What is propranolol?
Propranolol (brand names Inderal®, Detensol®, Hemangeol®, Innopran®) is a beta-blocker used off label (extra label) to treat abnormal heart rhythms (arrhythmias) in cats, dogs, ferrets, and horses. It has also been used short-term to treat hypertension caused by thyrotoxicosis or pheochromocytoma.
Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they 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. Measure the liquid form carefully.
- It may also be administered in hospital as an injection into the vein.
- 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.
- Do not stop this drug abruptly; if needed, slowly and gradually discontinue therapy.
This medication should take effect within 1 to 2 hours; however, effects may not be noted outwardly, and laboratory tests may need to be done to evaluate this medication’s effectiveness.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then wait the recommended amount of time between doses. Do not give the pet two doses at once.
Are there any potential side effects?
Propranolol may cause the following side effects:
- lack of energy
- diarrhea
Side effects are most common in geriatric pets or those with sudden worsening heart disease. Serious adverse reactions may occur. If any of the following signs develop, stop giving propranolol and contact your veterinarian immediately:
- slow heart rate
- heart rhythm abnormalities
- congestive heart failure
- low blood pressure
- low blood sugar
- 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:
- who are allergic to it or
- who have certain diagnosed health problems (heart block, overt heart failure, asthma, or a slow heart rate)
Propranolol should be USED WITH CAUTION in pets:
- with kidney or liver disease
- with diabetes
- with hyperthyroidism
- with abnormal heart sinus node function.
- who are taking digoxin
Abruptly stopping this medication may increase the risk of side effects. Its use in pregnant and lactating pets has not been tested; consider 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
- anticholinergics
- bupropion
- calcium channel blockers
- cimetidine
- digoxin
- epinephrine
- fluoxetine
- furosemide
- hydrochlorothiazide
- insulin/antidiabetics
- methimazole
- nonsteroidal anti-inflammatory drugs (NSAIDs)
- phenobarbital
- phenothiazines
- quinidine
- sympathomimetics
- theophylline
- thyroid hormones
- tricyclic antidepressants
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking.
Is any monitoring needed with this medication?
- Your veterinarian may monitor your pet’s ECGs and blood pressure while your pet is using propranolol.
- 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 toxicity.
How do I store propranolol?
- Store this medication at room temperature between 15°C and 30°C (59°F and 86°F).
- Protect 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.
