quinidine


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Related to quinidine: quinine, Quinidine sulfate

quinidine

(kwĭn`ĭdēn'), heart muscle relaxant used to maintain regular heart rhythm patterns. It is an alkaloidalkaloid,
any of a class of organic compounds composed of carbon, hydrogen, nitrogen, and usually oxygen that are often derived from plants. Although the name means alkalilike, some alkaloids do not exhibit alkaline properties.
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 chemically similar to quininequinine
, white crystalline alkaloid with a bitter taste. Before the development of more effective synthetic drugs such as quinacrine, chloroquine, and primaquine, quinine was the specific agent in the treatment of malaria.
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 and, like quinine, occurs naturally in some species of cinchona trees. Quinidine slows the rate of blood flow in heart chambers and lowers the excitability of the muscle. Quinidine is a general relaxant of smooth muscle and acts as a dilator of larger blood vessels. It has also been used to reduce fever and to treat malaria. Synchronized electric shock has largely replaced quinidine as a method of establishing more normal heart rhythms.
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quinidine

[′kwin·ə‚dēn]
(organic chemistry)
C20H24N2O2 A crystalline alkaloid that melts at 174-175°C (345-347°F) and that may be derived from the bark of cinchona; used as the salt in medicine. Also known as β-quinine.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
He remained free from palpitations, fainting, or syncopal episodes over the next fourteen months without quinidine treatment.
The formulation of dextromethorphan and quinidine used in the study already has Food and Drug Administration marketing approval with the brand name Nuedexta for treating pseudobulbar affect (PBA), which can occur in patients with, for example, amyotrophic lateral sclerosis or multiple sclerosis.
The 93 patients randomized to the investigational treatment started on 20 mg dextromethorphan and 10 mg quinidine administered orally once daily for a week, followed by an up-titration schedule over 2 weeks to reach 30 mg dextromethorphan twice daily plus 10 mg quinidine twice daily, the dosage they continued for an additional 7 weeks.
[sup][57] More solid evidence in support of J wave syndromes as repolarization abnormalities is the inhibitory effect of quinidine on both I [sub]Na and I [sub]to .
The quinidine concentrations ranged from 2.06 nM to 500 nM.
The CDC-recommended treatment, parenteral quinidine (given with a second drug: doxycycline, tetracycline, or clindamycin), is the only Federal Drug Administration (FDA)--approved parenteral antimalarial regimen currently available in the United States.
Intravenous (IV) quinine (a 4-quinoline methanol) has been the mainstay of treatment for severe falciparum malaria, although in some countries, including the United States, quinidine, the dextrorotatory diastereoisomer of quinine, is 2 used because of the non-availability of IV quinine .
Though quinidine is the drug of first choice in the management of atrial flutters/fibrillations, a sizeable number of dogs did not responded well to quinidine and therefore were switched to digoxin and most of the dogs responded well except 13 dogs.
Cardiovascular drugs: Amiodarone, Apixaban, Clopidogrel, Dronedarone, Eplerenone, Felodipine, Nifedipine, Quinidine, Rivaroxaban, Ticagrelor
Avanir's NUEDEXTA (dextromethorphan HBr and quinidine sulfate) has been cleared by the US Food and Drug Administration (FDA) for the treatment of pseudobulbar affect.
Among the tanshinones, only dihydrotanshinone significantly inhibited CYP2D6 activity ([IC.sub.50]= 35.4 [micro]M), compared to quinidine, a specific CYP2D6 inhibitor ([IC.sub.50] = 0.9 [micro]M).
In light of these considerations, he was diagnosed as having idiopathic short QT intervals rather than SQTS and has not yet been treated with pharmacological therapy, such as quinidine, or an implantable cardioverter-defibrillator (ICD).