Clofazimine

How it works

It binds preferentially to mycobacterial DNA and generates reactive oxygen species, producing a slow bactericidal effect, and also has anti-inflammatory properties useful in leprosy reactions.

Prescribing in practice

• Causes dose- and duration-related reddish-brown to black skin and bodily-fluid discolouration that may persist for months to years after stopping; counsel before starting to support adherence.
• Can prolong the QT interval, so caution is needed with other QT-prolonging agents and in electrolyte disturbance.
• Gastrointestinal effects can reflect crystal deposition in the bowel wall, occasionally causing severe abdominal pain or obstruction with prolonged high exposure.

Monitoring

Monitor for gastrointestinal symptoms and skin changes, with ECG review when combined with other QT-prolonging drugs.

Counselling the patient

• Expect a reddish-brown skin tint and discolouration of urine, sweat and tears, which fades slowly after treatment.
• Take with food to reduce stomach upset and improve absorption.
• Report persistent or severe abdominal pain.

Evidence & guidelines

Use is grounded in WHO multidrug therapy recommendations for leprosy and resistant tuberculosis regimens.