Maropitant
Maropitant is a neurokinin-1 receptor antagonist used as an antiemetic in dogs and cats. It suppresses vomiting triggered through several central and peripheral pathways. Major applications include acute vomiting, prevention of selected drug-associated emesis and prevention of motion-associated vomiting in dogs. Oral and injectable products have different species-specific indications.
Group
NK1 antagonist antiemetic
Mechanism of Action
Maropitant competitively blocks neurokinin-1 receptors activated by substance P in brainstem emetic pathways. Substance P participates in integration of signals arriving from gastrointestinal afferents, circulating emetogenic stimuli and other central inputs. Blocking this signaling reduces activation of the coordinated vomiting response, allowing antiemetic activity against a broad range of triggers.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Vomiting | 1 mg/kg | SC, IV | Every 24 h | Dogs 2-7 months: maximum 5 consecutive days; older dogs may be treated until resolution according to the relevant formulation label. Age-dependent duration requires clinical selection. |
| Vomiting | 2 mg/kg | PO | Every 24 h | Dogs 2-7 months: maximum 5 consecutive days; older dogs may be treated until resolution according to the relevant label. |
| Motion sickness | 8 mg/kg | PO | Every 24 h | Up to 2 days; Do not use in: Dogs younger than 4 months; Oral tablets only; give at least 2 hours before travel with a small amount of food. |
| Opioid-associated vomiting prevention | 2–4 mg/kg | PO | Once | Before the planned anaesthetic/opioid procedure. |
| Opioid-associated vomiting prevention | 1 mg/kg | SC, IV | Once | Before the planned anaesthetic/opioid procedure. |
| Chronic bronchitis cough adjunct | 2 mg/kg | PO | Every 48 h | May reduce cough severity and frequency without treating airway inflammation. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Vomiting | 1 mg/kg | IV, SC, PO | Every 24 h | For highly emetic drugs, give at least 2-2.5 hours beforehand. |
| Kidney-disease-associated vomiting | 4 mg/animal | PO | Every 24 h | |
| Preanaesthetic vomiting prevention | Reference only | PO | 8 mg/cat orally 18 hours before the procedure is described with a 2.5 mg/kg example. Patient weight is not specified, so the example must not become a universal fixed dose. | |
| Preanaesthetic vomiting prevention | Reference only | SC | An injection 20 hours before anaesthesia is described without a separate amount in that protocol; the general feline antiemetic regimen is listed separately. | |
| Vomiting | 0.5–1 mg/kg | SC | Every 24 h | Up to 5 days; Additional short-course feline alternative. |
Indications
- Prevention or treatment of acute vomiting in dogs and treatment of vomiting in cats with a corresponding product.
- Prevention of motion-associated vomiting in dogs.
- Prevention or reduction of chemotherapy-associated vomiting in selected veterinary patients.
- Prevention of selected opioid- or alpha2-agonist-associated peri-anesthetic vomiting in dogs and cats.
- Symptomatic control of vomiting associated with gastrointestinal, renal or other disease while the underlying disorder is treated.
Contraindications
- Age and duration restrictions are regimen-specific.
- Assess underlying disease in persistent vomiting.
- Use cautiously with hepatic dysfunction.
Interactions
- Alkalinizing admixtures may precipitate injectable maropitant.
Adverse effects
- Injection pain, salivation and occasional muscle tremors
- High-dose equine exposure has caused bradycardia and heart block.
Toxicity
Reassess exposure and provide symptom-directed support for serious neurologic or cardiovascular reactions.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Cerenia maropitant 16 mg tablet | Tablet | 16 mg / tablet | PO |
| Cerenia maropitant 24 mg tablet | Tablet | 24 mg / tablet | PO |
| Cerenia maropitant 60 mg tablet | Tablet | 60 mg / tablet | PO |
| Cerenia maropitant 160 mg tablet | Tablet | 160 mg / tablet | PO |
| Maropitant 10 mg/mL injection Strength as maropitant, supplied as citrate. Refrigeration can reduce SC injection pain. | Injection | 10 mg / mL | SC, IV |
Monitoring and Administration
Refrigeration before SC injection can reduce injection pain; product vial-use period is 28 days after first puncture.
Give IV doses slowly using the actual product instructions.
For canine motion sickness, give tablets at least 2 hours before travel with a small snack rather than a full meal; injectable antiemetic doses are not interchangeable with the 8 mg/kg oral travel regimen.
For opioid-associated vomiting, administer before the opioid: at least 30 minutes for vomiting prevention, with 60 minutes suggested for nausea prevention.
Historical canine acute-vomiting protocols give SC maropitant at least 1 hour or oral tablets at least 2 hours before the emetic event. The older five-day course with 48-hour washout and motion-sickness 72-hour washout guidance is separate from later product-specific extended-treatment guidance; do not apply the older restriction as universal current labelling.