isoproterenoli

Isoproterenol, also known as isoprenaline, is a synthetic catecholamine that acts as a non-selective beta-adrenergic agonist. It stimulates both beta-1 and beta-2 receptors, producing effects on the heart and on smooth muscle in the airways and vasculature.

Pharmacodynamics involve beta-1 stimulation increasing heart rate, myocardial contractility, and AV conduction, while beta-2 stimulation causes bronchodilation and vasodilation in skeletal muscle. The net effect is an increase in cardiac output with a potential decrease in peripheral resistance, often accompanied by tachycardia and palpitations.

Isoproterenol is generally given by intravenous infusion for rapid onset; it can be administered subcutaneously or intramuscularly in certain settings. It has a short duration of action and is rapidly inactivated by catecholamine-metabolizing enzymes such as monoamine oxidase and catechol-O-methyltransferase.

Clinical uses have historically included temporary treatment of bradycardia and high-grade AV block, support of cardiac output in specific shock states, and pharmacologic stimulation during diagnostic electrophysiology studies to provoke tachyarrhythmias or assess conduction. Because of the risk of inducing tachyarrhythmias and the availability of safer alternatives, its use has declined and is now largely restricted to specialized or research contexts.

Common adverse effects include tachycardia, palpitations, tremor, headache, and anxiety, with possible myocardial ischemia in patients with coronary artery disease. It can cause electrolyte shifts such as hypokalemia and glucose changes via beta-2 effects. Contraindications include tachyarrhythmias, severe hypotension, obstructive heart disease, and certain catecholamine-sensitive conditions such as pheochromocytoma. Brand names include Isuprel.