Mefloquine antimalarial actions

ANTIMALARIAL ACTIONS Mefloquine is a highly effective blood schizontocide but has no activity against early hepatic stages and mature gametocytes of P. falciparum or latent tissue forms of P. vivax. The drug may have some sporontoddal activity but is not used clinically for this purpose. 

Mechanism of Action. Although the drug s exact mechanism of action is unknown, mefloquine may exert antimalarial effects similar to chloroquine that is, these drugs inhibit hemoglobin digestion in malarial parasites, thus causing heme by-products to accumulate within the protozoa and cause toxicity and death of this parasite.65... 

Up to the middle of this century quinine (1) was used for the treatment of malaria, and with the widespread development of chloroquine-resistant strains of Plasmodium falciparum it has become important again. Quinine has been used for the treatment of malaria for more than 350 years and has its origin in Peru in the early 17th century. Quinine was the lead structure in the discovery of new synthetic derivatives like mefloquine that have higher antimalarial activity. This section will focus on other new quinoline alkaloids. The mechanism of antiplasmodial action and resistance of quinolines is well described elsewhere [116]. 

Any perturbation of this heme-detoxification process that is unique to Plasmodium is expected to have drastic consequences for the parasite survival. The inhibition of heme aggregation is the targeted action of conventional quinoline based antimalarial drugs such as quinine, chlmnquine and mefloquine. 

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