis, Herxheimer reactions and agranulocytosis may rarely occur.

Drug interactions: Concurrent administration of clofazimine to leprosy patients receiving rifampicin with dapsone may decrease the rate of absorption of rifampicin and increase the time to peak plasma level.

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