Cisapride

Cisapride is a gastrointestinal prokinetic drug that enhances coordinated movement through the stomach, small intestine and colon. A principal veterinary use is management of chronic constipation and megacolon in cats. It is also used for selected gastric-emptying and reflux disorders and is commonly supplied to veterinary patients as a compounded preparation.

Group

Gastrointestinal prokinetic

Mechanism of Action

Cisapride stimulates serotonin 5-HT4 receptors on neurons in the myenteric plexus, enhancing acetylcholine release and cholinergic transmission within the intestinal wall. This increases coordinated smooth-muscle activity, promotes gastric emptying and intestinal transit, and can increase lower esophageal sphincter pressure. Its prokinetic action extends to the colon, accounting for its usefulness in feline constipation and megacolon.

Dose Rates

Dogs

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 8–12 h
Higher-dose gastrointestinal dysmotility treatment	0.5–1 mg/kg	PO		Upper-range alternative; the source does not separately assign a repeat interval.
Prevention of anesthetic gastroesophageal reflux	1 mg/kg	IV
Gastroesophageal reflux adjunct	0.1–0.5 mg/kg	PO	Every 8–24 h	Adjunct to appropriate acid suppression; administer at least 30 minutes before food where feasible.
Esophagitis-associated stricture prevention adjunct	0.5–0.75 mg/kg	PO	Every 8 h
Micturition disorder adjunct	0.5 mg/kg	PO	Every 8 h	Historical attempt to stimulate detrusor contraction; exclude obstruction and evaluate the underlying disorder.
Historical megaesophagus treatment	Reference only	PO		The older source proposes 0.55 mg/kg orally once to three times daily before food, but the other monograph advises avoidance in canine megaesophagus because lower-esophageal-sphincter tone can increase without useful esophageal motility. Do not promote this conflicting indication to routine calculation.

Cats

Use / stage	Dose	Route	Schedule	Instructions
Constipation and gastrointestinal dysmotility	2.5–5 mg/animal	PO	Every 8–12 h
Higher-dose gastrointestinal dysmotility treatment	1 mg/kg	PO	Every 8 h
Esophagitis-associated stricture prevention adjunct	0.5–0.75 mg/kg	PO	Every 8 h
Chronic constipation or megacolon	1.25–2.5 mg/animal	PO	Every 8–12 h	Use alongside dietary treatment and a stool-softening plan; halve the usual dose with hepatic insufficiency.
Chronic constipation or megacolon	5 mg/animal	PO	Every 8–12 h
Size-based constipation treatment	Reference only	PO		With stool-softening and dietary management: 2.5 mg per dose for cats up to 10 lb, 5 mg at 11 lb or above, sometimes 7.5 mg above 16 lb, three times daily before food. The source leaves a weight gap and does not define verified tablet bands.
Gastric stasis	0.1 mg/kg	PO	Every 8–12 h

Horses

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1 mg/kg	IV		Requires a specifically compounded injectable preparation.
Foal gastric dysmotility after periparturient asphyxia	10 mg/animal	PO	Every 6–8 h	Foals only; allow adequate healing of damaged bowel and exclude obstruction before a prokinetic.

Mice

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 12 h

Rats

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 12 h

Gerbils

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 12 h

Hamsters

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 12 h

Guinea pigs

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 12 h
Ileus	Reference only	PO		0.5 mg/kg every 8–12 hours appears with an explicitly assumed, rather than established, oral route. Preserve as a reference until the route is confirmed.

Chinchillas

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal dysmotility	0.1–0.5 mg/kg	PO	Every 12 h
Ileus	Reference only	PO		0.5 mg/kg every 8–12 hours appears with an explicitly assumed, rather than established, oral route. Preserve as a reference until the route is confirmed.

Rabbits

Use / stage	Dose	Route	Schedule	Instructions
Gastrointestinal stasis	0.5 mg/kg	PO	Every 6–12 h	Exclude obstruction, restore hydration and provide appropriate nutritional support; some protocols add metoclopramide.
Gastric stasis	0.5 mg/kg	PO	Every 8 h	Via a safe oral/NG plan after obstruction has been excluded; another protocol uses ranitidine as a separate adjunct.

Indications

Management of chronic constipation, obstipation and megacolon in cats with residual colonic responsiveness.
Treatment of delayed gastric emptying and functional gastric stasis in dogs and cats.
Adjunctive management of gastroesophageal reflux and reflux esophagitis through improved gastric emptying and lower esophageal sphincter function.
Treatment of selected functional or postoperative ileus, including specialist use in horses.

Contraindications

Gastrointestinal obstruction.
Avoid in canine megaesophagus because lower esophageal sphincter pressure may increase.
Gastrointestinal perforation or hemorrhage where increased motility could be harmful.

Interactions

Anticholinergics reduce response.
CYP450 or P-glycoprotein inhibitors can increase exposure and toxicity.
Avoid combinations with QT-prolonging drugs such as amiodarone, clarithromycin, procainamide, quinidine, sotalol or tricyclic antidepressants.
Azoles, macrolides, chloramphenicol and cimetidine can inhibit clearance; risk varies by species and actual product.
Changed gastrointestinal transit may alter absorption of narrow-therapeutic-index oral medicines; warfarin effects or benzodiazepine sedation may increase.

Adverse effects

Abdominal discomfort
Vomiting or diarrhea
Neurologic effects with overdose
Potential cardiac rhythm effects

Toxicity

High overdose can cause aggression, ataxia, fever, vomiting and diarrhea. Cardiac toxicity is established in people; monitor susceptible veterinary patients.

Preparations

Preparation	Form	Strength	Route
Compounded cisapride monohydrate suspension 10 mg/mL Monohydrate mass basis from the supplied recipe; no anhydrous equivalence is inferred. Refrigerate; described stability 30 days.	Oral Liquid	10 mg / mL	PO
Compounded cisapride 1 mg/mL oral suspension Specific Ora-Plus/Ora-Sweet formulation adjusted to pH 7; reported potency 60 days at 5°C or 25°C protected from light. Not the monohydrate-mass recipe.	Oral Liquid	1 mg / mL	PO

Monitoring and Administration

Monitor ECG in patients at risk. Injectable cisapride requires validated sterile compounding.

A 1 mg/mL injection is described using 0.104 g monohydrate, 20 mL 6% tartaric acid and sterile water to final 100 mL; refrigerate protected from light and use within 14 days.

The described 10 mg/mL oral suspension uses 300 mg cisapride monohydrate, 15 mL Ora-Plus and sufficient Ora-Sweet to a final 30 mL. Reported stability is 30 days refrigerated; the monohydrate mass basis is retained separately from anhydrous cisapride.