Metoprolol
Also known as: Lopressor, Toprol XL
### Important Information for Pet Owners * **Consistency is Key**: To be effective, your pet must receive all doses exactly as prescribed by your veterinarian. * **Do Not Stop Abruptly**: Never suddenly stop giving this medication without consulting your veterinarian, as it can cause a dangerous spike in heart rate or worsen heart conditions. * **What to Watch For**: Contact your veterinarian immediately if your pet becomes unusually lethargic, tires easily during exercise, develops shortness of breath or a cough, or shows a sudden change in behavior or attitude. * **Diabetic Pets**: If your pet is diabetic, monitor their blood sugar closely, as this medication can hide the normal signs of low blood sugar (hypoglycemia).
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- 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
How it is given
Possible side effects
- Bradycardia
- Lethargy and depression
- Impaired AV conduction
- Congestive heart failure (CHF) or worsening of heart failure
- Hypotension
- Hypoglycemia
- Bronchoconstriction (at high doses)
- Syncope
- Diarrhea
Cautions & contraindications
- 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.
Drug interactions
- 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.
Frequently asked questions
What is Metoprolol used for in pets?
### Important Information for Pet Owners * **Consistency is Key**: To be effective, your pet must receive all doses exactly as prescribed by your veterinarian. * **Do Not Stop Abruptly**: Never suddenly stop giving this medication without consulting your veterinarian, as it can cause a dangerous spike in heart rate or worsen heart conditions. * **What to Watch For**: Contact your veterinarian immediately if your pet becomes unusually lethargic, tires easily during exercise, develops shortness of breath or a cough, or shows a sudden change in behavior or attitude. * **Diabetic Pets**: If your pet is diabetic, monitor their blood sugar closely, as this medication can hide the normal signs of low blood sugar (hypoglycemia).
Is Metoprolol safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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