Metoprolol Succinate

What it is and how it works

Mechanism of Action Metoprolol is a beta 1 -selective (cardioselective) adrenergic receptor blocking agent. This preferential effect is not absolute, however, and at higher plasma concentrations, metoprolol also inhibits beta 2 -adrenoreceptors, chiefly located in the bronchial and vascular musculature. Metoprolol has no intrinsic sympathomimetic activity, and membrane-stabilizing activity is detectable only at plasma concentrations much greater than required for beta-blockade. Animal and human experiments indicate that metoprolol slows the sinus rate and decreases AV nodal conduction.

Indications

Metoprolol tartrate tablet is a beta-adrenergic blocker indicated for the treatment of: • Hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. • Angina Pectoris. • Myocardial Infarction, to reduce the risk of cardiovascular mortality when used in conjunction with intravenous metoprolol therapy in patients with definite or suspected acute myocardial infarction in hemodynamically stable patients. Hypertension Metoprolol tartrate tablets are indicated for the treatment of hypertension in adult patients, to lower blood pressure. Lowering blood pressure lowers the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including metoprolol.

Dosage and administration (summary)

• Administer once daily with food or after a meal. Titrate at weekly or longer intervals as needed and tolerated. • Hypertension: Recommended starting dosage is 100 mg daily, in single or divided doses. • Angina Pectoris: Recommended starting dosage is 100 mg daily, given as two divided doses. • Myocardial Infarction: The starting dosage depends upon tolerance of intravenous metoprolol, see full prescribing information. Hypertension Individualize the dosage of metoprolol tartrate tablets. Metoprolol tartrate tablets should be taken with or immediately following meals. The usual initial dosage is 100 mg daily in single or divided doses.

Contraindications

Metoprolol tartrate tablets are contraindicated in severe bradycardia, second-or third-degree heart block, cardiogenic shock, systolic blood pressure <100, decompensated heart failure, sick sinus syndrome (unless a permanent pacemaker is in place), and in patients who are hypersensitive to any component of this product. • Known hypersensitivity to product components. • Severe bradycardia: Greater than first degree heart block, or sick sinus syndrome without a pacemaker.

Warnings and precautions

• Abrupt cessation may exacerbate myocardial ischemia. • Heart Failure: Worsening cardiac failure may occur. • Bronchospastic Disease: Avoid beta-blockers. • Pheochromocytoma: Initiate therapy with an alpha blocker. • Major Surgery: Avoid initiation of high-dose extended-release metoprolol in patients undergoing non-cardiac surgery. Do not routinely withdraw chronic beta-blocker therapy prior to surgery. ( 5.5 , 6.1 ) • Diabetes: May mask symptoms of hypoglycemia. • Thyrotoxicosis: Abrupt withdrawal in patients with thyrotoxicosis might precipitate a thyroid storm.

Pregnancy

Pregnancy Risk Summary Available data from published observational studies have not demonstrated an association of adverse developmental outcomes with maternal use of metoprolol during pregnancy ( see Data).

Source: Metoprolol (Metoprolol Tartrate) — US FDA prescribing information, 2026-07-27, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.