Quinine is the principal alkaloid derived from the bark of cinchona tree. The benefits of cinchona bark were first recognized in 1630 in South America. Quinine was isolated from cinchona bark in 1820 and is still obtained from the natural source. Quinine is the levorotatory isomer of quinidine, a more potent, but more toxic, antimalarial. Quinine is a rapidly acting antimalarial agent. It suppresses the asexual erythrocytic forms of al malarial parasites and has a slight effect on the gametocytes of Plasmodium vivax and Plasmodium malariae but none on those of Plasmodium faciparum. It has been used in malaria suppression and treatment for more than 300 years. Although superseded by other antimalarial drugs, following the development of widespread resistance to chloroquine and other drugs, it has again become an important antimalarial drug. It also has analgesic, antipyretic, mild oxtocic, cardiac depressant and sclerosing properties. Quinine was approved by the FDA in 1939.
Effects
The severe or irreversible adverse effects of Quinine, which give rise to further complications include Thrombocytopenia, Agranulocytosis, Angina, Ventricular fibrillation, Pancytopenia, Hypoprothorombinemia, Ventricular arrhythmia, Leukopenia, Bronchoconstriction.Quinine produces potentially life-threatening effects which include Hemolytic anemia, Sinus arrest, Junctional rhythms, AV block, Hemolytic uremic syndrome. which are responsible for the discontinuation of Quinine therapy.The signs and symptoms that are produced after the acute overdosage of Quinine include Hypotension, Coma, Seizures, Blurred vision, Respiratory depression, Hypoglycemia, Respiratory depression, Heart block, Visual distrubances, Sinus tachycardia, Blindness, Optic nerve blindness, Lesions of auditory nerve, Contracted visual fields, Central scotoma, Abnormal color vision.The symptomatic adverse reactions produced by Quinine are more or less tolerable and if they become severe, they can be treated symptomatically, these include Headache, Nausea, Vomiting, Fever, Tinnitus, Abdominal pain, Visual disorders, Maculopapular rash, Confusion, Pruritus, Erythema, Photosensitivity, Diplopia, Syncope, Night blindness, Photophobia, Wheezing, Cinchonism.