Dapsone
Dapsone Medication Information:
Dapsone medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.
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Dapsone 25 mg
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Dapsone 50 mg
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Dapsone 100 mg
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Precautions
Non Lepromatous Lepra Reactions
Complications may include severe peripheral neuritis with accompanying cutaneous sensory loss and paralysis. In the management of acute neuritis corticosteroids may be considered.
Drug Interactions
Rifampicin has been reported to increase the plasma clearance of Dapsone, and probenecid has been reported to increase excretion of Dapsone. Administration of Dapsone with chloroquine and/or primaquine may lead to an increase of methemoglobin levels in individuals predisposed to methemoglobinemia.
Lactation
Dapsone is excreted in breast milk in therapeutic amounts. Sulfones may cause hemolytic anemia in glucose-6-phosphate dehydrogenase deficient neonates.
Lepromatous Lepra Reactions
Complications may include neuritis, an increase in muscle weakness, lymphadenitis, iridocyclitis, orchitis and more rarely nephritis and large-joint arthritis. In the management of these reactions, corticosteroids, and clofazimine may be considered.
Pregnancy
The sulfone drugs are generally contra-indicated in pregnancy and therefore the use of Dapsone during pregnancy should be avoided unless, in the judgement of a physician, potential benefit outweighs the risk. Dapsone in high doses has been reported to be carcinogenic in rats and mice, but negative in salmonella mutagenicity assays. The relevance of this finding to human exposure is unclear.
Reaction States
Leprosy patients receiving effective chemotherapy may suffer episodes of acute or chronic inflammation. Generally, anti-leprosy chemotherapy should be continued unchanged but these reactions must be adequately treated since they may result in crippling deformity.
Supplied
Each round, scored tablet, debossed “100” above and “101” below the score and on the obverse “Jacobus”, contains: dapsone 100 mg. Nonmedicinal ingredients: corn starch, colloidal silicon dioxide, magnesium stearate and microcystalline cellulose. Light, child-resistant bottles of 100. Store at room temperature protected from light.
Contraindications
Sulfones are contraindicated in patients with advanced amyloidosis of the kidneys.
Adverse Effects
Most adverse reactions are dose-related and uncommon at dosages up to 100 mg daily. They include anorexia, nausea, vomiting, headache, dizziness, tachycardia, nervousness, insomnia and skin disorders. Agranulocytosis, peripheral neuritis and psychosis have also been reported. Varying degrees of dose-related hemolysis and methoglobinemia occur in most individuals given more than 200 mg daily. Dosages up to 100 mg daily are unlikely to cause hemolysis, but individuals with glucose-6-dehydrogenase deficiency may be affected by dosages above 50 mg daily. Rare reactions include the “Dapsone syndrome” and hypoalbuminemia.
The “Dapsone syndrome” is hypersensitivity reactions which develop rarely and tend to occur during the first 6 weeks of therapy. Symptoms may include fever, eosinophilia, mononucleosis, lymphadenopathy, leukopenia, jaundice with hepatitis, and exanthematous skin eruptions which may progress to exfoliative dermatitis, toxic epidermal necrolysis, or Stevens-Johnson syndrome. Although patients usually improve if Dapsone is withdrawn fatalities have occurred. Fixed drug eruptions occur in dark-skinned people. Although agranulocytosis has been reported rarely for Dapsone when used alone, reports have been more common when the drug has been used with other agents in the prophylaxis of malaria. Other miscellaneous reactions such as peripheral neuropathy, nephrotic syndrome and renal papillary necrosis have been reported.
Indications
Leprosy, dermatitis herpetiformis, actinomycotic mycetoma.
Dosage
Multibacillary Leprosy
rifampicin 600 mg once-monthly, supervised; dapsone 100 mg daily, self-administered; clofazimine 300 mg once-monthly, supervised and 50 mg daily, self administered.
Paucibacillary Leprosy
rifampicin 600 mg once a month for 6 months, supervised; dapsone 100 mg daily for 6 months, self-administered.
Further information on treatment regimens is contained in “Chemotherapy of Leprosy for Control Programmes” W.H.O. Technical Report Series 675(1982).
Actinomycotic Mycetoma
Adults: Published reports suggest that a dose of 100 mg should be given twice daily and continued for some months after the clinical symptoms have disappeared.
Leprosy
Adults: The standard dose is 100 mg daily (1-2 mg/kg bodyweight).
Children: Dosage should be adjusted according to bodyweight.
The modern treatment of leprosy involves the use of multiple drug regimens to avoid the development of resistant strains. The World Health Organization has made the following recommendations for standard adult treatment regimens (with dosage adjustments according to bodyweight):
Dermatitis Herpetiformis
Adults: The usual maintenance dosage is 50 to 100 mg daily, but as little as 50 mg weekly may be adequate. Dosage of up to 300 mg daily may be considered, but efforts should be made to reduce this to a minimal maintenance dosage as soon as possible.
Overdose
For management of a suspected drug overdose, CPhA recommends that you contact your regional Poison Control Centre. See the eCPS Directories section for a list of Poison Control Centres.
In cases of severe overdosage the stomach should be emptied by aspiration and lavage. There is no specific antidote and therefore treatment should be symptomatic e.g. intravenous methylene blue 1-2 mg/kg bodyweight, intravenous ascorbic acid 0.5-1 g and oxygen for the methemoglobinemia plus general supportive measures. The repeated administration of activated charcoal has been reported to increase the elimination rate of Dapsone and its metabolite following overdosage.
