Ephedrine

Ephedrine treats low blood pressure during anesthesia, as well as urinary incontinence in dogs. A central nervous system stimulant, it can also treat nasal congestion and is prescribed by veterinarians as an “off-label” drug.

Keep reading for more information about the recommended dosage, efficacy, and side effects of ephedrine for dogs.

Dosage

Ephedrine comes in capsule form or as an injection. The solution for injection is available in concentrations ranging from 25 to 50 ml/kg, while capsules come in two dosage sizes: 25 mg and 50 mg.

The recommended dosage of ephedrine for dogs varies depending on the condition being treated and how it is being administered. For example, the dosage is 2 mg per pound (4 mg/kg) or 12.5 to 50 mg by mouth every 8 to 12 hours when treating urinary incontinence, but the dosage amount drops when ephedrine is used as a bronchodilator.

The clinical signs of ephedrine overdose can appear at dosages of 5 to 6 mg/kg, while death may occur at 10 to 12 mg/kg.

Efficacy

Ephedrine for dogs is a central nervous system stimulant that stimulates the release of the chemical neorepinephrine. This not only increases heart rate and blood pressure, but also dilates the bronchial tree and contracts the muscle at the neck of the bladder.

Ephedrine can be used to treat low blood pressure (hypotension) during anesthesia. It can be used when hypotension persists or as an alternative when dopamine or dobutamine are found to be ineffective. However, dosing can be difficult due to the high concentration of ephedrine preparation, while it can also cause a greater increase in heart rate compared with dopamine and dobutamine.

Ephedrine has been shown to improve cardiac output and oxygen delivery in anesthetized hypotensive dogs. The preliminary investigation also showed that when used to treat dogs undergoing routine surgeries to treat hypotension, ephedrine treatment (0.2 mg/kg IV) caused an increase in mean arterial blood pressure for less than 5 minutes.

Ephedrine can also be used to treat urinary incontinence in dogs. It has been shown to increase urethral pressure and urethral functional length of continent female dogs, improving urethral and bladder function. However, ephedrine has been shown to be less efficacious than phenylpropanolamine at increasing urethral tone and maximal urethral closure pressure.

Side effects

When prescribed by a veterinarian, ephedrine is generally safe to use. However, side effects to be aware of with ephedrine for dogs include:

• Restlessness

• Irritability

• Loss of appetite

• Increased heart rate (tachycardia)

• Panting

• High blood pressure

While the effects of ephedrine for dogs will typically last less than 24 hours, they may last longer in pets suffering from liver or kidney disease. In severe cases, collapse may also occur.

Considerations

Ephedrine for dogs should only ever be administered when prescribed by a veterinarian. It’s also essential that you follow dosage instructions carefully.

Drug interactions

Ephedrine may interact with the following drugs:

• Blood pressure medications (alpha-blockers, beta-blockers)

• Tranquilizers (acepromazine)

• Immunosuppressants (cyclosporine)

• Heart medications (digoxin)

• Canine behavior medications (monoamine oxidase inhibitors )

• Antacids (sodium bicarbonate)

• Reserpine

• Respiratory medications (theophylline)

• Tricyclic antidepressants

• Urinary alkalinizers

If used in conjunction with digoxin or tricyclic antidepressants, ephedrine can cause heart arrhythmias. When combined with urinary alkalinizers, ephedrine may produce toxic effects.

It’s essential to tell your veterinarian about all medications your dog is taking before ephedrine is prescribed or administered.

Allergic reactions and sensitivity

Ephedrine should not be used in dogs with a known allergy or sensitivity to the drug. It should also not be given to dogs with:

• Severe heart disease

• Heart rhythm abnormalities

It should also be used with caution in dogs suffering a range of other conditions, including:

• Hypothyroidism

• Diabetes

• High blood pressure (hypertension)

• Heart disease

• Glaucoma

• Enlarged prostate

Finally, be cautious when using ephedrine on pregnant or nursing dogs as its safety has not been comprehensively studied.

Frequently asked questions

How is ephedrine stored?

Ephedrine should be stored at room temperature in a sealed container. It should also be protected from heat and sunlight.

What class of drug is ephedrine?

Ephedrine is classed as a sympathomimetic alkaloid.

What should I do if I miss a dose of ephedrine for my pet?

If you remember well before the next dose is due, you can give the dose as soon as possible. However, if it’s not long until the next dose is due to be administered, skip the missed dose — you should never give double doses of ephedrine to your pet. You can then continue with the normal dosing schedule.

What should I do if my pet has an adverse reaction to ephedrine or an overdose?

Seek immediate veterinary attention for your dog.