However, the reason for the lower accumulation of chloroquine was unknown. The resistant parasite has now been found to release chloroquine 40 to 50 times more rapidly than the susceptible parasite, although their initial rates of chloroquine accumulation are the same. Hydroxychloroquine sulfate high Plaquenil and arava Chloroquine is a 9-aminoquinoline known since 1934. Apart from its well-known antimalarial effects, the drug has interesting biochemical properties that might be applied against some viral infections. Chloroquine exerts direct antiviral effects, inhibiting pH-dependent steps of the replication of several viruses including members of the flaviviruses, retroviruses, and coronaviruses. Its best. Mechanisms of Drug Action and Resistance Focus on Antimalarials Chemotherapy is the primary means of treating protozoan infections. Successful chemotherapy depends in a large part on the ability to exploit metabolic differences between the pathogen and the host. Recently, an altered chloroquine-transporter protein CG2 of the parasite has been related to chloroquine resistance, but other mechanisms of resistance also appear to be involved. Research on the mechanism of chloroquine and how the parasite has acquired chloroquine resistance is still ongoing, as other mechanisms of resistance are likely. These results suggest that a higher rate of chloroquine release explains the lower chloroquine accumulation, and thus the resistance observed in resistant Plasmodium falciparum. Verapamil and two other calcium channel blockers, as well as vinblastine and daunomycin, each slowed the release and increased the accumulation of chloroquine by resistant (but not susceptible) Plasmodium falciparum. Chloroquine mechanism of resistance Drug Resistance in the Malaria-Endemic World - CDC, Mechanisms of drug action and resistance Hydroxychloroquine plaquenil side effevts Chloroquine Research by German scientists to discover a substitute for quinine led to the synthesis in 1934 of Resochin chloroquine and Sontochin 3-methyl-chloroquine. These compounds belonged to a new class of antimalarials, the four-amino quinolines. History of antimalarials Medicines for Malaria Venture. Chloroquine - Wikipedia. Chloroquine - FDA prescribing information, side effects.. Mechanism of Action Chloroquine, a 4-aminoquinoline, is an anti-protozoal agent. The precise mechanism by which chloroquine exhibits activity is not known. Chloroquine, may exert its effect against Plasmodium species by concentrating in the acid vesicles of the parasite and by inhibiting polymerization of heme. Causes of resistance 12 3.1 Definition of antimalarial drug resistance 12 3.2 Malaria treatment failure 12 3.3 Mechanisms of antimalarial resistance 12 3.3.1 Chloroquine resistance 12 3.3.2 Antifolate combination drugs 13 3.3.3 Atovaquone 13 3.4 Factors contributing to the spread of resistance 13 3.4.1 Biological influences on resistance 13 Resistance to chloroquine has, however, steadily spread since the 1960s from two foci, one in South America and one in South East Asia. Throughout the 1980s, chloroquine resistance spread through Africa, the global heartland of malaria mortality and morbidity, and there are very few effective and affordable drugs to take its place.