Pharmacology · Class
Antileprosy drugs !
Medicines against Mycobacterium leprae. Leprosy is cured with multidrug therapy: rifampicin, dapsone and clofazimine.
Updated 2026-11-01
What they are
WHO multidrug therapy (MDT) combines rifampicin, dapsone and clofazimine for 6 months in paucibacillary leprosy and 12 months in multibacillary leprosy; WHO supplies it free of charge. Colombia has used multidrug therapy since 1985 and its treatment is free. A single dose of rifampicin is also recommended as post-exposure prophylaxis for contacts.
Mechanism of action
Dapsone imitates para-aminobenzoic acid (PABA) and blocks dihydropteroate synthase, so the bacillus cannot make folate. Clofazimine is a fat-soluble dye with several actions (membrane damage, interference with the respiratory chain) and also calms the inflammation of leprosy reactions. Rifampicin blocks bacterial RNA polymerase.
Target: Folate synthesis (dapsone) and mycobacterial membrane and respiratory chain (clofazimine)
Drugs in this class
- DapsoneA sulfone used in leprosy multidrug therapy and dermatitis herpetiformis. It can cause haemolysis, especially in G6PD…Dihydropteroate synthase (folate pathway of mycobacteria)
- ClofazimineA red fat-soluble dye used in leprosy multidrug therapy and in drug-resistant tuberculosis. It turns the skin…Mycobacterial membrane and respiratory chain (several actions)
Others in the class
- Rifampicin (an antituberculosis drug, also part of MDT and of post-exposure prophylaxis)
Test yourself
Think of the answer, then tap the question to see it.
Which three drugs make up WHO multidrug therapy for leprosy?
Rifampicin, dapsone and clofazimine.
Which test is done before starting dapsone, and why?
G6PD activity, because dapsone causes severe haemolysis in G6PD deficiency.
Which antileprosy drug discolours the skin?
Clofazimine (red-brown discoloration).
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Leprosy (World Health Organization (WHO), 2025); Lepra o enfermedad de Hansen (Ministerio de Salud y Protección Social de Colombia, 2024); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 65 (McGraw Hill, 2023).
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Representative model, for educational purposes only.