About chloroquine4- aminoquinoline, excellent schizonticide, antimalarial, amebicide, anti inflammatory and local irritant.mechanism of action of chloroquinemalarial parasites digest their own haemoglobin and release highly toxic heme. this heme is used up by parasitic polymerase enzyme and converted to non toxic haemozoin.since chloroquine is a weak base it has high affinity towards acidic lysosome.chloroquine inhibits polymerase enzyme and interfere the formation of haemozoin and results in accumulation of toxic haeme and also it binds with haeme to form haeme- chloroquine complex. these lead to membrane lysis and kill the parasite.