Class II antiarrhythmic agents

Class II Antiarrhythmic Agents The p-Adrenoceptor Blocking Agents... 

Propranolol. Propranolol (Table 1), a Class II antiarrhythmic agent, is usefiil in the management of hypertrophic subaortic stenosis, especially for the treatment of exertional or other stress-induced angina by improving blood flow. The dmg can increase exercise tolerance in patients suffering from angina. Propranolol has been shown to have cardioprotective action in post-MI patients (37—39,98,99,108). 

Metoprolol. Metoprolol tartrate (Table 1), also a Class II antiarrhythmic agent, is a HpophiHc, cardioselective P -adrenoceptor blocking agent... 

Other P"Adrenoceptor Blocking Agents. Carteolol hydrochloride (Table 1) is also a Class II antiarrhythmic agent. In three separate studies in patients having angina pectoris, carteolol was considered effective as evidenced by a reduction in the frequency and severity of anginal episodes, reduction in the amount of nitroglycerin consumed, improvement of ECG parameters, or an increase in the duration of trea dmill exercise (42). 

The p adrenoceptor antagonists (beta blockers) are class II antiarrhythmic agents. They prolong phase 4 of the cardiac action potential (pacemaker potential), slowing the heart rate. There are three subtypes of P adrenoceptors Pi, P2 and P3. Stimulation of Pi adrenoceptors in the heart increases the force and rate of cardiac contraction, as well as increasing automaticity of the pacemaker sites and conduction through the AV node. The P2... 

Class III antiarrhythmic agent with additional classes I, II, III, and IV actions. Prolongs action potential duration and effective refractory period in all cardiac tissues,... 

Dolasetron Hypersensitivity to the drug or components of the product markedly prolonged QTc or atrioventricular block II to III patients receiving class I or III antiarrhythmic agents. 

Fig. 6. Influences of different types of antiarrhythmic agents (Vaughan-William s classification) on the shape of cardiac action potentials. First row Class I-agents action potentials of ventricular myocardial cells. Second row (from left to right) Action potential of SA-node cells influence of a )0-hlocker (class II). Action potential of ventricular myocardial cells influence of a class Ill-antiarrhythmic. Action potential of AV nodal cells influence of a class IV-antiarrhythmic (verapamil, diltiazem).

Blocadren EINECS 248-032-6 HSDB 6533 Istalol Timolol Timololum Timopio. See also [25839-75-8]. AnSanginal agent with antiarrhythmic (class II). antihypertensive and antiglaucoma properties. A p-adrenergic blocker. [( ) form] mp = 71.5-72.5°. Merck S Co. Inc. 

Sotalol (Betapace, Sotacor), a nonselective 3-adrenergic blocker, is a methanesulfonanilide antlarrhythmic agent. As an antiarrhythmic, it is dually classified as Class II and Class III because of the similarity of its cardiac effects to both classes. Sotalol is used orally to suppress and prevent the recurrence of life-threatening ventricular arrhythmia. 

PVC s alone with Class IC drugs was not sufficient to reduce mortality in the specific post-infarction population chosen for the CAST study. The failure of Class IC agents in the CAST study and their low efficacy in preventing induction of SVT during electrophysiological testing has increased the interest in alternative approaches to antiarrhythmic therapy, particularly towards Class III agents, a number of which are in Phase II clinical evaluation. 

---