Calcium antagonist

Calcium Antagonists. The potential use of antagonists as radioprotective agents has been suggested based on the importance of... 

Calcium plays a vital role ia excitation—contraction coupling, and failure to maintain iatraceUular calcium homeostasis results ia ceU death. The avaUabUity of the calcium antagonists also provides a powerful tool for basic studies of excitation—contraction coupling, stimulus—excretion coupling, and other specific physiological functions. 

The calcium antagonists interfere with the entry of calcium through the membrane slow calcium channel and therefore prevent intraceUular calcium... 

The cardiac effects of the calcium antagonists, ie, slowed rate (negative chronotropy) and decreased contractile force (negative inotropy), are prominent in isolated cardiac preparations. However, in the intact circulation, these effects may be masked by reflex compensatory adjustments to the hypotension that these agents produce. The negative inotropic activity of the calcium antagonists may be a problem in patients having heart failure, where contractility is already depressed, or in patients on concomitant -adrenoceptor blockers where reflex compensatory mechanisms are reduced. 

The side effects or toxic effects that the calcium antagonists have in common are hypotension, facial flushing, headache, di22iness, weakness, sedation, skin rash, edema, constipation, and abdominal discomfort (nausea, vomiting, and epigastric pressure). 

Preparation of calcium antagonist diltiazem, derivative of 2,3-dihydro-4//-l,4-benzothiazepinone 99YGK394. 

Dihydropyridines not only are intermediates for the synthesis of pyridines, but also are themselves an important class of N-heterocycles an example is the coenzyme NADH. Studies on the function of NADH led to increased interest in the synthesis of dihydropyridines as model compounds. Aryl-substituted dihy-dropyridines have been shown to be physiologically active as calcium antagonists. Some derivatives have found application in the therapy of high blood pressure and angina pectoris. For that reason the synthesis of 1,4-dihydropyridines has been the subject of intensive research and industrial use. The Hantzsch synthesis has thus become an important reaction. 

H. Fujimoto, I. Nishino, K. Ueno and T. Umeda, Determination of the enantiomers of a new 1,4-dihydropyridine calcium antagonist in dog plasma achiral / chiral coupled high performance liquid cliromatography with electrochemical detection , 7. Pharm. Sci. 82 319-322(1993). 

The dihydropyridine-sensitive Cav1.2 calcium channel, that is essential for smooth muscle contration and the target for the calcium channel blocker/calcium antagonists. 

Previous studies by us have led to the discovery of 1-sulfonylindolizines as a new class of potent calcium antagonists (refs 1,3,4 Scheme 2). 

ATC C02DE C08CA03 Use long acting calcium antagonist, antihypertensive, antianginal... 

ATC C02DE C08CA09 Use once-daily calcium antagonist,... 

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