Chloroquine has been extensively used in mass drug administrations, which may have contributed to the emergence and spread of resistance. It is recommended to check if chloroquine is still effective in the region prior to using it. What is hydroxychloroquine for How long does chloroquine take to work Chloroquine is one of the oldest anti-malarial agent, effectively used in malarial infections. P. falciparum and vivax are the sensitive types. It is a rapidly acting drug, targeting the asexual stage. It is an effective blood schizonticidal agent. It is gametocidal, except for P. falciparum. The drug chloroquine is bactericidal for Bacillus megaterium ; it inhibits DNA and RNA biosynthesis and produces rapid degradation of ribosomes and dissimilation of ribosomal RNA. Inhibition of protein synthesis is also observed, evidently as a secondary effect. Inhibition of DNA replication is proposed as a general mechanism of the antimicrobial action of chloroquine. General antimicrobial mechanism of action of chloroquine. Chloroquine accumulates in very high concentrations in the parasite food vacuole Geary et al. 1986. Once in the food vacuole, chloroquine is thought to inhibit the detoxification of heme. Chloroquine becomes protonated to CQ 2+ because the digestive vacuole is acidic pH 4.7 The Centers for Disease Control and Prevention recommend against treatment of malaria with chloroquine alone due to more effective combinations. In areas where resistance is present, other antimalarials, such as mefloquine or atovaquone, may be used instead. What is the mechanism of action of chloroquine and primaquine Mechanisms of drug action and resistance, Chloroquine Mode of Action Science Is plaquenil used to treat ms Cautions. Since anemia, methemoglobinemia, and leukopenia may occur following administration of large doses of primaquine, do not exceed adult dosage of 1 tablet = 15 mg base daily for fourteen days; make routine blood examinations particularly blood cell counts and hemoglobin determinations during therapy; drug should be discontinued immediately. Primaquine dosing, indications, interactions, adverse.. Antimalarial drugs Mode of action and status of resistance. Antimalarial Drugs — Quinine, Quinidine, Sulfonamides, Chloroquine and More. In this study we investigated the effects of primaquine and chloroquine on oxidative damage and DNA damage in brain, liver and kidney of rats after 7, 14 and 21 days of administration. Chloroquine is thought to exert its antimalarial effect by preventing the polymerization of toxic heme released during proteolysis of hemoglobin in the Plasmodium digestive vacuole. The mechanism of this blockade has not been established. We incubated cultured parasites with subinhibitory doses of 3Hchloroquine and 3H quinidine. Primaquine is the essential co-drug with chloroquine in treating all cases of malaria. It is highly effective against the gametocytes of all plasmodia and thereby prevents spread of the disease to the mosquito from the patient.