Chloroquine and hydroxychloroquine

Chloroquine (CQ; 7-chloro-4[4-diethylamino-1-methlybutylamino]) is a 4-aminoquinoline derivative that has been used extensively for the treatment and prevention of malaria. First synthesized in 1934 by H. Anderson in the Bayer Laboratory in Elberfeld, Germany, it was given the name Resochin and tested against avian malaria and subsequently against human Plasmodium vivax in psychiatric patients in Dusseldorf (Coates, 1963). Despite demonstrated anti-malarial efficacy, it was apparently abandoned after being found “too toxic for practical use in humans.” The compound was rediscovered in the early 1940s through militarily motivated anti-malarial drug research, and in 1946 it was given the name chloroquine and became the drug of choice for malaria worldwide. Although CQ remains effective for non-falciparum malaria in many parts of the world, its use is limited by widespread resistance in Plasmodium falciparum and increasing resistance in P. vivax.