Bedaquiline (Sirturo) is a novel anti-TB drug used in MDR/XDR-TB. Its unique mechanism of action targets:

• A Mycobacterial ATP synthase (subunit c of F0F1-ATPase), blocking proton translocation and ATP synthesis ✓
• B InhA (enoyl-ACP reductase) in the mycolic acid synthesis pathway
• C DNA gyrase, preventing supercoil relaxation during replication
• D Arabinosyltransferase (embB), blocking arabinogalactan synthesis

Explanation

Bedaquiline is a diarylquinoline that selectively inhibits mycobacterial ATP synthase by binding to the subunit c of the F0 component, blocking proton translocation across the bacterial membrane. This prevents oxidative phosphorylation in mycobacteria (which are obligate aerobes) and depletes ATP, leading to bactericidal activity against both replicating and non-replicating (dormant) bacilli. This mechanism is distinct from all other standard anti-TB drugs. InhA is targeted by isoniazid/ethionamide; embB by ethambutol; DNA gyrase by fluoroquinolones.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.