A patient with multibacillary leprosy is started on WHO-recommended multidrug therapy. Which statement about the role of clofazimine in this regimen is CORRECT?
- A Clofazimine is a phenazine dye that binds guanine bases of mycobacterial DNA, inhibiting replication, and also generates reactive oxygen species ✓
- B Clofazimine kills M. leprae by inhibiting dihydropteroate synthase, complementing dapsone
- C Clofazimine acts only as an anti-inflammatory agent and has no direct bactericidal activity
- D Clofazimine inhibits mycobacterial cell wall arabinosyltransferase
Correct answer: A. Clofazimine is a phenazine dye that binds guanine bases of mycobacterial DNA, inhibiting replication, and also generates reactive oxygen species
Explanation
Clofazimine is a riminophenazine dye with both bactericidal and anti-inflammatory properties. It intercalates preferentially at GC-rich regions of mycobacterial DNA, blocking template function and inhibiting RNA synthesis. It also undergoes a redox cycle generating superoxide radicals lethal to M. leprae. Its anti-inflammatory effect (reducing erythema nodosum leprosum) is mediated by inhibition of leukotriene synthesis and impairment of neutrophil migration. Skin pigmentation (reddish-brown discoloration) is its characteristic adverse effect.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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