Clofazimine is a phenazine dye with antibacterial activity similar to that of dapsone. Its mechanism is poorly understood, but its ability to bind to DNA of M. leprae may contribute to its antibacterial activity. There is also some suggestion that the immunomodulatory activity of clofazimine may be useful during reversal reaction. It retains activity in the presence of dapsone resistance. Clofazimine is taken orally once/day, but it is incompletely absorbed in the gastrointestinal tract. Food may increase absorption. The adverse effects are relatively mild, with gastrointestinal symptoms and skin discoloration as the most common. The skin discoloration manifests as increased melanin pigmentation that persists after therapy discontinuation, and there are reports of suicide due to depression from this change. This hyperpigmentation is also associated with sunlight sensitivity, so avoidance of prolonged sun exposure is encouraged. As a dye, the drug can be excreted in urine, sweat, and tears, so those wearing contact lenses should be cautioned.
Clofazimine is no longer commercially available in the United States, but it can be obtained as an investigational new drug through the NHDP. The prescriber is considered to be an investigator and must submit an FDA form 1572 and curriculum vitae to the NHDP. The institutional review board is provided by the Centers for Disease Control and Prevention. Consent forms and other documents will be provided to the prescriber upon request. For more information, visit www.hrsa.gov/hansens/clinical/regimens.htm or call 1-800-642-2477.
Pharmacotherapy. 2012;32(1):27-37. © 2012 Pharmacotherapy Publications