What is phenylpropanolamine?
Phenylpropanolamine (brand names: Proin®, Propalin®, Cystolamine®, Uricon®, Uriflex-PT®) is a sympathomimetic medication used in dogs and cats to treat urinary incontinence due to poor muscle tone in the urethral sphincter.
It is used off label (extra label) to treat urinary incontinence in cats. 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 phenylpropanolamine given?
- Phenylpropanolamine is given by mouth in the form of a tablet or liquid.
- Measure liquid forms carefully.
- If using extended-release tablets, do not split or crush them.
- Phenylpropanolamine may be given with or without food; however, if vomiting occurs when dosed on an empty stomach, give future doses with food.
- Always provide access to fresh water.
- If incontinence occurs at night, give the largest dose at night, before going to sleep.
This medication will take effect quickly, in about 1 to 2 hours, and improvement in clinical signs should follow.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.
Are there any potential side effects?
Phenylpropanolamine may cause the following side effects:
- Vomiting, diarrhea, lack of appetite
- Increased thirst
- Restlessness
- Irritability
- Difficulty urinating
Serious adverse reactions may occur. If any of the following signs develop, stop giving phenylpropanolamine and contact your veterinarian immediately:
- Seizures
- Collapse
- Stroke-like signs (e.g., not being able to walk)
Drug sensitivities can develop over time, with repeated exposure. Your pet may have no reaction after the first few doses but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment (e.g., irregular breathing, rash, fever, puffiness and swelling around the face) and notify your veterinarian if you have any concerns.
Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. 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?
DO NOT USE phenylpropanolamine in:
- Pets that are allergic to the medication
- Pets that are pregnant
USE WITH CAUTION in:
- Pets with glaucoma
- Pets with seizures
- Pets with enlarged prostates
- Pets with elevated thyroid hormone
- Pets with diabetes mellitus
- Pets with heart or vessel disorders
- Pets with kidney disease
- Pets with high blood pressure
- Pets that are nursing (safety has not been studied)
Are there any drug interactions I should be aware of?
The following medications should be used with caution when given with phenylpropanolamine:
- Aspirin
- Monoamine oxidase inhibitors (MAOIs)
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Other sympathomimetics
- Tricyclic antidepressants
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.
Is any monitoring needed with this medication?
- Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
- Blood pressure should be monitored frequently when your pet first starts taking phenylpropanolamine, and then at least twice per year.
- At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.
How do I store phenylpropanolamine?
- Store this medication at room temperature and protect from light and moisture.
- Keep the container out of reach of children and pets.
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. Be prepared to provide information about the product and your pet's weight and symptoms.
