pulmonary edema fluid in the air sacs and alveoli; the lungs become congested and severe shortness of breath occurs.

Страницы: 1 | 2

• I. MECHANISM OF ACTION
  Calcium movement into cells is mediated by several mechanisms. Albrecht Fleckenstein showed that the calcium channels can be selectively blocked by a class of agents. He called these agents calcium antagonists. Calcium movement into the cells is mediated by several mechanisms. Calcium antagonists act at the plasma membrane to inhibit calcium entry into cells by blocking voltage-dependent calcium channels.
• II. AVAILABLE CALCIUM ANTAGONISTS A. Dihydropyridines
  These agents cause dilation of arteries throughout the body including mild dilatation of coronary arteries. They also cause a variable decrease in myocardial contractility that may lead to heart failure in susceptible individuals.
• IV. NEXT GENERATION AGENTS
  Several dihydropyridine calcium antagonists have been introduced during the past 25 years. First degeneration dihydropyridines are the naturally short-acting agents that include felodipine, isradipine, nifedipine, and nitrendip-ine. These rapid-acting vasodilators are powerful anti-hypertensive agents, but their fast onset of action results in marked vasodilation that causes reflex stimulation of the sympathetic nervous system and hemodynamic adverse effects that include increased heart rate, increased cardiac workload, and an increased incidence of heart failure in patients with left ventricular dysfunction. These adverse effects have become controversial and the short-acting formulations of dihydropyridines such as verapamil and diltiazem are no longer recommended. They have largely been removed from the marketplace.
• BIBLIOGRAPHY
  Khan, M. Gabriel. In Cardiac Drug Therapy, sixth edition, W. B.