By Rania Gollakner, BS, DVM, MPH

What is propranolol?

Propranolol (brand name: Inderal®, Detensol®, Hemangeol®, Innopran®) is a beta-blocker used to treat abnormal heart rhythms (arrhythmias). It has also been used short-term to treat hypertension caused by thyrotoxicosis or pheochromocytoma.  

Its use in cats, dogs, ferrets, and horses to treat arrhythmias is ‘off label’ or ‘extra label’. Many drugs are commonly prescribed for off label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully as their direction may be significantly different from those on the label.

How is propranolol given?

Propranolol is given by mouth in the form of a tablet, capsule, or liquid solution. It can be given with food or on an empty stomach. If your pet vomits when dosed on an empty stomach, give future doses with food or a treat. Measure the liquid form carefully. Do not stop this drug abruptly; if needed, slowly and gradually discontinue therapy. In the hospital, it may also be administered in the form of an injection into the vein.

This medication should take effect within 1 to 2 hours; however, effects may not be noted outwardly and therefore laboratory tests may need to be done to evaluate this medication’s effectiveness.

What if I miss giving my pet the medication?

Give the missed dose as soon as you remember, and then wait the recommended amount of time between doses. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Side effects are most common in geriatric pets or those with sudden worsening heart disease. Generally, side effects may include lack of energy or diarrhea. More serious side effects include slow heart rate, heart rhythm abnormalities, congestive heart failure, low blood pressure, low blood sugar, and narrowed airways, which may cause coughing, wheezing, trouble breathing, severe lethargy, depression, or collapse.

This short-acting medication should stop working within 24 hours, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

Propranolol should not be used in pets that are allergic to it or pets with certain diagnosed health problems (heart block, overt heart failure, asthma, or a slow heart rate). It should be used cautiously in pets with kidney or liver disease, diabetes, hyperthyroidism, or with abnormal heart sinus node function. Use cautiously in pets taking digoxin. Abruptly stopping this medication may increase the risk of side effects. Its use in pregnant and lactating pets; consider only using it as a last resort in these cases.

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with propranolol: Alpha-2 agonists, amiodarone, antacids, general anesthetics, anticholinergics, bupivacaine, bupropion, calcium channel blockers, cimetidine, digoxin, epinephrine, fluoxetine, furosemide, hydrochlorothiazide, insulin/antidiabetics, lidocaine, methimazole, NSAIDs, phenobarbital, phenothiazines, propylthiouracil, quinidine, reserpine, succinylcholine, tubocurarine, sympathomimetics, theophylline, thyroid hormones, and tricyclic antidepressants.

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.

Is there any monitoring that needs to be done with this medication?

ECGs and blood pressure may need to be monitored while using this medication. Your veterinarian may monitor your pet to be sure that the medication is working.

At home, monitor your pet for serious side effects that may indicate a toxicity.

How do I store propranolol?

Store this medication at room temperature between 15°C and 30°C (59°F and 86°F) and protected from light.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility.

Related Articles