Domperidone

Overview

Domperidone is a dopamine (D2) receptor antagonist used as an antiemetic in dogs and cats. It has a mechanism of action similar to metoclopramide but differs in that it does not readily cross the blood–brain barrier, resulting in fewer central nervous system adverse effects.

It is primarily used for the management of vomiting, although other veterinary antiemetics are more commonly preferred due to greater clinical experience. In dogs, domperidone has also been used in specific preventive protocols for canine leishmaniosis due to its immunomodulatory effects.

Mechanism of Action (MOA): Domperidone blocks peripheral dopamine (D2) receptors, leading to inhibition of the emetic pathway and reduction of nausea and vomiting. It also enhances gastrointestinal motility in some species, although its prokinetic effect in dogs is inconsistent. Additionally, it may stimulate prolactin release and enhance cell-mediated immune responses.

Indications

Domperidone is used in dogs and cats primarily as an antiemetic for the control of vomiting. However, it is less commonly used compared to other veterinary antiemetics with more established efficacy and clinical experience.

• Vomiting control: Used to manage nausea and vomiting, particularly when other agents are unavailable or not suitable.
• Alternative antiemetic option: May be considered as an alternative to more commonly used drugs such as maropitant, metoclopramide, or ondansetron.
• Leishmaniosis prevention (dogs only): Used as part of a strategic treatment protocol to reduce the risk of developing clinical canine leishmaniosis in high-prevalence areas.

Dosage (Reference)

Dog

In dogs, domperidone is administered orally for vomiting control or as part of a preventive protocol for leishmaniosis. Dosing depends on the indication and should be followed consistently.

Cat

In cats, domperidone is used for the control of vomiting with a fixed oral dosing regimen.

Warnings & Precautions

Domperidone should be used cautiously in dogs and cats due to limited veterinary data and potential for gastrointestinal, neurologic, and cardiovascular effects. Careful patient selection is recommended.

• Contraindications: Do not use in patients with intestinal obstruction or perforation, or in those with severe hepatic impairment.
• Limited veterinary data: There is relatively little clinical information available in dogs and cats; monitor patients closely during use.
• Gastrointestinal effects: May cause delayed gastric emptying (gastroparesis) in dogs despite prokinetic effects reported in other species.
• Endocrine effects: Increases prolactin levels, which may result in galactorrhea.
• Cardiac considerations: Although specific veterinary data are limited, caution is advised in patients at risk of cardiac conduction abnormalities.
• MDR1 mutation (dogs): Use with caution in susceptible breeds (e.g., collies) due to potential increased sensitivity.
• Use in cats: May cause dose-dependent behavioral changes (e.g., excitement, aggression) and motor impairment.

Drug Interactions

Clinically significant interactions with domperidone are primarily related to its potential effects on cardiac conduction and risk of arrhythmias. Concurrent use with certain medications should be avoided.

• Class IA and Class III antiarrhythmics (e.g., amiodarone, sotalol): Concurrent use is contraindicated due to increased risk of QT prolongation and serious cardiac arrhythmias.
• Macrolide antibiotics (e.g., erythromycin): Should not be used together due to increased risk of cardiac conduction disturbances.
• Cisapride: Concurrent administration is contraindicated due to additive effects on QT prolongation and increased risk of arrhythmias.

Side Effects & Overdose

Side Effects

Adverse effects of domperidone in dogs and cats are not extensively documented, but available data suggest gastrointestinal, endocrine, and neurologic effects may occur.

• Gastrointestinal effects: May cause gastroparesis in dogs.
• Endocrine effects: Increased prolactin levels may lead to galactorrhea.
• Behavioral changes (cats): Dose-dependent excitement or aggression may occur.
• Motor impairment (cats): May cause coordination abnormalities or altered movement.

Overdose

Information on overdose in dogs and cats is limited, but excessive dosing may increase the likelihood and severity of known adverse effects.

• Exaggerated adverse effects: Increased risk of gastrointestinal, neurologic, and behavioral signs.
• Cardiac risk: Potential for cardiac conduction abnormalities based on known effects in other species.
• Management: Discontinue the drug and provide supportive care with close monitoring.

Key Notes

Practical clinical considerations for the use of domperidone in dogs and cats:

• Peripheral action: Does not readily cross the blood–brain barrier, resulting in fewer central nervous system effects compared to other dopamine antagonists.
• Variable prokinetic effect: Unlike in humans, its gastrointestinal motility effects in dogs are inconsistent and should not be relied upon.
• Formulation flexibility: Available as tablets and oral suspension, allowing easier dosing across different patient sizes.
• Limited clinical use: Less commonly used in veterinary medicine due to availability of more established antiemetics.
• Immunomodulatory role (dogs): May enhance cell-mediated immune responses and is used in specific preventive protocols.