Dapsone

These indications are based on manufacturer information for both originator and generic products. For product specific registered indications, please refer to product specific manufacturer information

Registered South African indications:

• All types of leprosy, especially lepromatous and tuberculoid leprosy
• Dermatitis herpetiformis
• Toxoplasmosis and mycetoma (maduromycosis)
• Suppressive action on malarial plasmodia

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Hypersensitivity to sulfonamides or sulfones
• Severe hepatic impairment (Child-Pugh Class C)
• Severe anaemia
• Porphyria
• Severe glucose-6-phosphate dehydrogenase deficiency

Cautions

• Pregnancy
• Breastfeeding
• Moderate hepatic impairment (Child-Pugh Class B)
• Elderly
• Cardiac disease
• Pulmonary disease
• Glucose-6-phosphate dehydrogenase deficiency
• Methaemoglobin reductase deficiency
• Haemoglobin M deficiency
• Anaemia

Forms avail. in SA and covered in this monograph: tab

Dosages below include:

• South African Standard Treatment Guideline recommendations
• International manufacturer recommendations
• South African manufacturer recommendations

Infections caused by: Pneumocystis jirovecii, Mycobacterium leprae, Toxoplasma gondii

Specific doses based on individual indications

Please note that the dosages below should be used in combination with regional guidelines, taking into account local antibiotic sensitivities

South African Standard Treatment Guideline recommendations

P. jirovecii pneumonia - secondary prophylaxis (additional agent required)

• Oral (tab): 100mg, dly; Treatment duration: 21 days
  Refer to pneumocystis pneumonia: STG, Adult 2019

P. jirovecii pneumonia - secondary prophylaxis in co-trimoxazole intolerant patients

• Oral (tab): 100mg, dly; Treatment duration: 6 months
  Refer to pneumocystis pneumonia: STG, Adult 2019

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International manufacturer recommendations

Leprosy (additional agents required)
- Multibacillary leprosy

• Oral (tab): 100mg, dly; Treatment duration: ≥2 years

- Paucibacillary leprosy

• Oral (tab): 100mg, dly; Treatment duration: ≥6 months

Dermatitis herpetiformis

• Oral (tab): Initial: 50mg, dly; Titrate to 300mg, dly; Reduce to lowest effective dose once controlled; Usual maintenance: 25-50mg, dly: Treatment duration: Continue for a number of years

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Once lesions have begun to subside, the dose should be reduced to a minimum as soon as possible. Maintenance dosage can often be reduced in patients receiving a gluten-free diet

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Pneumocystis jirovecii pneumonia (additional agent required)

• Oral (tab): 50-100mg, dly OR 100mg, twice weekly OR 200mg, weekly

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South African manufacturer recommendations

Leprosy (Hansen's disease) (additional agent(s) required)
- Lepromatous leprosy
- Tuberculoid leprosy

• Oral (tab): 50-100mg, dly OR 1.4mg/kg, dly

Dermatitis herpetiformis suppression

• Oral (tab): Initial: 50mg, dly; Titrate to 300mg, dly or more if required; Reduce to lowest effective dose once controlled

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Dose should be reduced to a minimum as soon as possible. 

Maintenance dosage can often be reduced in patients receiving a gluten-­free diet

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Toxoplasmosis and mycetoma (maduromycosis)
Suppressive action on malarial plasmodia

• Oral (tab): Max: 200mg/24hrs (maximum dosage may be attained much more quickly)

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Tablets should be taken with plenty of water

Paed. forms avail. in SA and covered in this monograph: tab

Paed. dosages below include:

• South African Standard Treatment Guideline recommendations
• International manufacturer recommendations
• South African manufacturer recommendations

Infections caused by: Pneumocystis jirovecii, Mycobacterium leprae, Toxoplasma gondii

Specific doses based on individual indications

Please note that the dosages below should be used in combination with regional guidelines, taking into account local antibiotic sensitivities

South African Standard Treatment Guideline recommendations

P. jirovecii pneumonia 
- In patients with sulphonamide allergy

• Oral (tab): 2mg/kg, dly; Max: 100mg/24hrs
  Refer to allergies to sulphonamides: STG, Paed. 2017 

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International manufacturer recommendations

Leprosy (additional agents required)
- Multibacillary leprosy

Younger than 6 years

• Not established for use

Between 6-12 years

• Oral (tab): 50mg, dly; Treatment duration: ≥2 years

Older than 12 years

• See adult dosage

- Paucibacillary leprosy

Younger than 6 years

• Not established for use

Between 6-12 years

• Oral (tab): 50mg, dly; Treatment duration: ≥6 months

Older than 12 years

• See adult dosage

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South African manufacturer recommendations

Leprosy (Hansen's disease) (additional agent(s) required)
- Lepromatous leprosy
- Tuberculoid leprosy

• Oral (tab): 1.4mg/kg, dly

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Dosages must be reduced in children and low­-weight patients

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Dermatitis herpetiformis suppression

• Oral (tab): Initial: 2mg/kg, dly; Titrate until symptoms are adequately controlled; Then: reduce to lowest effective maintenance dose

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Dosages must be reduced in children and low­-weight patients

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Toxoplasmosis and mycetoma (maduromycosis)
Suppressive action on malarial plasmodia

• Oral (tab): Dose should be suitably adjusted to the body mass

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Tablets should be taken with plenty of water

 Pregnancy

• Caution
• It is now generally considered that the benefits of dapsone in the treatment of leprosy outweigh any potential risk to the pregnant patient. Some leprologists recommend 5mg folic acid daily for leprosy patients receiving dapsone during pregnancy

Breastfeeding

• Caution
• Dapsone diffuses into breast milk and there has been a report of haemolytic anaemia in a breastfed infant. While some feel that dapsone should not be used in breastfeeding mothers, in general treatment for leprosy is continued in such patients

Fertility

• There are no data on fertility in humans available

Renal Impairment

• No dose adjustment recommended

Hepatic Impairment

Leprosy
P. jirovecii pneumonia - secondary prophylaxis

• Mild (Child-Pugh Class A): No dose adjustment recommended
• Moderate (Child-Pugh Class B): Caution; dose adjustment recommended
  Reduce dose to 50mg, dly; Avoid co-administration of other hepatotoxic (DILI-potential) agents
• Severe (Child-Pugh Class C): Contraindicated

Elderly

• Caution; no dose adjustment recommended
  Dosage should be reduced in the elderly where there is an impairment of hepatic function

Porphyria Information

• Probably porphyrinogenic (PRP)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Psychosis
• Peripheral neuropathy
  - Peripheral motor neuropathy
• Headache
• Insomnia

Cardiovascular Disorders

• Tachycardia

Gastrointestinal Disorders

• Nausea and vomiting

Hepatobiliary Disorders

• Hepatitis
• Jaundice
• Changes in hepatic function tests

Genitourinary Disorders

• Albuminuria

Endocrine and Metabolic Disorders

• Hypoalbuminaemia
• Anorexia

Skin and Subcutaneous Tissue Disorders

• Rash
• Photosensitivity
• Pruritis
• Maculopapular rash
• Exfoliative dermatitis
• Toxic epidermal necrolysis
• Stevens-Johnson syndrome
• Fixed drug eruptions

Immune, Blood and Lymphatic System Disorders

• Haemolysis
• Methaemoglobinaemia
• Haemolytic anaemia
• Agranulocytosis

Others

• Dapsone syndrome
  - Rash
  - Fever
  - Eosinophilia
  - Exfoliative dermatitis
  - Hepatitis
  - Albuminuria
  - Psychosis

• Probenecid
• Rifampicin
• Trimethoprim
• Oral typhoid vaccine (See additional prescribing points)
• Saquinavir

• Glucose-6-phosphate dehydrogenase levels
• Full blood count
  - Including reticulocyte count
• Hepatic function

Additional observations

• Signs of jaundice, hemolysis, and blood dyscrasias
• Consider alternative methods to monitor diabetes control other than HbA1c

Coadministration with the oral typhoid vaccine

• The oral typhoid vaccine should not be taken until at least three days after finishing a course of dapsone, because the dapsone could make this vaccine less effective

Dapsone's mechanism of action is probably similar to that of the sulfonamides which involves inhibition of folic acid synthesis in susceptible organisms. It is usually considered to be bacteriostatic against M leprae although it may also possess weak bactericidal activity. It is also active against Pneumocystis jirovecii. As with sulfonamides, antibacterial activity is inhibited by p-aminobenzoic acid. In dermatitis herpetiformis, there is local accumulation of polymorphonuclear leukocytes (PMNL). The role of these PMNL cells in the development of inflammation, especially by the respiratory burst of highly toxic oxygen compounds is known. These active substances released against the micro-organisms can cause considerable damage in various tissues such as dermatitis herpetiformis on the skin.

Dapsone also inhibits the cytotoxic extremely active myeloperoxidase hydrogen superoxide-halogen compound and the respiratory burst. Further, an inhibition of the Arthus reaction, the reduction of the response of lymphocytes to phytohemagglutinin, inhibition of complement binding by the alternative route of its activation, inhibition of several lysosomal enzyme systems and inhibition of leukotriene B4 with its specific receptors has been described with dapsone. It also interacts with the reactive oxygen species and may have antioxidant action.

Spectrum of activity: Pneumocystis jirovecii, Mycobacterium leprae, Toxoplasma gondii

Tablet 100mg

• Dapsone (Pharmacare)