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動物種別の用量

用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。

投与経路

禁忌

• Overt or unstable heart failure
• Hypersensitivity to beta-blockers
• Greater than first-degree heart block
• Sinus bradycardia

有害事象

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

薬物相互作用

• 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.

モニタリング

• Cardiac function
• Pulse rate
• ECG (if necessary)
• Blood pressure (if indicated)
• Signs of toxicity (bradycardia, hypotension, lethargy)

過量投与

Overdosage primarily results in extensions of the drug's pharmacologic effects: **hypotension, bradycardia, bronchospasm, cardiac failure, and potentially hypoglycemia**. **Treatment:** * **Decontamination**: If recent oral ingestion, consider emptying the gut and administering activated charcoal. *Caution*: Inducing emesis can be risky as coma and seizures may develop rapidly. * **Monitoring**: Continuous ECG, blood pressure, blood glucose, and potassium. * **Cardiovascular Support**: Treat symptomatically. Use IV fluids and pressor agents for hypotension. * **Bradycardia**: Treat with atropine. If atropine fails, isoproterenol may be given cautiously. A transvenous pacemaker may be necessary. * **Cardiac Failure**: May be treated with digitalis glycosides, diuretics, and oxygen. * **Antidote**: Glucagon (5-10 mg IV - human dose) may increase heart rate and blood pressure and reduce the cardiodepressant effects of metoprolol.