Paper II
Question
Chloroquine
Answer
Chloroquine is a 4-aminoquinoline antimalarial, a blood schizonticide.
MOA: chloroquine → accumulates in the parasite’s acidic food vacuole (ion-trapped as a weak base) → inhibits haem polymerase → blocks conversion of toxic free haem into inert haemozoin → toxic free haem accumulates and kills the parasite.
Uses: treatment of P. vivax malaria, chemoprophylaxis, rheumatoid arthritis/SLE (immunomodulatory property).
Adverse effects: retinopathy (irreversible, dose/duration-related), pruritus (notably common in patients of West African descent), QT prolongation at high doses. Widespread resistance has substantially limited use against P. falciparum.

