Pharmacologic Substance
quinidine
quin·i·dine [ kwin-i-deen, -din ]
Brand Names:
Nuedexta; Quin-G
Effect:
Cardiac Rhythm Alteration
May Prevent:
Malaria, Falciparum; Tachycardia, Supraventricular; Tachycardia, Ventricular
May Treat:
Atrial Fibrillation;
Atrial Flutter
More Information:
Definitions related to quinidine:
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An alkaloid extracted from the bark of the Cinchona tree with class 1A antiarrhythmic and antimalarial effects. Quinidine stabilizes the neuronal membrane by binding to and inhibiting voltage-gated sodium channels, thereby inhibiting the sodium influx required for the initiation and conduction of impulses resulting in an increase of the threshold for excitation and decreased depolarization during phase 0 of the action potential. In addition, the effective refractory period (ERP), action potential duration (APD), and ERP/APD ratios are increased, resulting in decreased conduction velocity of nerve impulses. Quinidine exerts its antimalarial activity by acting primarily as an intra-erythrocytic schizonticide through association with the heme polymer (hemazoin) in the acidic food vacuole of the parasite thereby preventing further polymerization by heme polymerase enzyme. This results in accumulation of toxic heme and death of the parasite.NCI ThesaurusU.S. National Cancer Institute, 2021
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An optical isomer of quinine, extracted from the bark of the CHINCHONA tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular ACTION POTENTIALS, and decreases automaticity. Quinidine also blocks muscarinic and alpha-adrenergic neurotransmission.NLM Medical Subject HeadingsU.S. National Library of Medicine, 2021
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D isomer of quinine; sometimes used as an antimalarial in patients who cannot tolerate quinine.CRISP ThesaurusNational Institutes of Health, 2006
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Quinidine, drug used in the treatment of abnormal heart rhythms (arrhythmia) and malaria. Obtained from the bark of the Cinchona tree, quinidine shares many of the pharmacological actions of quinine; i.e., both have antimalarial and fever-reducing activity. The main use of quinidine, however...Encyclopedia Britannica, Inc., 2020
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