A leprosy patient on WHO multidrug therapy develops acute haemolytic anaemia and methaemoglobinaemia. The drug most likely responsible is:

• A Rifampicin
• B Clofazimine
• C Ofloxacin
• D Dapsone ✓

Explanation

Dapsone (a sulfone) is a key anti-leprosy drug but dose-dependently causes haemolytic anaemia (due to oxidative stress on RBCs, particularly in G6PD-deficient patients) and methaemoglobinaemia (due to oxidation of haemoglobin iron from Fe2+ to Fe3+). These haematological adverse effects are the most significant toxicities of dapsone and are predictable. Rifampicin causes hepatotoxicity and reddish discolouration of secretions; clofazimine causes skin discolouration (slate-grey/brown).

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.