美托洛爾

用途

• As an oral beta blocker
• For rate control in chronic atrial fibrillation
• For CHF (early/mild or well-controlled)
• To decrease the incidence of atrial fibrillation and flutter in dogs undergoing valve surgery

給藥方式

可能的副作用

• Bradycardia
• Lethargy and depression
• Impaired AV conduction
• Congestive heart failure (CHF) or worsening of heart failure
• Hypotension
• Hypoglycemia
• Bronchoconstriction (at high doses)
• Syncope
• Diarrhea

注意事項與禁忌

• Overt or unstable heart failure
• Hypersensitivity to beta-blockers
• Greater than first-degree heart block
• Sinus bradycardia
• > **Withdrawal Warning**: Do not abruptly discontinue metoprolol therapy in chronic users. Abrupt cessation can lead to rebound tachycardia and exacerbation of clinical signs; taper the dose gradually. * **Respiratory Disease**: Use with caution in patients with bronchospastic lung disease, even though it is relatively beta1-selective. * **Hepatic Impairment**: Use cautiously in patients with significant hepatic insufficiency due to extensive hepatic metabolism. * **Endocrine**: Can mask clinical signs of hypoglycemia and thyrotoxicosis. Use cautiously in labile diabetic patients as it can cause hypoglycemia or hyperglycemia. * **Cardiac**: Use cautiously in patients with sinus node dysfunction or compensated CHF.

藥物相互作用

• General Anesthetics: Increased risk for heart failure and hypotension due to additive myocardial depressant effects.
• Calcium-Channel Blockers (e.g., diltiazem, verapamil, amlodipine): Concurrent use should be done with caution; additive negative inotropic and chronotropic effects, particularly in patients with preexisting cardiomyopathy or CHF.
• Digoxin: May increase negative effects on SA or AV node conduction.
• Diuretics (thiazides, furosemide): May increase the hypotensive effect of metoprolol.
• Hydralazine: May increase the risks for pulmonary hypertension in uremic patients.
• Quinidine: May increase metoprolol plasma concentrations.
• Reserpine: Potential for additive effects including hypotension and bradycardia.
• SSRI Antidepressants (e.g., fluoxetine, sertraline, paroxetine): May increase metoprolol plasma concentrations.
• Sympathomimetics (e.g., metaproterenol, terbutaline, epinephrine, phenylpropanolamine): May have their actions blocked by metoprolol, and they may in turn reduce the efficacy of the beta-blocker.

常見問題