Cerenia (maropitant citrate) is an anti-vomiting medicine, and in cats the label is narrower than most people expect. In the US, the version approved for cats is the injection: 1 mg per kg of body weight, given by your vet team once a day for up to 5 days, in cats 4 months and older. Cerenia tablets are labeled for dogs only, so when a vet sends a cat home with tablets, that is an extra-label choice they make for that cat.
Below is a dosage chart by weight with the source for every number, a calculator, and what to watch for once your cat has had a dose.
Cerenia for Cats Dosage Chart
For information only. These are typical published dose ranges, not a prescription and not medically verified for your pet. Your veterinarian sets the dose after examining your pet. Never start, stop or change a medicine without their OK.
Cat | Use | Dose per kg | Dose per lb | How often | Route | Status | Source |
|---|---|---|---|---|---|---|---|
Cat | Treatment of vomiting (injection, cats 4 months and older) | 1 mg/kg | 0.45 mg/lb | Once every 24 hours, for up to 5 days in a row | Injection under the skin or into a vein, given by your vet team | FDA-approved label | |
Cat | Nausea and vomiting (tablets by mouth, extra-label) | 1 to 2 mg/kg | 0.45 to 0.91 mg/lb | Once every 24 hours; your vet sets how many days | By mouth | Extra-label: tablets are labeled for dogs only | Hickman et al., 2008 (1 mg/kg); ISFM feline kidney disease guidelines, 2016 (2 mg/kg) |
Dose calculator · Cerenia (maropitant citrate)
Cerenia for cats dose calculator
Not a prescription. For information only. These are typical published dose ranges, not a prescription and not medically verified for your pet. Your veterinarian sets the dose after examining your pet. Never start, stop or change a medicine without their OK.
Only give what your vet prescribed.
All doses in this calculator
| Pet | Use | Typical dose | How often | Route | Source |
|---|---|---|---|---|---|
| Cat | Treatment of vomiting (injection, cats 4 months and older) | 1 mg per kg (0.45 mg per lb)FDA-approved label dose. Your vet team gives this injection; it is not given at home. | once every 24 hours, for up to 5 days in a row | injection under the skin or into a vein, given by your vet team | Cerenia Injectable Solution, US label (DailyMed) |
| Cat | Nausea and vomiting (tablets by mouth, extra-label) | 1 to 2 mg per kg (0.45 to 0.91 mg per lb)Extra-label: Cerenia tablets are labeled for dogs only. The smallest tablet is 16 mg, so your vet decides how to split it or whether to compound it. | once every 24 hours; your vet sets how many days | by mouth | Hickman et al., 2008 (1 mg/kg); ISFM feline kidney disease guidelines, 2016 (2 mg/kg) |
Only give what your vet prescribed, at the dose they set. The two published sources for the tablet range do not agree on a single number, so the chart shows both: 1 mg/kg from a laboratory study and 2 mg/kg from the feline kidney disease guidelines. Your vet picks the dose for your cat.
A few things the chart cannot show on its own:
- The label covers the injection only. The FDA approved Cerenia for dogs in 2007 and added cats in May 2012, for the injectable solution only (FDA approval summary). Every maropitant tablet label we checked on DailyMed lists dogs only, and the Cerenia tablet label says "for oral use in dogs only". "Extra-label" (off-label) means a vet uses an approved drug in a way the label does not list. VCA Animal Hospitals notes that giving the tablets to cats for nausea and vomiting is exactly that.
- Tablets are sized for dogs. The smallest Cerenia tablet is 16 mg. For a typical cat, a dose in the chart's range is a fraction of that, so your vet decides how to split it or whether to have it compounded into a smaller form. In a kidney disease trial at Colorado State University, the cats got maropitant compounded into small capsules (Quimby et al., 2015).
- How long to give it is a vet decision. The label stops the injection at 5 days in a row and says a cat that keeps vomiting should be re-examined. In cats with chronic kidney disease, a daily oral course for 2 weeks reduced vomiting in a placebo-controlled trial (Quimby et al., 2015). Longer daily use is something your vet weighs for your cat.
If your cat has eaten extra tablets or you think it got a double dose, call your vet or a poison line now: ASPCA Animal Poison Control (888) 426-4435 or Pet Poison Helpline (855) 764-7661.
What Is Cerenia Used for in Cats?
Cerenia blocks the signal that makes a cat vomit and feel queasy. The US label approves the injection for the treatment of vomiting in cats. In the field study behind that approval, the cats had vomiting linked to conditions including gastroenteritis, gastritis, pancreatitis, inflammatory bowel disease, cancer and hepatic lipidosis (fatty liver). In the first 24 hours, 1.8% of the cats given Cerenia vomited, compared with 18.5% of the cats given a placebo.
Vets also use it off the label in a few common situations:
- Kidney disease. Nausea and poor appetite are common in cats with chronic kidney disease. The International Society of Feline Medicine lists maropitant among the drugs to consider, and the Colorado State trial found it cut vomiting in cats with stage 2 or 3 kidney disease. It did not change their appetite scores or weight in that trial.
- Before sedation. Some sedatives and opioids make cats vomit. In a Cornell study of 98 healthy cats, an oral dose given about 18 hours before sedation cut vomiting from 40% of cats to 4% (Martin-Flores et al., 2016).
- Motion sickness. This is a labeled use in dogs, not in cats, in either the US or the UK. A laboratory study found maropitant prevented motion-induced vomiting in cats (Hickman et al., 2008), but whether to use it before a car trip is your vet's call.
Whatever the reason, stopping the vomiting does not fix what is causing it. The label says the underlying cause should be found and treated, and the UK label warns that vomiting can come from serious problems such as a blocked intestine. A cat that is throwing up or has stopped eating needs a vet visit to find out why, and that is why Cerenia is prescription only.
Injection and Tablets: The Two Forms
Cerenia Injectable Solution is a clear liquid with 10 mg of maropitant in each mL, supplied in 20 mL vials. Your vet team gives it under the skin (subcutaneously) or slowly into a vein over 1 to 2 minutes. This is the form approved for cats, and it is the practical choice for a cat that is vomiting too much to keep a pill down.
Cerenia tablets are peach-colored, oval and scored down the middle, stamped "MPT" and the strength: 16, 24, 60 or 160 mg. They are labeled for dogs. Vets prescribe them for cats extra-label, for example so treatment can continue at home. The same active ingredient is also sold under other names, such as Emeprev, and as generic maropitant.
How Fast Does Cerenia Work?
Expect it to start working within about 1 to 2 hours (VCA Animal Hospitals). One dose lasts about 24 hours, which is why it is given once a day. In a laboratory study, the effect of a single dose lasted the full 24 hours in cats (Hickman et al., 2008).
Kittens clear the drug faster than adult cats. In the label's studies, the average half-life was 7.83 hours in kittens 4 to 7 months old and 17.2 hours in adults. The drug also accumulates with repeated doses: after one injection a day for 5 days, the label reports an accumulation of 250%.
Side Effects of Cerenia in Cats
The side effect you are most likely to see happens at the clinic: the injection stings. In the US field study, about 1 in 3 cats given Cerenia objected to the injection: they pulled away and cried out, and some also hissed and scratched. The label notes that injecting the product cold may reduce the sting.
Other effects in that study each affected fewer than 3 cats in 100:
- Dehydration
- Fever
- Lethargy (low energy)
- Not eating
- Blood in the urine
- Drooling
After approval, owners and vets reported these to the manufacturer and FDA, listed from most to least often reported: depression or lethargy, not eating, drooling, pain or crying out at the injection, trouble breathing, wobbly walking, fever, lying down and not getting up, vomiting, panting, seizures and muscle tremors. Deaths have been reported too. These reports cannot show how often each one happens or prove the drug caused it, and the UK label rates allergic-type reactions, lethargy and nerve signs as very rare.
When to Call Your Vet
Call your vet or an emergency clinic now if your cat:
- Has trouble breathing, or its face or head swells
- Has a seizure, collapses or cannot stand
- May have taken more than the prescribed dose (also call ASPCA Animal Poison Control at (888) 426-4435 or Pet Poison Helpline at (855) 764-7661)
See your vet soon if your cat:
- Keeps vomiting after a dose
- Is drooling, very sleepy or wobbly
- Still is not eating
In a sick cat, not eating is a reason to call the vet. Poor appetite in cats with ongoing illness can lead to malnutrition, which is why feline specialists treat it as something to manage actively (ISFM).
Cats That Should Not Get Cerenia, or Need Extra Care
Your vet weighs these before prescribing:
- Kittens. The US label approves the injection from 4 months of age. The UK label says safety has not been established under 16 weeks.
- A possible blockage or poisoning. The drug has not been tested in cats with a gastrointestinal obstruction or that have eaten a toxin. Stopping the vomiting could hide how sick the cat is.
- Liver disease. Cats break maropitant down in the liver, so the label says to use it with caution in cats with liver disease. That is a "your vet decides" point, not an automatic no.
- Heart disease. The UK label adds caution for animals with heart disease.
- Pregnant, nursing or breeding cats. Safety has not been evaluated.
Cerenia Drug Interactions
Cerenia is not free of interactions, so tell your vet about every medicine and supplement your cat gets.
- Other highly protein-bound drugs. Maropitant binds tightly to proteins in the blood and could compete with drugs that do the same. The label names NSAIDs (anti-inflammatory pain relievers), heart medicines, anticonvulsants and behavior medicines.
- Calcium-channel blockers. The UK label says not to combine Cerenia with calcium-channel blockers, because maropitant also binds to calcium channels. The US label does not mention this. If your cat takes amlodipine for high blood pressure, make sure your vet knows.
- Some antibiotics, antifungals and phenobarbital. VCA lists chloramphenicol, phenobarbital, erythromycin, ketoconazole and itraconazole as drugs to use with caution alongside maropitant.
What If You Miss a Dose?
Give it when you remember, then wait the full interval your vet set before the next one. Never give two doses at once or an extra dose to catch up (VCA). If the next dose is almost due, call your vet and ask which to do.
How to Store Cerenia
- Tablets: at room temperature, 68 to 77°F (20 to 25°C). Keep each tablet in its blister pack until you give it.
- Injection: at or below 86°F (30°C) until the vial is opened. Once the stopper has been punctured, the vial goes in the fridge at 36 to 46°F (2 to 8°C) and is used within 90 days.
Keep both out of reach of children and pets. The tablet label also warns that maropitant irritates the eyes and can cause skin reactions in some people, and it says to wash your hands with soap and water after giving a tablet.
How Does Cerenia Work?
When a cat's body detects something wrong, such as an irritated stomach, toxins building up in the blood from kidney disease, or a drug that triggers nausea, the signal travels to a cluster of nerve centers in the brainstem that controls vomiting. One of the key messengers in that circuit is a molecule called substance P, which acts on NK1 (neurokinin-1) receptors.
Maropitant blocks those NK1 receptors. With substance P shut out, the vomiting center does not get the message, so the drug works against vomiting from many different causes, both from the gut and from the bloodstream (Merck Veterinary Manual).
That broad action is the drug's strength. It is also why Cerenia can quiet a cat that still has a serious problem underneath.
Questions to Ask Your Vet
- What do you think is making my cat vomit, and what tests do we need?
- Is this the injection only, or tablets at home too? How many days?
- How should I split or give the tablet, and with or without food?
- Could any of my cat's other medicines interact with Cerenia?
- Which signs mean I should call you right away?
For dogs, the label and the doses are different: see our guide to Cerenia for dogs.
Originally written by Dr. Catharina Hjorth. Updated by the I Love Veterinary editorial team.
Sources
- Zoetis: Cerenia (maropitant citrate) Injectable Solution, US label (DailyMed)
- Zoetis: Cerenia (maropitant citrate) Tablets, US label (DailyMed)
- US FDA: Freedom of Information summary, supplemental approval of NADA 141-263 for the treatment of vomiting in cats (May 16, 2012)
- 21 CFR 522.1315, Maropitant (Electronic Code of Federal Regulations)
- UK Veterinary Medicines Directorate: Cerenia 10 mg/ml solution for injection for dogs and cats, product information
- Merck Veterinary Manual: Drugs Used to Control or Stimulate Vomiting in Monogastric Animals
- Sparkes et al., 2016, Journal of Feline Medicine and Surgery: ISFM Consensus Guidelines on the Diagnosis and Management of Feline Chronic Kidney Disease
- Hickman et al., 2008, Journal of Veterinary Pharmacology and Therapeutics: Safety, pharmacokinetics and use of maropitant for the prevention of emesis and motion sickness in cats
- Quimby et al., 2015, Journal of Feline Medicine and Surgery: Chronic use of maropitant for vomiting and inappetence in cats with chronic kidney disease
- Martin-Flores et al., 2016, Journal of Feline Medicine and Surgery: Evaluation of oral maropitant as an antiemetic in cats receiving morphine and dexmedetomidine
- VCA Animal Hospitals: Maropitant Citrate
This article is for general information and is not a substitute for advice from your veterinarian.
