Antihypeensives act by all of the following mechanism except: March 2012
Ans: A i.e. Na+ K+ ATPase Antihypeensives and mechanism of action Digitalis increases increase force of cardiac contraction (cardiac inotropic) by selectively binding to extracellular face of the membrane associated Na' K' ATPase of myocardial fibres and inhibits it. Digitalis is used in congestive hea failure and cardiac arrhythmias. Prazosin, terazosin, doxazosin, phentolamine and phenoxybenzamine are alpha adrenergic blocking anti-hypeensive drugs. Propranolol, metoprolol, atenolol etc. are some of the beta adrenergic blocking anti-hypeensive drugs Minoxidil and diazoxide are potassium channel openers which were used earlier in severe hypeension and hypeensive emergencies.
Na. ATPase inhibition
Alpha adrenergic blockade
Beta adrenergic blockade
Potassium channel opener