Beta-adrenergic blocking agents
Beta-adrenergic blocking agents
overview Nonselective beta-blockers act at both beta1 and beta2 receptors,whereas cardioselective beta-antagonists primarily block beta-1 receptors. Do not induce postural hypotension Effective in treating angina,cardiac arrhythmias,myocardial infarction,and glaucoma
overview ◼ Nonselective beta-blockers act at both beta1 and beta2 receptors, whereas cardioselective beta-antagonists primarily block beta-1 receptors. ◼ Do not induce postural hypotension ◼ Effective in treating angina, cardiac arrhythmias, myocardial infarction, and glaucoma
propranolol Nonselective beta-antagonist Blocks both beta-1 and beta-2 receptors
propranolol ◼ Nonselective beta-antagonist ◼ Blocks both beta-1 and beta-2 receptors
Actions Cardiovascular:propranolol diminishes cardiac output,having both negative inotropic and chronotropic effects. Cardiac output,work,and oxygen consumption are decreased. Attenuating supraventricular cardiac arrhythmias
Actions ◼ Cardiovascular: propranolol diminishes cardiac output, having both negative inotropic and chronotropic effects. ◼ Cardiac output, work, and oxygen consumption are decreased. ◼ Attenuating supraventricular cardiac arrhythmias
actions Peripheral vasoconstriction:reduction of cardiac output leads to decreased blood pressure. Bronchoconstriction beta-blockers are thus contraindicted in patients with asthma Increased Na+retention Disturbances in glucose metabolism
actions ◼ Peripheral vasoconstriction: reduction of cardiac output leads to decreased blood pressure. ◼ Bronchoconstriction beta-blockers are thus contraindicted in patients with asthma ◼ Increased Na+ retention ◼ Disturbances in glucose metabolism
Actions Blocks action of isoproterenol:have the ability to block the actions of isoproterenol on the cardiovascular system
Actions ◼ Blocks action of isoproterenol: have the ability to block the actions of isoproterenol on the cardiovascular system
52 Broncho constriction B2 Vasoconstncton Na+ Propranolol 88nt品n Rate Force Propranolol Cardiac output Acebutolol Atenolol Metoprolol
Therapeutic effects Hypertension: Glaucoma: Migraine:propranolol is also effective in reducing migraine episodes. Hyperthyroidism:in blunting the widespread sympathetic stimulation that occurs in hyperthyroidism Myocardial infarction:following a myocardial infarction reduces infarct size and hastens recovery
Therapeutic effects ◼ Hypertension: ◼ Glaucoma: ◼ Migraine: propranolol is also effective in reducing migraine episodes. ◼ Hyperthyroidism: in blunting the widespread sympathetic stimulation that occurs in hyperthyroidism ◼ Myocardial infarction: following a myocardial infarction reduces infarct size and hastens recovery
Adverse effects Bronchoconstriction: ■Arrhythmia Sexual impairment: Disturbances in metabolism:beta blockade leads to decreased glycogenolysis and decreased glucagon secretion.Hypoglycemia. Drug interactions:interfere with the metabolism cimetidine
Adverse effects ◼ Bronchoconstriction: ◼ Arrhythmia ◼ Sexual impairment: ◼ Disturbances in metabolism: beta blockade leads to decreased glycogenolysis and decreased glucagon secretion. Hypoglycemia. ◼ Drug interactions: interfere with the metabolism cimetidine
Acebutolol,atenolol,metoprolol and esmolol Selective beta1 antagonists To eliminate the unwanted bronchoconstrictor effect of Pronounced at low doses and is lost at high drug doses
Acebutolol, atenolol, metoprolol and esmolol ◼ Selective beta1 antagonists ◼ To eliminate the unwanted bronchoconstrictor effect of ◼ Pronounced at low doses and is lost at high drug doses