Overview of Phenylpropanolamine for Dogs and Cats

 Phenylpropanolamine, also known as Proin®, is commonly used for treatment of urinary incontinence, and nasal congestion in dogs and cats. Phenylpropanolamine is commonly referred to the the letters “PPA”. 

Phenylpropanolamine releases the chemical messenger norepinephrine from nerves. Norepinephrine stimulates alpha-adrenergic and beta-adrenergic receptors in a number of organs.

The release of norepinephrine results in the cardiovascular effects of constriction of blood vessels, increased heart rate and increased blood pressure.

Another effect of phenylpropanolamine is constriction of blood vessels in the nasal cavity, which reduces nasal congestion.

An increase in the tone of sphincter muscles, primarily of the bladder, occurs after repeated administration.

This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.

Brand Names and Other Names of Phenylpropanolamine

This drug is registered for use in humans only.

Phenylpropanolamine is no longer commercially available in the United States; however, some veterinarians still have supplies of this drug and the drug is available through compounding pharmacies.

Human formulations: None

Veterinary formulations: Proin®

Uses of Phenylpropanolamine for Dogs and Cats

The primary use of phenylpropanolamine is treatment of urinary incontinence (involuntary leakage of urine from the bladder). The benefit is gained by increasing sphincter tone of the urethra (the tube carrying urine from the bladder).

Phenylpropanolamine also has been used to treat nasal congestion.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, phenylpropanolamine can cause side effects in some animals.

Phenylpropanolamine should not be used in animals with known hypersensitivity or allergy to the drug.

Phenylpropanolamine should be used with caution in animals with glaucoma, diabetes, overactive thyroid, high blood pressure or heart disease.

Phenylpropanolamine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with phenylpropanolamine. Such drugs include ephedrine, aspirin and tricyclic antidepressants.

Adverse effects of phenylpropanolamine include restlessness, high blood pressure and lack of appetite.

How Phenylpropanolamine Is Supplied

Phenylpropanolamine may be available through compounding pharmacies by prescription from your veterinarian. It is specifically made to order and can be produced in a variety of concentrations.

Dosing Information of Phenylpropanolamine for Dogs and Cats

Medication should never be administered without first consulting your veterinarian.

The typical dose of phenylpropanolamine is 12.5 to 50 mg three times daily, depending on weight.

Cats typically receive 12.5 mg per cat three times daily or one 75 mg sustained-release capsule once daily.

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse.