Class: β-Adrenergic Blocker, Cardioselective
Dosage Forms. Tablet: 25 mg, 50 mg, 100 mg; Extended-Release Tablet: 25 mg, 50 mg, 100 mg, 200 mg
Common FDA Label Indication, Dosing, and Titration.
1. Angina: Adults, 100 mg po daily, may titrate to 100-400 mg po daily
2. Heart failure: Adults, NYHA Class II, 25 mg po daily for 2 wk, may titrate to max 200 mg/d; NYHA Class III-IV, 12.5 mg po daily for 2 wk, may titrate to max 200 mg/d
3. Hypertension: Adults, 25-100 mg po daily, may titrate to 100-400 mg once daily; Children >6 y, 1 mg/kg po daily, may titrate to max 50 mg/d
1. Acute myocardial infarction: Adults, 25-200 mg po daily
2. Atrial fibrillation-cardioversion: Adults, 50-200 mg po daily
3. Cardiac dysrhythmia: Adults, 50-200 mg po daily
MOA. Metoprolol is a cardioselective β-adrenergic blocker used in arrhythmias, hypertension, angina pectoris, and heart failure. It is also effective in decreasing post-MI mortality.
Drug Characteristics: Metoprolol
Medication Safety Issues: Metoprolol
Drug Interactions: Metoprolol
Adverse Reactions: Metoprolol
Efficacy Monitoring Parameters. Decreased BP, reduction of chest pain, decreased number of weekly angina attacks, reduction in use of prophylactic nitroglycerin to relieve chest pain, improvement in signs/symptoms of heart failure.
Toxicity Monitoring Parameters. Signs/symptoms of heart failure, decreased heart rate. Monitor serum electrolytes, and renal function at baseline and periodically.
Key Patient Counseling Points. Take on an empty stomach and avoid alcohol. Avoid abrupt discontinuation, exacerbations of angina may occur. Instruct patients to report signs/symptoms of hypotension, heart failure, or exacerbation of angina with initial dosing and dose changes. This medicine may cause dizziness. Avoid driving, using machinery, or doing anything else that could be dangerous if not alert. Advise diabetic patients to carefully follow blood sugar levels as beta-blockers may mask symptoms of hypoglycemia.
Clinical Pearls. Avoid concomitant use of calcium channel blockers, as concomitant use may significantly affect heart rate or rhythm.