Clofazimine

Key facts

• Clofazimine is an antimicrobial used mainly as part of combination therapy for leprosy (Hansen's disease), and sometimes added to regimens for drug-resistant tuberculosis.
• It builds up slowly in fat and skin over months, which is why its effects, and its trademark skin discolouration, develop and fade gradually, sometimes over months to years after stopping.
• It can prolong the heart's QT interval. Combining it with other QT-prolonging drugs, including bedaquiline, which is often used alongside it for resistant tuberculosis, raises the risk of a dangerous heart rhythm.
• Seek urgent care for an irregular heartbeat, fainting, or severe abdominal pain.

What clofazimine treats

Clofazimine is used within multidrug therapy for leprosy, alongside other antileprosy antibiotics, and as part of combination regimens for certain drug-resistant mycobacterial infections, including some multidrug-resistant tuberculosis regimens.

How clofazimine works

Clofazimine concentrates inside mycobacteria and binds their DNA, disrupting the processes the bacteria need to grow. It also has anti-inflammatory effects that help calm the skin and nerve reactions that can flare up during leprosy treatment.

Before you take it

• Do not take it if you have a known allergy to phenazine compounds.
• Tell your prescriber about any heart rhythm problem or other medicines that prolong the QT interval, especially bedaquiline and other antiarrhythmic drugs, since the combination needs cardiac monitoring.
• Mention any significant digestive disease; at high cumulative doses clofazimine can deposit as crystals in the bowel wall.
• Discuss liver disease and pregnancy or breastfeeding with your prescriber before starting.

Side effects

Common effects include a gradual reddish-brown to black skin, eye and body-fluid discolouration, dry skin, and mild stomach upset.

Stop and seek urgent medical care for any of these:

• An irregular heartbeat or fainting.
• Severe abdominal pain, cramping, or vomiting with no bowel movement.
• Yellowing of the skin or eyes, dark urine, or persistent abdominal pain.

Safety essentials

• Ask about a heart check before starting if you have any cardiac risk factors, and tell your care team about every other medicine you take, since combining clofazimine with other QT-prolonging drugs such as bedaquiline can trigger a dangerous arrhythmia.
• The skin, eye and body-fluid discolouration is expected and reversible over time; it is not itself a reason to stop treatment.
• Report new severe abdominal pain promptly, since very high cumulative doses have been linked to crystal deposits in the bowel.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.