DAPSOMED

What it is

DAPSOMED is a medicine containing dapsone. DAPSOMED tablets are available in strengths of 50 mg or 100 mg. Dapsone is a sulfone active against a wide range of bacteria. Its mechanism of action is probably similar to that of the sulfonamides, which involves inhibition of folic acid synthesis in susceptible organisms.

Approved indications

— Dermatitis herpetiformis. — Leprosy. — Actinomycotic mycetoma.

Dosing overview

DAPSOMED should be taken with or after food. In children with leprosy, dosage should be adjusted according to bodyweight.

Key safety warnings

Deaths associated with dapsone have been reported from agranulocytosis, aplastic anaemia and other blood dyscrasias. Complete blood counts should be done frequently in patients receiving dapsone. The FDA Dermatology Advisory Committee recommended that, when feasible, counts should be done weekly for the first month, monthly for six months and semi-annually thereafter. Haemolysis and Heinz body formation may be exaggerated in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, or methaemoglobin reductase deficiency, or haemoglobin M. Dapsone should be given with caution to these patients or if the patient is exposed to other agents or conditions such as infection or diabetic ketosis capable of producing haemolysis. Cutaneous reactions, especially bullous, include exfoliative dermatitis and are probably one of the most serious, though rare, complications of sulfone therapy. Such reactions include toxic erythema, erythema multiforme, toxic epidermal necrolysis, morbilliform and scarlatiniform reactions, urticaria and erythema nodosum. If new or toxic dermatologic reactions occur, sulfone therapy must be promptly discontinued and appropriate therapy instituted. Toxic hepatitis and cholestatic jaundice have been reported early in therapy. Hyperbilirubinaemia may occur more often in G6PD deficient patients. When feasible, baseline and subsequent monitoring of liver function is recommended. If abnormal, dapsone should be discontinued until the source of the abnormality is established. Dapsone has been associated with acute attacks of porphyria and is considered unsafe in porphyric patients.

Contraindications

DAPSOMED is contraindicated in patients with hypersensitivity to dapsone and/or its derivatives.

PBS listing

DAPSOMED 100 mg tablets are listed on the PBS as one item with unrestricted access at an ex-manufacturer price of A$347.82. DAPSOMED 50 mg tablets are listed on the PBS as one item with unrestricted access at an ex-manufacturer price of A$283.44.

Regulatory history

DAPSOMED was first approved on 2 December 2024. Both the 50 mg and 100 mg tablet formulations were registered on the ARTG on 2 December 2024.