Cerenia Nasal Drops and Injections for Cats

Name: Cerenia Nasal Drops and Injections for Cats
Creator: Dr. Zubair Khalid

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-10-03

Cerenia for cats nasal drops and injections are two ways veterinarians deliver the same active drug, maropitant citrate, to control vomiting and nausea. The injectable form is given by a veterinarian in the clinic, while the nasal drop form has been studied for treating upper respiratory signs in shelter cats. This article is educational and is not a substitute for veterinary diagnosis or treatment.

Quick Answer

Cerenia (maropitant citrate) is an anti-vomiting medicine approved for use in cats and dogs. The injectable form is given by a veterinarian, usually under the skin or into a muscle.
The nasal drop form is not a standard at-home product you buy at a pharmacy. In a shelter study, diluted maropitant was dripped into the nose twice daily for 7 days to reduce upper respiratory signs [1].
Never give your cat a human nausea drug or leftover Cerenia from another pet. The dose depends on your cat's weight and health, and only your veterinarian can set it.
A compounded transdermal gel has been studied as an option for vomiting cats, applied to the inner ear once daily for 5 days at 4 mg per cat [2]. This is not the same as the nasal or injectable forms.
Call your veterinarian or a poison control hotline right away if you think your cat received too much, or if you see severe weakness, tremors, or trouble breathing.

What Cerenia Is and What Veterinarians Use It For

Maropitant citrate is a prescription medicine sold under the brand name Cerenia. It is a neurokinin-1 (NK-1) receptor antagonist labeled for treating vomiting in dogs and cats [3]. In plain terms, it blocks a signal in the brain that triggers the vomit reflex.

Veterinarians use it for several reasons:

To stop acute vomiting from stomach upset, eating something irritating, or motion sickness
To prevent vomiting before surgery or after certain drugs that commonly cause nausea
To manage ongoing vomiting tied to kidney disease, pancreatitis, or other chronic conditions
To reduce nausea so a cat will eat and take other medicines

Cerenia comes as an injectable solution and as tablets. The injectable solution is the form most often used in the clinic because a vomiting cat may not keep a pill down. The nasal drop form is a different use of the same drug. In a 2025 shelter study, maropitant citrate 10 mg/ml was diluted 1:10 with sterile saline and given into the nose twice daily for 7 days to cats with naturally acquired upper respiratory disease [1]. That study looked at eye and nose signs, not vomiting.

If your cat has sneezing, eye discharge, or a runny nose, those signs overlap with many conditions. Our guide to Cat Coughing Sneezing can help you sort out what you are seeing before your appointment.

How Cerenia Works in Cats

Maropitant blocks NK-1 receptors in the brain's vomiting center. When those receptors are blocked, the signals that normally trigger nausea and vomiting cannot get through as easily.

One thing owners notice is that Cerenia can slow the gut. A study in healthy adult dogs found that a 1 mg/kg subcutaneous dose of maropitant significantly decreased the rate of peristalsis (the wave-like muscle contractions that move food along) in the stomach and jejunum, without significantly changing intestinal diameter or wall thickness [3]. This effect has been seen anecdotally in cats too, which is one reason veterinarians use the lowest effective dose and do not reach for Cerenia for every mild stomach upset.

For vomiting prevention, the evidence in cats is solid. A systematic review and meta-analysis of controlled feline studies found that maropitant reduced the risk of vomiting compared with control, with emesis occurring in 11 of 141 cats given maropitant versus 70 of 152 controls [4]. That is a large difference, and it supports why veterinarians reach for this drug so often.

Cerenia for Cats Nasal Drops: How They Are Used

The nasal drop form is the least familiar to most owners. Here is what the research actually shows.

In the shelter study, cats with upper respiratory disease were randomly assigned to receive either intranasal maropitant diluted in saline or plain saline, both given twice daily for 7 days [1]. The maropitant was prepared by diluting the 10 mg/ml injectable solution 1:10 with sterile 0.9% saline [1]. Disease severity was scored for conjunctivitis, eyelid spasms, eye discharge, and nasal discharge [1].

This matters because it tells you the nasal route is a real area of veterinary research, not a home remedy. It also tells you the solution is not something you mix yourself. The dilution, the dose, and the timing all come from a veterinarian.

What "how to" looks like in practice

If your veterinarian prescribes nasal drops, ask these questions at pickup:

How many drops go in each nostril?
How often, and for how many days?
Should I clean the nose first?
What if my cat sneezes it right back out?

Do not use the injectable Cerenia bottle as nose drops on your own. The concentrated solution is meant for injection, and the nasal study used a specific dilution [1]. Giving the wrong strength into the nose can irritate the lining or deliver an unpredictable amount.

Upper respiratory signs in cats can also come from asthma, which looks different and needs different treatment. If your cat is coughing or wheezing more than sneezing, read Feline Asthma: Inhaler Therapy and Technique.

Cerenia Injection for Cats: What to Expect

The injection is the form you will see most often at the clinic. A veterinarian or technician gives it under the skin (subcutaneously) or into a muscle. It works quickly, which is why it is used when a cat is actively vomiting and cannot hold down a pill.

You will not give this injection at home unless your veterinarian has specifically trained you and sent you home with supplies. Most owners bring the cat in for the injection and then switch to tablets or another plan once vomiting stops.

The transdermal option

Some compounding pharmacies make a transdermal gel from Cerenia tablets. In one study, eight cats with recent vomiting received compounded transdermal maropitant at 4 mg per cat once daily, applied to the inner ear for 5 days [2]. The gel was made by grinding Cerenia tablets, dissolving them in propylene glycol, and mixing them into a liposomal base [2].

This is a compounded product, which means it is not the same as the FDA-approved injectable or tablet. Compounded drugs vary in strength and absorption. If your veterinarian suggests a transdermal gel, ask where it is made and how the dose was set.

Dosing Basics: Who Decides and What to Do If You Miss a Dose

Your veterinarian calculates the dose from your cat's weight and health. Never use a dose meant for a dog, and never split a tablet based on guesswork.

For the nasal form, the study dose was maropitant citrate 10 mg/ml diluted 1:10 with sterile saline, given twice daily for 7 days [1]. That is a research protocol, not a prescription for your cat. Your veterinarian will tell you the exact volume and schedule.

For the transdermal form, the studied dose was 4 mg per cat once daily for 5 days [2]. Again, this is a study protocol. Your cat's dose may differ.

If you miss a dose

Give the next dose at the normal time. Do not double up.
If you are not sure whether the dose went in (a cat sneezed it out, or you are not sure the gel absorbed), call your veterinarian before repeating it.
Keep a simple log of times and doses so you can report accurately.

Side Effects: Common and Serious

Side effect	How common or serious	What to do
Sleepiness or mild sedation	Common, usually mild	Let your cat rest. Call your vet if it lasts more than a day or seems excessive.
Drooling or lip smacking after a pill	Common, not dangerous	Offer a small drink of water. Ask your vet about giving it with a tiny amount of food if allowed.
Vomiting that continues despite treatment	Serious, means the drug is not working or the cause is different	Call your veterinarian the same day.
Slow gut movement (decreased peristalsis)	Seen in a dog study at 1 mg/kg subcutaneous [3]	Report any bloating, no appetite, or no bowel movement to your vet.
Nasal irritation, sneezing after nasal drops	Possible with nasal use	Call your vet if your cat seems painful or the nose bleeds.
Severe weakness, tremors, trouble breathing	Rare but an emergency	Go to an emergency clinic now.

Most cats tolerate Cerenia well. The most reliable sign that something is wrong is not a side effect at all. It is vomiting that does not stop, or a cat that gets worse instead of better.

Who Should Not Take It and Drug Interactions

Cerenia is not right for every cat. Tell your veterinarian about all medicines, supplements, and conditions before treatment starts.

Cats that may need extra caution include:

Cats with liver disease, because the liver processes maropitant
Cats with known sensitivity to maropitant
Very young kittens, unless your veterinarian specifically recommends it
Pregnant or nursing cats, where safety has not been well established

Drug interactions matter too. Because maropitant can slow gut movement [3], it may change how quickly other oral medicines are absorbed. If your cat takes heart medication, seizure medication, or anything with a narrow safety margin, your veterinarian needs to know.

Do not combine Cerenia with other anti-nausea drugs unless your veterinarian directs it. A systematic review of feline antiemetic strategies looked at maropitant, ondansetron, and metoclopramide, and the authors noted that evidence comparing protocols is limited by differences in triggers, timing, and outcomes [4]. In other words, more drugs is not automatically better.

Overdose and When to Call for Help

If you think your cat got too much Cerenia, act right away. Do not wait to see if signs appear.

Call your veterinarian or an emergency clinic first. If they are closed, call a poison control hotline for animals. Have the bottle or package with you so you can read the strength and the amount given.

Signs that need emergency care include:

Extreme sleepiness that you cannot wake your cat from
Tremors, twitching, or unsteady walking
Trouble breathing
Collapse
Repeated vomiting that will not stop

Bring the medicine container with you. The veterinarian will want to know the concentration, how much was given, and when.

Limitations and When to Contact a Veterinarian

No article can tell you what is wrong with your specific cat. Individual cases need a veterinarian who can examine your cat, run tests if needed, and set a dose.

Use these timing rules:

Call the same day if:

Your cat has vomited more than twice in 24 hours
Your cat refuses food or water for more than 12 hours
Nasal drops or injections seem to be causing pain, bleeding, or distress
Your cat is on Cerenia and gets worse instead of better

Go to an emergency clinic now if:

Your cat is struggling to breathe or breathing with an open mouth
Your cat collapses or cannot stand
You see tremors or seizures
You suspect an overdose

Schedule a routine visit if:

Vomiting comes and goes over weeks
Your cat has chronic nasal discharge or sneezing
You want to discuss whether Cerenia is right for long-term use

If your cat has ongoing sneezing and nasal discharge, our guide Cat Sneezing and Nasal Discharge: When to See a Vet walks through the signs that need a closer look. For cats with a confirmed upper respiratory infection, Cat Upper Respiratory Infection Treatment covers what treatment usually involves.

Frequently Asked Questions

Can I give my cat Cerenia nasal drops at home?

Only if your veterinarian prescribes them and shows you how. The nasal form used in research was a specific dilution of the injectable solution, not the full-strength bottle [1]. Giving the wrong strength can irritate the nose or deliver an unpredictable dose.

Is the injection better than the pill for vomiting?

The injection works faster and is used when a cat cannot keep a pill down. Once vomiting stops, many veterinarians switch to tablets or another plan. Your veterinarian will pick the form based on how sick your cat is.

Can Cerenia be used for sneezing and nasal discharge?

It has been studied for upper respiratory signs in shelter cats, given as diluted nasal drops twice daily for 7 days [1]. That does not mean it is a standard treatment for every sneezing cat. Your veterinarian will decide whether it fits your cat's case.

What if my cat vomits after getting Cerenia?

Call your veterinarian the same day. Ongoing vomiting can mean the dose is too low, the cause is different, or something else is going on. Do not give a second dose on your own.

Is compounded transdermal Cerenia safe?

It has been studied in a small group of cats at 4 mg per cat once daily for 5 days, applied to the inner ear [2]. Compounded products can vary in strength, so ask your veterinarian where it is made and how the dose was set.

References

Effects of intranasal maropitant on clinical signs of naturally acquired upper respiratory disease in shelter cats. Journal of feline medicine and surgery, 2025.
Evaluation of the efficacy of transdermal administration of maropitant in managing vomiting in cats. Open veterinary journal, 2022.
Maropitant Citrate Administration Significantly Decreases the Rate of Peristalsis in the Stomach and Jejunum and Does Not Significantly Alter Intestinal Diameter or Intestinal Wall Thickness in Healthy Adult Dogs. Veterinary radiology & ultrasound : the official journal of the American College of Veterinary Radiology and the International Veterinary Radiology Association, 2026.
Receptor-Targeted Antiemetic Strategies in Cats: A Systematic Review and Intervention-Specific Meta-Analysis. Veterinary medicine and science, 2026.