Medicines Quinidine

New England Journal of Medicine 344 1304—1313 Grace A A, Camm A J1998 Quinidine. New England Journal of Medicine 338 35-45 Hauptman P J, Kelly R A1999 Digitalis. Circulation 99 1265-1270... 

Nattel S, Ranger S, and Talajic M (1990) Erythromycin-induced long QT syndrome Concordance with quinidine and underlying cellular electrophysiologic mechanism. American Journal of Medicine 89 235-238. 

CARDIAC DEPRESSANTS are little used in medicine, however, some are used to slow the heartbeat in tachycardias and a number of these are often analogues or derivatives of other drugs with optimized activity for this purpose in the heart (e.g. procainamide, quinidine) - these are dealt with under antiarrhythmic agents. 

Gibson, T.P. Nelson, H. A. (1980) Digoxin alters quinidine and quinidine alters digoxin pharmacokinetics in dogs. Journal of Laboratory Clinical Medicine, 95, 417-428. 

Hager, W.D., Fenster, P., Mayersohn, M. et al., (1979) Digoxin-quinidine interaction pharmacokinetic evaluation. New England Journal of Medicine, 300,1238-1241. 

For almost two centuries, the bark was used in medicine as a powder, extract, or infusion. In 1820 Pelletier and Caventou isolated quinine and cinchonine from cinchona, and the use of the alkaloids as such gained favor rapidly. Extensive and classic studies led to elucidation of the structure of quinine (Figure 2) (4) and to its total synthesis in 1944 (5). Cinchona contains 25 closely related alkaloids, of which the most important are quinine, quinidine, cinchonine, and cinchonidine. The average yield of alkaloid is about 6-7 %, of which one-half to two-thirds is quinine. It has been said that quinine owes its dominant position in the treatment of malaria only to the fact that it was the first alkaloid isolated from cinchona, and that there is little among the four major alkaloids to choose from in treating this disease (6). 

Harry Yale (to Brian Hoffman) I would question your statement regarding failure to find another drug as useful as quinidine. There is good clinical evidence that procaine amide is a useful and effective medicine. Furthermore, the development of procaine amide was a logical development based on observations concerning procaine in human arrhythmias. 

Adsorption of low-molecular substances. Of interest also are researches into regularities of adsorption of medicinal substances of HDS because the results of such researches form a scientific basis for development of preparations with a modulated pharmakinetics. A study has been made of adsorption of orthophen, quinidine, scopolamine, amphotericin, and some vitamins on HDS from aqueous solutions [8]. 

Further, a study has been conducted of the release of quinidine (common antiarrhythmic preparation) from various medicinal forms produced by immobilization of quinidine and its complexes with surface active substances or protein on HDS. On the basis of the results of the comparative analysis of the data of biopharmaceutic and pharmacokinetic researches it was inferred that the requirements to medicinal agents of prolonged action are most fully met by the preparation produced by coprecipitation of complexes of quinidine with molecules of serum albumin on the surface of HDS. Administration of this preparation does not give rise to any sharp peak of concentration of quinidine in blood and a slow decrease in concentration during a long term is observed. Besides, administration of this medicinal form makes it possible to provide the maximum bioavailability of quinidine. 

Use activity In medicine as an antihypertensive, tranquilizer, especially as anti-arrhythmic agent the latter activity corresponds to that of the Cinchona alkaloid quinidine by blockade of sodium channels inhibition of glucose uptake in mitochondria of cardiac muscle tissue. A. is poorly resorbable and has a low bioavailability. 

Experiments with animals have revealed that ajmaline (L, Fig. 4) has promising quinidine-like anti-arrhythmic properties and an apparently favourable therapeutic index [1105-1120], but neither the alkaloid itself nor any of its less toxic semi-synthetic derivatives [1121-1129] has gained a firm place in clinical medicine, although ajmaline has seen occasional application in the control of extrasystoles [1130, 1131]. 

Cinchona alkaloids comprising quinine, quinidine, cinchonidine, and cinchonine as the major members constitute a unique class of quinoline alkaloids with tremendous impact on human civilization. The odyssey of Cinchona alkaloids began with the discovery of their antimalarial properties followed by the very successful application in stereochemistry and in asymmetric synthesis. Currently, the portfolio of applications of Cinchona alkaloids is much broader, involving chiral stationary phases for enantioselective chromatography, novel biological activities, and several useful transformation converting them into other modular and chiral building blocks, such as, for example, quincorine or quincoridine. Current pressure on a more intense exploration of sustainable products and easy access to diverse molecular architectures make Cinchona alkaloids of primary importance for synthetic catalytic and medicinal chemistry. 

The cardiological effects of Cinchona bark alkaloids have been recognized in an academic medicine at the end of the seventeenth century. Quinine was used at the beginning, but its pseudoenantiomer quinidine has been found to have more beneficial antiarrhythmic properties, thus becoming a standard medication until newer dmgs were developed in the mid-twentieth century [236]. Quinidine inhibits... 

Cinchona alkaloids are well-known natural products with a fascinating medicinal history and an intriguing molecular structure that is responsible for their use in chemistry [1, 2]. The natural cinchona alkaloids are obtained from the bark extract of the Cinchona tree and consist of quinine, quinidine, cinchonine, and cinchoni-dine with the structures shown in Figure 6.1. 

Quinine 84 and quinidine 85 are well-known medicinally important alkaloids as well as mother structures for organocatalysts. Hatakeyama and co-workers reported on organocatalytic asymmetric synthesis of a key intermediate for these alkaloids. They performed the intramolecular direct aldol reaction of bis aldehyde 79 in the presence of L-proline 57. After reduction of the ketone, syn-diol 80 and anti-diol 81 were obtained with high enantiose-lectivity (Scheme 27.14). The mixture was converted into the common intermediate 83 for quinine 84 and quinidine 85 via ketone 82. Quinine 84 and quinidine 85 were... 

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