Major Uses

Maropitant citrate is a strong anti-nausea medication for dogs and cats that treats acute vomiting associated with motion sickness and disease-related nausea. It works by mimicking the structure of a neurotransmitter called substance P.

Normally, when substance P binds to neurokinin receptors in the vomit center of the brain stem, it triggers vomiting. By mimicking substance P, maropitant citrate binds to the neurokinin receptors and prevents true substance P from obtaining access, thereby making stimulation of the vomit center extremely challenging.

Common Precautions

Side effects associated with proper use of maropitant are uncommon, but they may include drowsiness, drooling, diarrhea, and loss of appetite.

Side effects are more likely to occur and may be more serious when maropitant is taken in combination with other drugs that are highly blood protein-bound. Some drugs that may interact in this way with maropitant include non-steroidal anti-inflammatory drugs, phenobarbital, and thyroid hormone supplements. Maropitant may also interact with cardiac drugs, medications used to treat seizures, and other medications.

Maropitant citrate is not for use in puppies less than 8 weeks of age or in cats less than 16 weeks of age. This drug is not appropriate for animals suffering from liver disease, and its safety in pregnant and nursing animals is not known. This drug should be used cautiously in animals with gastrointestinal obstruction or toxin ingestion. Maropitant should not be wrapped in a treat that may cause upset stomach during administration. Fatty treats are a poor choice during treatment with this drug, as they decrease its effectiveness.

Maropitant citrate should not be used in animals with a known allergy or hypersensitivity to the drug. Any known or suspected overdose should be reported to a veterinarian right away.


Maropitant citrate should be stored at room temperature, away from heat and direct sunlight. It should be kept away from animals and children and should not ever be stored in the bathroom or above the kitchen sink. Maropitant injection must be used within 28 days of the first vial puncture.


Maropitant citrate is available as an injectable and as 16 mg, 24 mg, 60 mg, and 160 mg tablets.

To treat acute vomiting in dogs, injectable maropitant is typically dosed at 0.45 mg/lb (1.0 mg/kg) once daily. Oral maropitant is typically dosed at 0.9 mg/lb (2 mg/kg) by mouth once daily. To treat motion sickness in dogs, maropitant citrate is typically dosed at 3.6 mg/lb (8 mg/kg) once daily. Maropitant is used in 5-day courses. If the medication needs to be continued beyond 5 days, a day should be skipped between courses. Maropitant citrate can be given 2 days in a row to treat motion sickness.

Doses may vary in different species, when the drug is given by a different route or concurrently with other medications, and with regards to a patient's age, breed, and health status. A veterinarian's dosing instructions and/or those printed on the medication label should be followed closely.

If a dose of this medication is missed, it should be given as soon as possible. If it is almost time for the next dose, the missed dose should be skipped and the normal schedule resumed. It is important not to give two doses of this medication at once.

This information is for general reference only and should not be used for the diagnosis or treatment of any condition of your pet. It's intended as a general reference, this information may not include all possible uses, precautions, directions, reactions (including allergic), drug interactions, or withdrawal times. Always consult your local veterinarian and have your pet examined for any advice concerning the diagnosis and treatment of your pet, including which products and doses are most appropriate. Any trademarks are the property of their respective owners. VetDepot is not a pharmacy. All prescription products are dispensed by our Pharmacy Partner. Article last updated 2/2014.