Cisapride is a gastrointestinal prokinetic medication that veterinarians may discuss for cats with chronic constipation, megacolon or delayed gastric emptying, since it acts on the nerve pathways that coordinate motility along the GI tract. It is not sold under any commercial brand in the United States today, which means every cisapride prescription for cats is filled through a compounding pharmacy. Because cats with motility disorders often need consistent, long-term therapy, compounded flavored formulations are commonly considered to support at-home dosing.
What Is Cisapride and Why Is It Only Available Through Compounding Pharmacies?
Cisapride belongs to a class of medications known as prokinetics, compounds that act on the nerves controlling movement of the gastrointestinal tract, rather than working like a laxative. It was originally sold in the United States under the brand name Propulsid for human gastrointestinal conditions, but the manufacturer discontinued it in 2000, and no company has brought a replacement to market since (for humans or animals).
Because there’s no commercial version to prescribe today, cisapride prescribed for cats is prepared under the FDA's guidance on compounding animal drugs from bulk drug substances, the pathway compounding pharmacies use to prepare medications that have no commercially manufactured equivalent. A compounding pharmacy with appropriate sourcing and quality standards is the only way a veterinarian can obtain it for a patient.
What GI Conditions Might Lead a Veterinarian to Discuss Cisapride for Cats?
Feline chronic constipation is one of the most frequent contexts in which cisapride comes up. Cats who strain repeatedly, produce hard or infrequent stool, or show a pattern of recurring constipation despite dietary and environmental changes may have cisapride discussed as part of a broader management plan.
Megacolon, a condition in which the colon becomes abnormally dilated and loses effective contractile function, is another presentation where veterinarians may consider cisapride, particularly in cases of feline idiopathic megacolon identified before more advanced intervention is needed. Delayed gastric emptying, where the stomach empties more slowly than expected, is a third context in which a veterinarian may discuss a prokinetic like cisapride as one approach among several used for gastrointestinal motility disorders in small animal patients.
Your veterinarian will evaluate your cat's full history, diet, hydration status and physical examination findings before determining whether cisapride or another approach fits your cat's situation.
How Does Cisapride Work as a Prokinetic?
Cisapride acts as a serotonin (5-HT4) receptor agonist, which enhances the release of acetylcholine from nerves in the myenteric plexus, the network of neurons that coordinates smooth muscle contractions along the gastrointestinal tract. This mechanism is why cisapride is described as a prokinetic rather than a laxative: it acts on the nerves and muscle of the GI tract itself rather than working by drawing water into the stool. Veterinarians who discuss cisapride are typically doing so in the context of motility rather than stool consistency alone.
Why Do Compounded Flavored Formulations Matter for Cats on Long-Term Cisapride Therapy?
Motility conditions like megacolon and chronic constipation are often managed over months or years rather than days, which makes finding a formulation a cat will reliably take especially important. A cat who resists a capsule or spits out a tablet cannot receive a consistent dose, and inconsistent dosing undermines a medication that depends on steady, long-term administration to remain part of a management plan.
Cisapride is commonly compounded into several forms, including flavored oral liquid, transdermal pen, mini tablet, chew treat or capsule, so a veterinarian can choose whichever fits an individual cat best, whether that comes down to weight-based dosing precision for a smaller cat, a known sensitivity to a specific ingredient, or simply what the cat will take consistently. Among Mixlab's compounded feline cisapride scripts over the past 12 months, flavored oral liquid was by far the most common, accounting for roughly two in three fills.
Shop compounded cisapride for cats
What Are the Side Effects of Cisapride for Cats?
Veterinarians commonly ask owners to monitor for gastrointestinal effects when a cat starts cisapride, since the medication's mechanism increases motility throughout the GI tract. Loose stool, mild abdominal discomfort or an increased frequency of defecation are effects some owners notice, particularly in the early days of therapy. These effects are generally described as mild, but any change that seems severe or persistent should be reported to your veterinarian.
Because cisapride's withdrawal from the human market was tied to cardiac rhythm concerns when combined with certain other medications, veterinarians consider a cat's complete medication list carefully before prescribing it. This is one reason a full and current medication history matters every time a new prescription is discussed, even for a medication with a long history of veterinary use.
Any change in your cat's behavior, appetite or energy level after starting cisapride should be communicated to your veterinarian, particularly if it develops shortly after a dose or does not resolve on its own.
Frequently Asked Questions About Cisapride for Cats
Is Cisapride Available at Regular Pharmacies?
No. Cisapride is not manufactured or sold as a commercial product in the United States for either human or veterinary use, so a standard retail pharmacy will not stock it. A compounding pharmacy prepares cisapride from raw active pharmaceutical ingredients to fill a valid prescription from your veterinarian.
Why Does My Cat Need a Compounded Medication?
Your cat needs a compounded version of cisapride because no commercially manufactured product currently exists for veterinarians to prescribe. Compounding also allows the medication to be prepared as a flavored oral liquid, transdermal pen, mini tablet, chew treat or capsule, which can make long-term administration more manageable for a cat. A valid prescription from your veterinarian is required either way.
What Is Cisapride Used for in Cats?
Cisapride is a prokinetic medication veterinarians may discuss for cats with chronic constipation, megacolon or delayed gastric emptying. It is typically considered as one part of a broader management plan that may include diet, hydration support and other interventions your veterinarian recommends. Your veterinarian determines whether cisapride fits your cat's specific presentation.
How Long Does It Take Cisapride to Start Working in Cats?
Response time varies by cat and by the condition being addressed, and your veterinarian will typically plan a follow-up to assess whether cisapride appears to be supporting motility as intended. Some owners notice a change within the first several days, while others may need a longer trial before a pattern emerges. Your veterinarian is best positioned to interpret your cat's individual response.
What Is the Cisapride Dosage for Cats?
In general, cisapride dosing for cats is weight-based and determined by your veterinarian based on your cat's size, age, health history and the condition being treated. Timing and frequency will also vary. Your veterinarian will prescribe the specific dose and schedule appropriate for your pet. Do not adjust the dose without consulting them first.
Does Cisapride Interact With Other Medications?
Cisapride can interact with certain other medications, so it is important to give your veterinarian a complete picture of everything your cat is currently taking, including any supplements. Certain antifungal and antibiotic medication classes are well-established examples that may interact with cisapride, and your veterinarian will screen for these before prescribing. Never start or stop a medication without consulting your veterinarian first.
What Should I Do If My Cat Misses a Dose of Cisapride?
If you miss a dose, give it as soon as you remember (unless it is close to the time of the next scheduled dose, in which case skip the missed dose and continue as normal). Never give two doses at once to make up for a missed one. If you are unsure what to do, contact your veterinarian for guidance.
Key Takeaway
Cisapride is a prokinetic medication that veterinarians may discuss for cats with chronic constipation, megacolon or delayed gastric emptying, working through nerve pathways that coordinate GI motility rather than through a laxative effect. Because no commercial cisapride product remains on the market for humans or animals, every prescription is prepared by a compounding pharmacy to support the consistent, long-term dosing these conditions often require. If your veterinarian has discussed cisapride for your cat, a valid prescription is required for any compounded formulation.
Compounded medications are prepared by a licensed pharmacy for an individual patient based on a veterinarian's prescription. Because they're customized rather than mass-manufactured, they don't go through the FDA's premarket review process that FDA-approved drugs do.