Anantianginal is adrug used in the treatment ofangina pectoris, a symptom ofischaemic heart disease.
Drugs used arenitrates,beta blockers, orcalcium channel blockers.
Nitrates causevasodilation[1] of the venous capacitance vessels by stimulating theendothelium-derived relaxing factor (EDRF). Used to relieve both exertional and vasospastic angina by allowing venous pooling, reducing the pressure in the ventricles and so reducing wall tension and oxygen requirements in, the heart. Short-acting nitrates are used to abort angina attacks that have occurred, while longer-acting nitrates are used in the prophylactic management of the condition.
Agents includeglyceryl trinitrate (GTN),pentaerythritol tetranitrate,isosorbide dinitrate andisosorbide mononitrate.
Beta blockers are used in the prophylaxis[2] of exertional angina by reducing the myocardial oxygen demand below the level that would provoke an angina attack.
They are contraindicated invariant angina and can precipitateheart failure. They are also contraindicated in severe asthmatics due to bronchoconstriction, and should be used cautiously in diabetics as they can mask symptoms ofhypoglycemia.
Agents include either cardioselectives such asacebutolol ormetoprolol, or non-cardioselectives such asoxprenolol orsotalol.
Calciumion (Ca++) antagonists (Calcium channel blockers) are used in the treatment of chronic stable angina, and most effectively in the treatment ofvariant angina (directly preventing coronary artery vasospasm). They are not used in the treatment of unstable angina .
In vitro, they dilate the coronary and peripheral arteries and have negativeinotropic andchronotropic effects - decreasingafterload, improving myocardial efficiency, reducingheart rate and improving coronary blood flow.In vivo, the vasodilation andhypotension trigger thebaroreceptor reflex. Therefore, the net effect is the interplay of direct and reflex actions.
Examples include Class I agents (e.g.,verapamil), Class II agents (e.g.,amlodipine,[3]nifedipine), or the Class III agentdiltiazem.
Nifedipine is more a potent vasodilator and more effective in angina. It is in the class ofdihydropyridines and does not affect refractory period on SA node conduction.
Exertional Angina: In patients with exertional angina, NORVASC reduces the total peripheral resistance (afterload) against which the heart works and reduces the rate pressure product, and thus myocardial oxygen demand, at any given level of exercise.
