Metoprolol is a beta blocker and antihypertensive medication marketed as Lopressor.
Information about Metoprolol
Metoprolol is a cardioselective beta-blocker that is widely used in the treatment of hypertension and angina pectoris.
Liver safety of Metoprolol
Metoprolol has been linked to rare cases of drug induced liver injury.
Mechanism of action of Metoprolol
Metoprolol (met" oh proe' lol) is considered a “selective” beta-adrenergic receptor blocker in that it has potent activity against beta-1 adrenergic receptors which are found in cardiac muscle, but has little or no activity against beta-2 adrenergic receptors found on bronchial and vascular smooth muscle.
FDA approval information for Metoprolol
Metoprolol was approved for use in the United States in 1978 and is still widely used in the therapy of hypertension and angina pectoris, with more than 27 million prescriptions filled yearly. Metoprolol is also used to reduce the risk of cardiovascular mortality after acute myocardial infarction.
Dosage and administration for Metoprolol
Metoprolol is available in standard 50 and 100 mg tablets as well as 25, 50, 100 and 200 mg extended release tablets in generic forms as well as under the trade name of Lopressor and Toprol XL, and as a fixed combination with a hydrochlorothiazide as Lopressor HCT and Dutoprolol. Parenteral formulations for intravenous use are also available. The usual initial oral dose of metoprolol in adults is 100 mg daily in one or two divided doses daily, with subsequent adjustment based upon clinical response and tolerance, the usual maintenance dosage being 100 to 400 mg daily. The entended release forms are given in doses of 25 to 100 mg once daily.
Side effects of Metoprolol
Common side effects include bradycardia, hypotension, fatigue, dizziness, depression, insomnia, memory loss and impotence. Beta-blockers are contraindicated in patients with asthma, bradycardia and heart failure and should be used cautiously in the elderly and in patients with diabetes. As with all beta-blockers, sudden withdrawal can trigger rebound hypertension.