Pharmacology · Antileprosy drugs
Clofazimine !
A red fat-soluble dye used in leprosy multidrug therapy and in drug-resistant tuberculosis. It turns the skin red-brown and can prolong the QT interval.
Updated 2026-11-01
Also called: CFZ, Cfz
Mechanism of action
Clofazimine is a riminophenazine dye whose action is spread over several targets: it disrupts the mycobacterial membrane, interferes with the electron transport chain, generates hydrogen peroxide and blocks potassium transport. It also has anti-inflammatory effects, useful in leprosy reactions.
- The dye builds up in the mycobacterial membrane
- It disturbs the respiratory chain and produces oxidants
- The bacillus loses energy and dies
Pharmacokinetics
- Absorption
- Incomplete by mouth; fatty meals increase it and antacids lower it
- Distribution
- Very large volume of distribution; it deposits in fat, skin and tissues as crystals
Indications
- Leprosy, multibacillary and paucibacillary, within multidrug therapy Leprosy (Hansen disease) →
- Leprosy reactions, including erythema nodosum leprosum
- Drug-resistant tuberculosis (BDLLfxC and longer regimens) Tuberculosis →
- Nontuberculous mycobacterial infections Nontuberculous mycobacterial infections (MAC, M. abscessus, Buruli ulcer) →
Adverse effects
Common
- Red-brown discoloration of skin, eyes and body fluids
- Dry, scaly skin (ichthyosis)
- Abdominal pain, nausea, diarrhoea
Contraindications
- Hypersensitivity to clofazimine
Key interactions
- Bedaquiline, delamanid and other QT-prolonging drugs
- QT effects add up: ECG monitoring
- Antacids
- Lower clofazimine absorption
- Dapsone
- May blunt clofazimine's anti-inflammatory effect
What is monitored
- ECG, especially with other QT-prolonging drugs
- Persistent or severe abdominal pain
- Skin changes and the person's mood about them
Administration and safety
- By mouth, with food
- In leprosy it comes in WHO multidrug therapy blister packs, free of charge
Nursing care
- Warn before starting that skin, sweat, tears and urine turn red-brown
- Teach to report severe or lasting abdominal pain
- Offer support for the cosmetic change, which can be distressing or stigmatising
- Advise skin moisturisers for dryness
Test yourself
Think of the answer, then tap the question to see it.
Which visible side effect is typical of clofazimine?
Red-brown discoloration of skin and body fluids, often with dry skin.
Why does clofazimine help in leprosy reactions?
Besides killing the bacillus, it has an anti-inflammatory effect.
Which cardiac risk does clofazimine share with bedaquiline?
QT prolongation; together they need ECG monitoring.
Related drugs
Related conditions
- Leprosy (Hansen disease)
- Tuberculosis
- Nontuberculous mycobacterial infections (MAC, M. abscessus, Buruli ulcer)
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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); WHO consolidated guidelines on tuberculosis: module 4: treatment and care (World Health Organization (WHO), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); 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.