Maropitant
(2S,3S)-2-benzhydryl-N-(5-tert-butyl-2methoxybenzyl) quinuclidin-3-amine citrate
Also known as: Cerenia · Prevomax · Vetemex · CJ-11,972 · Maropitant citrate
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Prevention of acute vomiting | 1 mg/kg | SC | q24h | up to 5 consecutive days | 🌎 NA |
| Prevention of acute vomiting | 2 mg/kg | PO | q24h | up to 5 consecutive days | 🌎 NA |
| Treatment of acute vomiting | 1 mg/kg | SC | q24h | up to 5 consecutive days | 🌎 NA |
| Prevention of vomiting due to motion sickness | 8 mg/kg (minimum dose) | PO | q24h | up to 2 consecutive days | 🌎 NA |
| Treatment and prevention of vomiting (including chemotherapy) | Dose not specified in text | PO/SC/IV | Not specified (duration of activity is 24 hours) | Up to 5 days | 🌍 EU |
| Motion sickness | Dose not specified in text | PO/SC/IV | Not specified | Up to 2 days | 🌍 EU |
- Prevention of acute vomiting: Given at least one hour prior to anticipated emetogenic event
- Prevention of acute vomiting: Given at least two hours prior to anticipated emetogenic event
- Treatment of acute vomiting: If a longer duration of therapy is needed, a 48 hour washout period is recommended due to accumulation of the drug.
- Prevention of vomiting due to motion sickness: Given at least two hours prior to travel. If a longer duration of therapy is needed, a 72 hour washout period is recommended.
- Treatment and prevention of vomiting (including chemotherapy): Repeat treatment at a lower dose may be adequate in some individuals. If longer periods of treatment are required, a 72-hour interval is recommended between courses.
- Motion sickness: Not all preparations are specifically licensed for this purpose.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| As an antiemetic | 1 mg/kg | SC or PO | Unknown | — | 🌎 NA |
| As an antiemetic | 0.5-1 mg/kg | SC | once daily | up to 5 days | 🌎 NA |
| Treatment of vomiting | Dose not specified in text | SC/IV | Not specified | Not specified | 🌍 EU |
- As an antiemetic: Based on pharmacokinetic study
- Treatment of vomiting: Treatment by injection is recommended for frequent vomiting. Very high doses may cause haemolysis.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Maropitant citrate (Cerenia®) is a highly effective, FDA-approved neurokinin-1 (NK-1) receptor antagonist used primarily as an antiemetic in veterinary medicine.
- Broad-Spectrum Antiemetic: Effectively blocks both peripheral and centrally mediated vomiting triggered by various stimuli (e.g., chemotherapy, apomorphine, gastrointestinal irritation).
- Analgesic Properties: Beyond emesis control, maropitant provides visceral analgesia and has been shown to significantly reduce the minimum alveolar concentration (MAC) requirements for inhalant anesthetics like sevoflurane.
- Species Use: Approved for dogs (≥16 weeks for general use, though caution is advised in puppies <11 weeks), and widely used extra-label in cats with excellent tolerability.
- Clinical Pearl: While it does not affect gastric emptying times, it can decrease small intestine contraction pressure patterns.
Mechanism of action
Maropitant exerts its effects by acting as a potent and selective antagonist at the neurokinin-1 (NK-1) receptors in the central nervous system (specifically the emetic center and chemoreceptor trigger zone).
- Substance P Inhibition: It competitively binds to NK-1 receptors, blocking the binding of Substance P, a key neuropeptide/neurotransmitter involved in the emetic pathway.
- Dual Action: Because Substance P is the final common pathway for vomiting, maropitant effectively suppresses emesis triggered by both central and peripheral stimuli.
- Pain Modulation: Substance P is also heavily involved in nociception; blocking its receptors in the visceral pathways provides significant visceral pain relief.
Safety & warnings
Contraindications
- Puppies less than 11 weeks old (due to risk of bone marrow hypoplasia)
- Suspected gastrointestinal obstruction
- Suspected gastrointestinal perforation
- Use for longer than 48 hours without a definitive diagnosis
Adverse effects
- Pre-travel vomiting (especially at higher motion sickness doses)
- Hypersalivation
- Pain or swelling at the subcutaneous injection site
- Diarrhea
- Anorexia
- Localized injection site reactions (cats)
- Transient pain reaction during injection (very common, especially in cats)
- Haemolysis (at very high doses in cats)
Precautions
Use with caution in dogs with hepatic dysfunction as maropitant is hepatically metabolized. Use with caution in puppies less than 11 weeks old due to a higher frequency and severity of bone marrow hypoplasia. The safe use of maropitant has not been evaluated in breeding, pregnant, or lactating dogs; use only following a benefit/risk assessment.
Drug interactions
Use with caution; maropitant is highly protein-bound (99.5%) and could theoretically compete for binding sites, though clinical significance is undetermined.
Maropitant has an affinity for calcium-channels; concurrent use should be avoided.
Maropitant is highly bound to plasma proteins and may compete with other highly bound drugs, potentially altering free drug concentrations.
Monitoring
- Clinical efficacy (decreased episodes of vomiting)
- Adverse effects (e.g., injection site pain, hypersalivation)
- Resolution of vomiting
- Liver function (in patients with pre-existing hepatic disease)
- Signs of gastrointestinal obstruction or perforation
Pharmacokinetics
Half-life
Absorption
Rapidly absorbed after PO & SC administration. Bioavailability in dogs: 24% (2 mg/kg PO), 37% (8 mg/kg PO), and 91% (1 mg/kg SC). Feeding status does not affect bioavailability. In cats, bioavailability is ~50% (PO) and 100+% (SC).
Distribution
Plasma protein binding is very high (99.5%).
Metabolism
Hepatic metabolism involves two cytochrome P450 enzymes: CYP2D15 (low capacity, high affinity) and CYP3A12 (high capacity, low affinity). The major pharmacologically active metabolite is CJ-18,518.
Elimination
Eliminated primarily by the liver. Urinary recovery of maropitant and its major metabolite is minimal (<1%).
Overdose
Maropitant has a wide margin of safety.
- Dogs: Tolerance has been confirmed at doses up to 3 times the recommended oral dose (8 mg/kg) for 3 times longer than the maximum duration.
- High-Dose Toxicity (20 mg/kg/day in dogs): Can cause emesis, significant body weight loss (8-15%), ECG changes (slight increases in P-R interval, P wave duration, and QRS amplitude), slightly lower serum albumin, and increased adrenal weights.
- Rodent Studies: Doses up to 30-100 mg/kg PO caused decreased activity, irregular/labored respiration, ataxia, and tremors.
Available products
Formulations
- Oral tablets
- 10 mg/ml injectable solution
- 16 mg oral tablet
- 24 mg oral tablet
- 160 mg oral tablet
Veterinary
- Maropitant Citrate Injectable Solution: 10 mg/mL in 20 mL multidose vials (Cerenia®)
- Maropitant Citrate Oral Tablets: 16 mg, 24 mg, 60 mg, and 160 mg in blister packs (Cerenia®)
- Cerenia 10 mg/ml solution for injection
- Cerenia 16 mg, 24 mg, 60 mg, 160 mg tablets
- Prevomax 10 mg/ml solution for injection
- Vetemex 10 mg/ml solution for injection
Regulatory status
POM-V classification
POM-V classification
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Injectable solution: Store at controlled room temperature 20-25°C (68-77°F). Must be used within 28 days of first vial puncture. Tablets: Packaged in foil to protect from moisture uptake; keep in blister packs until use. Halved tablets show no loss of potency for 48 hours.
Client information
Important Administration Note: Tablets should not be tightly wrapped or embedded in food/snacks (like pill pockets or cheese) as this may delay the dissolution and absorption of the tablet.
- Fasting: Avoid prolonged fasting before administration of tablets.
- Motion Sickness: To minimize the occurrence of pre-trip vomiting caused by the medication itself, feed your pet a small meal or snack one hour before administering the motion sickness dose.
- Injection Site: If your pet received a subcutaneous injection, mild swelling or pain at the injection site may occur. (Clinical pearl: Veterinarians often refrigerate the injectable solution, which significantly reduces stinging upon injection).
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.