Is Cerenia Safe for Dogs? Uses, Side Effects and Dose Chart

If your vet just handed you a blister pack of Cerenia before a road trip, or gave your dog an injection after a bad night of vomiting, the first question is usually the same: is this stuff safe?

For most dogs, yes, when it is prescribed by a veterinarian and given at the label dose. Cerenia (maropitant citrate) is an FDA-approved anti-vomiting medicine for dogs, and in the field studies behind its label, side effects showed up in a minority of dogs. The safety comes with conditions, though: age limits that differ by use, a short list of dogs who need extra care, and a motion-sickness dose that is four times the everyday vomiting dose. Those details are below, along with the label's dosage chart and a weight calculator.

Is Cerenia Safe for Dogs?

Cerenia went through FDA review before approval, and its label publishes what happened to dogs in the field studies. That is a better answer to "is it safe" than any reassurance, so here are the numbers, each with the group of dogs it came from (Cerenia tablets label on DailyMed):

• Acute vomiting study (206 dogs given Cerenia tablets or injection for up to 5 days, 69 on placebo): diarrhea, bloody stool and loss of appetite were reported, but none of them more often than in the placebo group. Diarrhea, for example, showed up in 3.9% of treated dogs and 8.7% of placebo dogs. These were sick dogs, so some of what was reported came from the illness itself.
• US motion sickness studies (208 dogs given the higher motion-sickness dose once, 195 on placebo): drooling in 12.5% vs 9.7%, and vomiting in 5.3% vs 0%. The label notes this vomiting was not caused by motion sickness: a dose on an empty stomach can itself cause vomiting, which is why the label says to give the tablet with a small amount of food.
• European motion sickness study (107 dogs dosed for 2 days in a row, 106 on placebo): vomiting in 9% vs 4%, drowsiness or lethargy in 8% vs 1%, drooling in 5% vs 2%.

So Cerenia can make a dog a little sleepy, and the high travel dose can itself cause drooling or vomiting in a minority of dogs. Serious reactions are possible. After approval, owners and vets reported loss of appetite, lethargy, drooling, vomiting, diarrhea, trembling, wobbly walking, allergic reactions, weight loss and seizures, among others, and deaths have also been reported. The label is clear that these reports cannot show how often such events happen or whether the drug caused them. The injection has its own post-approval list, which includes pain at the injection site and allergic reactions with swelling of the face.

The label also says Cerenia lowers appetite and body weight in a dose-related way, and that the cause of the vomiting should always be found and treated. For most dogs, that last point is the bigger safety issue. Cerenia stops the vomiting, not the disease behind it.

Which Dogs Should Not Get Cerenia, or Need Extra Care

These come from the FDA labels for the tablets and the injection unless another source is named:

• Young puppies. Tablets for vomiting and the injection under the skin are labeled from 2 months of age. Tablets for motion sickness, and the injection into a vein, start at 4 months. In safety studies, puppies younger than 11 weeks given Cerenia showed reduced bone marrow cell counts more often and more severely than untreated puppies. This was not seen in puppies 16 weeks and older.
• Dogs that may have eaten something toxic. The label says safe use has not been evaluated in these dogs. In practice, a vet may want the poison out, not kept down, so never give a leftover tablet after a suspected poisoning. Call your vet or a poison line first.
• Dogs that may have a blockage in the gut. Also not evaluated. Stopping the vomiting can hide a swallowed toy or bone that needs surgery.
• Dogs with liver disease. Use with caution, because the liver breaks the drug down.
• Breeding, pregnant or nursing dogs. Safe use has not been evaluated.
• Dogs on other medicines. Cerenia binds strongly to blood proteins, so the label advises caution with other highly protein-bound drugs such as NSAID pain relievers, heart medicines, seizure medicines and behavior medicines. VCA Animal Hospitals lists chloramphenicol and erythromycin (both antibiotics), phenobarbital (a seizure medicine), ketoconazole and itraconazole (antifungals) and NSAIDs as drugs to use with caution alongside it (VCA). Tell your vet about every medicine, supplement and vitamin your dog gets.

VCA also advises caution in dogs with heart disease, which the US label does not mention. Your vet will weigh that for your dog.

What Cerenia Is and How It Works

Cerenia is the brand name of maropitant citrate, made by Zoetis. It is a prescription-only drug, so a veterinarian has to examine your dog and prescribe it. It comes in two forms:

• Tablets of 16, 24, 60 and 160 mg. They are peach colored, scored so they can be split in half, and labeled for dogs only.
• An injection of 10 mg per mL, which your veterinary team gives under the skin or into a vein. It is labeled for dogs and cats.

Vomiting is controlled by a group of nerve centers in the brainstem, often called the vomiting center. A messenger chemical called substance P is a key signal there. Maropitant blocks the receptor that substance P binds to (the NK1 receptor), so the "empty the stomach" signal cannot get through. Because it acts on that central step, it works against vomiting triggered from the brain, such as motion, and from the body, such as an inflamed gut (Cerenia tablets label). The Merck Veterinary Manual calls maropitant FDA-approved and the preferred drug for motion sickness in dogs (Merck). The injection was approved in 2007.

What Cerenia Is Used for in Dogs

The FDA labels cover three jobs in dogs:

1. Preventing and treating acute vomiting. Acute means sudden, as opposed to vomiting that has gone on for weeks. The cause can be anything from gastroenteritis to an infection such as parvovirus, pancreatitis or kidney failure. In a dog that is actively vomiting, the label recommends starting with the injection so the full dose stays down, then switching to tablets.
2. Preventing vomiting from motion sickness. This uses the tablets only, at a higher dose.
3. Preventing vomiting caused by chemotherapy or other medicines that often cause vomiting. This uses the injection, given once beforehand, in dogs 4 months and older.

In one label study, none of the dogs given the Cerenia injection before an opioid painkiller vomited, compared with 15 of 16 dogs given saline (Cerenia injection label).

How well does it work? In a study of motion-sick dogs taken on a one-hour car ride, 7% of dogs given Cerenia tablets 2 hours before vomited, compared with 55% of dogs given placebo. In a field study of dogs brought to vets with acute vomiting, 21.4% of treated dogs vomited during the study versus 50% of placebo dogs (Cerenia tablets label). Good results, but not a guarantee, and a dog that keeps vomiting on Cerenia needs to be seen again.

Vomiting is a symptom, not a diagnosis. A dog that vomits more than once, can't keep water down, or seems weak needs a vet visit to find out why, and dogs that vomit can dehydrate quickly.

Have a cat? The injection is approved for cats, but the tablets are not, so cats follow different rules. See Cerenia for cats.

Motion Sickness in Dogs

Car sickness in dogs works much like it does in people. Balance is tracked by the inner ear, the eyes, and the muscles and joints. In a moving car these send conflicting messages to the brain, which responds with a stress reaction that can end in nausea and vomiting. The NK1 receptors that Cerenia blocks play a major role in this in dogs (Merck).

Signs of motion sickness and nausea in dogs include:

• Drooling.
• Lip licking.
• Whining.
• Restlessness: panting, turning, circling or digging.
• Lethargy.
• Vomiting, and in severely affected dogs, diarrhea.

The signs usually stop once the car does. Some dogs learn to fear the car itself and show the same signs before it even moves. For those dogs, gradually getting them used to the car, or medicine for anxiety, may help more than an anti-vomiting drug alone. Ask your vet which applies to your dog.

Cerenia Dosage Chart for Dogs

Every number here comes from the FDA-approved labels for Cerenia tablets and Cerenia injectable solution. Only give what your vet prescribed, at the dose they set.

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.

A few things the chart doesn't show at a glance:

• The motion-sickness dose is four times the vomiting dose. A tablet prescribed for car rides is not the right amount for a stomach bug, and the other way round.
• The tablet doses are the label's minimums, and your vet sets the dose. Your vet picks whole or half tablets that come closest to it, so the amount your dog gets per kg is rarely exactly the number in the chart.
• The injection is not a substitute for the motion-sickness tablets. The label says the two should not be used interchangeably at the motion-sickness dose.

The tablets label prints these tablet tables for each use. Weights are as printed on the label.

Acute vomiting (2 mg/kg), dogs 2 months and older

Motion sickness (8 mg/kg), dogs 4 months and older

Source: Cerenia tablets label.

If the medicine doesn't seem to be working, don't give an extra tablet or a bigger dose. Call your vet.

How to Give Cerenia Tablets

• For car trips: the label says to give the tablet at least 2 hours before travel with a small amount of food, because a dose on an empty stomach can itself cause vomiting, but not to feed a full meal before the trip. VCA suggests a small meal about 3 hours before travel and the tablet about 2 hours before (VCA). Follow the timing your vet gives you.
• Don't wrap it too tightly. Hiding the tablet in a big wad of food can stop it from being absorbed properly (VCA).
• Wash your hands afterwards. The label warns that skin contact can cause allergic skin reactions in some people, and that the drug irritates the eyes. If it gets in your eyes, rinse with water for 15 minutes and get medical advice.
• Missed a dose? Give it when you remember, then wait the usual interval before the next one. Never give two doses together (VCA).

The injection is given by your veterinary team, not at home.

Side Effects and When to Call the Vet

Mention it to your vet: mild sleepiness, a smaller appetite for a day, or a little drooling after a dose.

Call your vet soon: vomiting that continues despite Cerenia, diarrhea, a dog that won't eat, or a dog that seems more tired than its illness explains. The label says any dog that keeps vomiting on treatment should be re-examined.

Call now or go to an emergency clinic: swelling of the face, trouble breathing, collapse, a seizure, or a dog that is very weak or can't stand. Allergic reactions, seizures and collapse are on the label's list of reported reactions.

If your dog got into the tablets, was given the wrong dose, or you think it ate something poisonous, call your vet straight away. If they are closed, call the ASPCA Animal Poison Control Center at (888) 426-4435 or the Pet Poison Helpline at (855) 764-7661.

Cerenia vs Dramamine

Dramamine (dimenhydrinate) is a human over-the-counter motion sickness medicine. It is an antihistamine, the same family as meclizine and diphenhydramine. According to the Merck Veterinary Manual, antihistamines can prevent motion sickness and reduce drooling, but they also sedate (Merck).

Sources: Cerenia tablets label; Merck Veterinary Manual.

Off-label means a drug is used in a way the FDA has not reviewed for that species or condition. Many drugs are used this way in veterinary medicine, and off-label does not mean dangerous or wrong (VCA). It does mean you should follow your vet's directions closely, since they may differ from the box. Never give a dog a human medicine on your own.

For car sickness, Merck names maropitant the preferred drug in dogs. Some dogs still need a different medicine, or help with fear of the car, so ask your vet what fits your dog.

How to Store Cerenia

• Tablets: at room temperature, 68-77 °F (20-25 °C), and brief swings to between 59 and 86 °F (15-30 °C) are allowed. VCA suggests keeping them in the blister pack until you need a dose (VCA).
• Injection (vet clinic): unopened vials at or below 86 °F (30 °C). Once the vial has been punctured, it goes in the fridge at 36-46 °F (2-8 °C) and must be used within 90 days (Cerenia injection label).

Keep all medicines out of reach of children and pets.

Originally written by Dr. Catharina Hjorth. Updated by the I Love Veterinary editorial team.

Sources

• DailyMed (Zoetis): Cerenia (maropitant citrate) Tablets, FDA-approved label, NADA 141-262
• DailyMed (Zoetis): Cerenia (maropitant citrate) Injectable Solution, FDA-approved label, NADA 141-263
• Merck Veterinary Manual: Motion Sickness in Animals
• Merck Veterinary Manual: Drugs Used for Motion Sickness in Dogs and Cats
• VCA Animal Hospitals: Maropitant Citrate
• ASPCA: Animal Poison Control Center
• Pet Poison Helpline

This article is for general information and is not a substitute for advice from your veterinarian.