DAPSONE

Posology Adults and children over 12 years:

Multibacillary leprosy (3-drug regimen): 100mg daily for at least two years. Paucibacillary leprosy (2-drug regimen): 100mg daily for at least six months. 5mg pyrimethamine.

Dermatitis herpetiformis:

Initially 50mg daily, gradually increased to 300mg daily if required. Once lesions have begun to subside, the dose should be reduced to a minimum as soon as possible, usually 25-50mg daily, which may be continued for a number of years.

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

Pneumocystis carinii pneumonia:

In combination with trimethoprim, 50-100mg daily; 100mg twice weekly or 200mg once weekly.

Children 6-12 years:

Multibacillary leprosy (3-drug regimen): 50mg daily for at least two years. Paucibacillary leprosy (2-drug regimen): 50mg daily for at least six months.

Children under the age of 6 years:

The safety and efficacy of Dapsone in children aged less than six years has not been established. No data are available.

Elderly:

Dosage should be reduced in the elderly where there is an impairment of hepatic function. Method of Administration For oral administration. Tablets should be swallowed whole with a glass of water.

Dapsone should be discontinued, or reduced in dosage, if severe lepra reactions affecting the eyes or nerve trunks occur. The frequencies of undesirable effects are reported according to the following convention: Very common ≥ 1/10 users Rare ≥1/10,000users; <1/1000 users Common ≥1/100users; <1/10 users Very rare <1/10,000 users Uncommon ≥1/1000users; <1/100 users Unknown Cannot be estimated System Organ Class(SOC) Frequency Undesirable effect Haemolysis1 Common Methaemoglobinaemia1 Uncommon Haemolytic anaemia Blood Disorders: Rare Agranulocytosis2 Cardiac Disorders: Uncommon Tachycardia Anorexia Nausea Gastrointestinal Disorders: Uncommon Vomiting General Disorders: Rare Dapsone Syndrome3 Hepatitis Jaundice Hepatic Disorders: Uncommon Changes in liver function tests Metabolic Disorders: Uncommon Hypoalbuminaemia Nervous System Disorders: Uncommon Headache Neuropathy peripheral4 Peripheral motor neuropathy4 InsomniaPsychiatric Disorders: Uncommon Psychoses Skin Disorders: Uncommon Photosensitivity Pruritis Rash Exfoliative dermatitis Maculopapular rash Toxic epidermal necrolysis Rare Stevens – Johnson syndrome Very rare Fixed drug eruptions 1) – these are the most frequently reported adverse effects of dapsone and are dose related; occurring in most subjects administered more than 200 mg daily; doses of up to 100 mg daily do not cause significant haemolysis, but subjects deficient in glucose-6-phosphate dehydrogenase are affected by doses above about 50 mg daily.

2) – this is rare when dapsone is used alone; reports are more common when dapsone has been used with other medicines for malarial prophylaxis. 3) – this may occur following 3 – 6 weeks of therapy; symptoms include rash (always present), fever and eosinophilia.

Id dapsone is not stopped immediately; the syndrome may progress to exfoliative dermatitis, hepatitis, albuminuria, and psychosis. Deaths have been recorded. The majority of patients require steroid therapy for several weeks; this is possibly due to prolonged elimination time of dapsone.

Dapsone should be used with caution in patients with cardiac or pulmonary disease. It is recommended that regular blood counts be performed during treatment with dapsone. Patients deficient in glucose-6-phosphate dehydrogenase, or methaemoglobin reductase, or with haemoglobin M are more susceptible to the haemolytic effects of dapsone.

Dapsone should be used with caution in anaemia. Severe anaemia should be treated before starting Dapsone.

1 • severe anaemia • porphyria • severe glucose-6-phosphate dehydrogenase deficiency. Dapsone contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicine.