Propantheline Bromide

What is propantheline bromide?

Propantheline bromide (brand name: Pro-Banthine®) is an antimuscarinic used to treat muscle spasms, incontinence, diarrhea, and sometimes slow heart rate. In horses, it is used to relax the muscles for procedures in the colon. 

Its use in cats, dogs, and horses to treat diarrhea and other disorders 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 directions may be significantly different from those on the label.

How is propantheline bromide given?

Propantheline bromide is given by mouth in the form of a tablet or a compounded liquid. In some countries, it may also be available as an injection. Measure liquid forms carefully. Give the oral form on an empty stomach; however, if vomiting occurs when dosed on an empty stomach, try giving future doses with a small treat or a small amount of food. Allow free access to water at all times if possible while giving this medication.

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 when you remember, but if it is close to the time for the next dose, skip the dose you missed and give it at the next scheduled time, and return to the regular dosing schedule. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Side effects include dry mouth, dry eyes, fast heart rate, difficulty urinating, and constipation. In cats, vomiting and drooling have been reported. Serious side effects include prolonged constipation (more than 2 days) or an inability to urinate.

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?

Propantheline bromide should not be used in pets that are allergic to it or similar drugs. Do not use in pets with certain heart, bladder, or intestinal problems, glaucoma, or myasthenia gravis (a nerve disorder). It should be used cautiously in pets with liver, kidney, or heart disease, high thyroid levels, high blood pressure, enlarged prostate, or an infection in the intestines. Propantheline bromide should be used cautiously in very old or very young pets, or in pregnant or nursing pets.

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with propantheline bromide: antihistamines, antiarrhythmics, benzodiazepines, cimetidine, digoxin, meperidine, nitrates, nitrofurantoin, phenothiazines, sympathomimetics, ranitidine, or thiazide diuretics.

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?

There is no specific monitoring that needs to be done while your pet is taking this medication. If indicated, heart rate and heart rhythm may need to be monitored. Your veterinarian may monitor your pet to be sure that the medication is working. Monitor your pet at home for serious side effects.

How do I store propantheline bromide?

Store this medication at room temperature and 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.