Molecule

Drug Groups

approved; investigational

Description

A sulfone active against a wide range of bacteria but mainly employed for its actions against mycobacterium leprae. Its mechanism of action is probably similar to that of the sulfonamides which involves inhibition of folic acid synthesis in susceptible organisms. It is also used with pyrimethamine in the treatment of malaria. (From Martindale, The Extra Pharmacopoeia, 30th ed, p157-8)

Indication

For the treatment and management of leprosy and dermatitis herpetiformis.

Pharmacology

Dapsone is a sulfone with anti-inflammatory immunosuppressive properties as well as antibacterial and antibiotic properties. Dapsone is the principal drug in a multidrug regimen recommended by the World Health Organization for the treatment of leprosy. As an anti-infective agent, it is also used for treating malaria and, recently, for Pneumocystic carinii pneumonia in AIDS patients. Dapsone is absorbed rapidly and nearly completely from the gastrointestinal tract. Dapsone is distributed throughout total body water and is present in all tissues. However, it tends to be retained in skin and muscle and especially in the liver and kidney: traces of the drug are present in these organs up to 3 weeks after therapy cessation.

Toxicity

Overdosage might be expected to produce nasal congestion, syncope, or hallucinations. Measures to support blood pressure should be taken if necessary.

Affected Organisms

Biotransformation

Hepatic, mostly CYP2E1-mediated.

Absorption

Bioavailability is 70 to 80% following oral administration.

Half Life

28 hours (range 10-50 hours)

Protein Binding

70 to 90%

Elimination

Renal

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