THE PET PHARMACY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

(for veterinary information only)

Brand Name: Propulsid

Available only through compounding pharmacies

Background

One of the stomach's most important functions is to grind the food we eat into fine slurry that will pass through the intestines freely. To accomplish this, the stomach's muscle layers contract in a coordinated rhythm that is initiated by a pacemaker area, similar to the way the heart's rhythm is initiated by its pacemaker area. The rhythm of contraction is called the stomach's motility. If the stomach's motility becomes abnormal, the stomach cannot grind or move food properly.

Motility disorders are common and may be chronic (of long duration) or of sudden onset. When motility is reduced in the stomach, food pools there and creates a sensation of nausea and bloating. In some cases, bile refluxes from the intestine into the stomach causing irritation and more nausea. A medication called metoclopramide acts on the stomach’s pacemaker to normalize stomach contractions.

Metoclopramide also possesses the additional benefit of working on the patient’s brain to relieve symptoms of nausea. Cisapride represents the next generation of this type of medication. Cisapride not only normalizes stomach contractions so that food (and bile) can pass in the correct direction but it also increases motility of the entire GI tract all the way down to the large intestine. This opens up the door for treatment of recurring constipation, something metoclopramide could not help with.

Metoclopramide also had the disadvantage of causing neurologic side effects in the occasional patient by virtue of its ability to act on the brain. Cisapride is not able to cross the blood-brain barrier and thus cannot cause such side effects.

Cisapride was withdrawn from the human market because when it was combined with any of several commonly prescribed drugs, heart rhythm disturbances ensued. (Often people see different specialists for different problems and it was not unusual for one doctor to be unaware of the medications that another doctor has prescribed.) Risks outweighed the benefits and now cisapride must be obtained from a compounding pharmacy for veterinary use. The medications that caused problematic interactions are not as common in veterinary practice; also, most veterinary patients see only one veterinary practice so the interaction issue is much easier to control for pets.

How this Medication is Used

Cisapride is given up to three times daily. It is used to treat nausea due to motility problems in the stomach, though it does not treat the nausea sensation directly in the brain as does its cousin, metoclopramide. It is particularly helpful in patients who have adverse neurologic reactions to metoclopramide but still require stomach motility treatment.

Cisapride has been found helpful in some cases of megaesophagus and is a common treatment for feline megacolon.

Side Effects

If too great a motility effect is created, diarrhea and cramping may result.

Interactions with other Drugs

• The antacids cimetidine and ranitidine will have enhanced activity in patients on cisapride.
  
• Cisapride enhances the sedating properties of the benzodiazepine drugs (such as diazepam).
  
• Cisapride enhances the sedating properties of alcohol (generally not a concern in veterinary patients).
  
• Cisapride works less well with the concurrent use of medications with anticholinergic side effects (antihistamines, some heart medications, some psychoactive drugs).

The drug interaction that led to the removal of cisapride from the human market was the induction of ventricular (heart) arrhythmias when cisapride was used with the antifungal agents ketoconazole or itraconazole.

Concerns and Cautions

• Cisapride tablets should be stored at room temperature in a container that protects the medication from light exposure. Compounded formulations should be stored as recommended by the compounding pharmacist.
  
• If there is question about an intestinal obstruction or perforation, it is best not to use a motility modifier such as cisapride.
  
• Cisapride is not felt to be safe during pregnancy and may also reduce fertility in females taking it.

It is our policy not to give dosing information over the Internet.

Date Published: 5/16/2005 11:39:00 AM
Date Reviewed/Revised: 08/21/2008