Dapsone

Generic Name: dapsone

Sulfone [EPC]Over-the-Counter (OTC)

Brand Names:

Dapsone

Dapsone (4,4'-diaminodiphenylsulfone, DDS) is a primary treatment for Dermatitis herpetiformis. It is an antibacterial drug for susceptible cases of leprosy. It is a white, odorless crystalline powder, practically insoluble in water and insoluble in fixed and vegetable oils. Dapsone is issued on prescription in tablets of 25 and 100 mg for oral use. It belongs to the sulfone pharmaceutical class.

Overview

Dapsone (4,4'-diaminodiphenylsulfone, DDS) is a primary treatment for Dermatitis herpetiformis. It is an antibacterial drug for susceptible cases of leprosy. It is a white, odorless crystalline powder, practically insoluble in water and insoluble in fixed and vegetable oils. Dapsone is issued on prescription in tablets of 25 and 100 mg for oral use. It belongs to the sulfone pharmaceutical class.

Uses

Dermatitis herpetiformis (D.H.). Leprosy: All forms of leprosy except for cases of proven Dapsone resistance.

Dosage

For Dermatitis herpetiformis, the dosage should be individually titrated starting at 50 mg daily, with corresponding adjustment of a gluten-free diet. Dosages above 200 mg daily are not recommended. For leprosy, Dapsone is used in combination with other anti-leprosy agents as part of multidrug therapy. WHO recommended regimens include Dapsone 100 mg daily with rifampin 600 mg monthly for paucibacillary leprosy (6 months), and Dapsone 100 mg daily with rifampin 600 mg monthly plus clofazimine for multibacillary leprosy (minimum 2 years).

Side Effects

Hematologic effects include dose-related hemolysis, methemoglobinemia, and possible agranulocytosis, aplastic anemia, and other blood dyscrasias. Nervous system effects may include peripheral neuropathy (motor), which is a definite but unusual complication recoverable on drug withdrawal. Skin reactions including toxic epidermal necrolysis, erythema multiforme, and morbilliform/scarlatiniform reactions may occur. Other reactions include nausea, vomiting, abdominal pain, pancreatitis, vertigo, blurred vision, tinnitus, insomnia, fever, headache, psychosis, drug-induced lupus erythematosus, and hepatic effects.

Interactions

Rifampin lowers Dapsone levels 7 to 10 fold by accelerating plasma clearance; in leprosy patients this effect is not considered significant. Folic acid antagonists such as pyrimethamine may increase the likelihood of hematologic reactions. A drug interaction between Dapsone and trimethoprim was noted in HIV-positive patients, where each drug raised the level of the other by approximately 40-50 percent.

Warnings

Agranulocytosis, aplastic anemia, and other blood dyscrasias have been reported. Serious and sometimes fatal cutaneous reactions including toxic erythroderma, erythema multiforme, toxic epidermal necrolysis, and morbilliform/scarlatiniform reactions have occurred. Hemolysis and methemoglobin may be poorly tolerated by patients with severe cardiopulmonary disease. Patients on Dapsone should be monitored with frequent complete blood counts during the first month of therapy, and at regular intervals thereafter. Contraindicated in patients with hypersensitivity to Dapsone or its derivatives.

Pregnancy

Pregnancy Category C. Dapsone has been shown to be embryotoxic in animal studies. There are no adequate and well-controlled studies in pregnant women. Dapsone should be given to a pregnant woman only if clearly needed.

Storage

Store at 20 to 25 degrees C (68 to 77 degrees F). Protect from light. Rx only. Supplied as 25 mg and 100 mg tablets.

Frequently Asked Questions

What is Dapsone used for?

Dermatitis herpetiformis (D.H.). Leprosy: All forms of leprosy except for cases of proven Dapsone resistance.

What are the side effects of Dapsone?

Hematologic effects include dose-related hemolysis, methemoglobinemia, and possible agranulocytosis, aplastic anemia, and other blood dyscrasias. Nervous system effects may include peripheral neuropathy (motor), which is a definite but unusual complication recoverable on drug withdrawal. Skin reactions including toxic epidermal necrolysis, erythema multiforme, and morbilliform/scarlatiniform reactions may occur. Other reactions include nausea, vomiting, abdominal pain, pancreatitis, vertigo, blurred vision, tinnitus, insomnia, fever, headache, psychosis, drug-induced lupus erythematosus, and hepatic effects.

Can I take Dapsone during pregnancy?

Pregnancy Category C. Dapsone has been shown to be embryotoxic in animal studies. There are no adequate and well-controlled studies in pregnant women. Dapsone should be given to a pregnant woman only if clearly needed.

What are the important warnings for Dapsone?

Agranulocytosis, aplastic anemia, and other blood dyscrasias have been reported. Serious and sometimes fatal cutaneous reactions including toxic erythroderma, erythema multiforme, toxic epidermal necrolysis, and morbilliform/scarlatiniform reactions have occurred. Hemolysis and methemoglobin may be poorly tolerated by patients with severe cardiopulmonary disease. Patients on Dapsone should be monitored with frequent complete blood counts during the first month of therapy, and at regular intervals thereafter. Contraindicated in patients with hypersensitivity to Dapsone or its derivatives.

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.