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Product Info
How to Use
Customer Reviews
Product Info

What is Mirtazapine?

Mirtazapine was created to treat depression in humans, but was found to be very beneficial in stimulating appetite in pets. It is usually administered to pets suffering from conditions like renal failure and stomach disease. In addition, it aids with loss of appetite or nausea associated with cancer treatments. Mirtazapine is sold per tablet and requires a prescription from your veterinarian.


Cats and Dogs


  • Stimulates appetite in pets
  • Used as an anti-nausea for pets undergoing cancer treatments
  • Comes in a small tablet
  • Sold per tablet

How does Mirtazapine work?

Mirtazapine causes a side effect that stimulates appetite. It also has strong anti-nausea properties that block signals from the intestine and stomach that communicate with the vomit center of the brain.


Keep out of reach of children. Safety of Mirtazapine is unproven in pregnant and lactating pets.

Brand Name:

Mirtazapine (Vedco)

Generic Name:

Pancreatic Enzymes

What is the most important thing I should know about Mirtazapine?

Mirtazapine is used as an appetite stimulant for pets. It is extremely beneficial for pets that are suffering from a condition such as stomach disease, renal failure or other conditions that make pets feel queasy and lose their appetite. It is also prescribed to pets that are undergoing chemotherapy treatments, since an unsettled stomach is commonly attributed to chemotherapy. Mirtazapine requires a prescription from a veterinarian.

What should I discuss with my veterinarian before giving Mirtazapine to my pet?

Tell your veterinarian if your pet is currently on any other medications.

How should Mirtazapine be given?

Generally, Mirtazapine is given once a day to dogs, and twice a week to cats. However, dosages vary by weight and by veterinarians' instructions so use accordingly.

What are the potential side effects of Mirtazapine?

One potential yet rare side effect is serotonin syndrome. It is caused when the serotonin levels become elevated. This usually occurs when Mirtazapine is used as part of a combination of other serotonin-increasing medications. Monitor your pet with elevated heart rate, tremors, dilated pupils, difficulty breathing, fever or high blood pressure. Hyperactivity is also a sign in some dogs.

What happens if I miss giving a dose of Mirtazapine?

Give the missed dose as soon as you remember during the same day. However, if you don't remember until the next day, skip the dose you missed and give only the next regularly scheduled dose. Do not give a double dose of the medication.

What happens if I overdose my pet on Mirtazapine?

If you suspect that your pet has received an overdose of Mirtazapine, consult your veterinarian or emergency veterinary clinic immediately.

What should I avoid while giving Mirtazapine to my pet?

Mirtazapine should not be combined with other antidepressants.

What other drugs will affect Mirtazapine?

Mirtazapine may interact with other antidepressants. Tell your veterinarian if your pet is currently on any other medications.

How to Use

Mirtazapine Directions:

  • Generally, Mirtazapine is given once a day to dogs, and twice a week to cats. However, dosages vary by weight and by veterinarians instructions so use accordingly.
  • It is used to treat conditions where poor appetite and nausea go together.
  • It is also used to alleviate the nausea associated with chemotherapy when treating cancer.

It is important to find out the cause of the loss of appetite in your pet and treat the underlying condition and not just the symptoms.

All weights
Varies by weight, use according to your veterinarian.
All weights
Varies by weight, use according to your veterinarian.
Do not use!

Should be stored at room temperature. Keep away from moisture and heat.


Mirtazapine Ingredients:

Active Ingredients (per tablet)
Mirtazapine USP
15 mg
Customer Reviews
Mirtazapine is rated 4.8 out of 5 by 4.
Rated 5 out of 5 by from Has saved my life for 5+ months When I became ill with a mass in my stomach, the oncologist said I had a poor prognosis even with 'chemo' My appetite was down and my spine was boney; I had lost ~two pounds. I was a few days away from starving. My owner found a different vet, and treats me with Prednisone, Mirtazapine (for my appetite) and Mitrizine (Cerenia) for my nausea. I have gained weight, strength, and resumed jumping around on furniture. My owner hugs me a lot. Other advice: 1) Give Mitrizine 1/2 hr before other med(s), to protect my stomach before the other pills. 2) IMPORTANT: Administer meds in AM, or "I" will keep you awake all night, b/c cats are nocturnal, and the Pred further energizes me. 3) Mitrizine makes me foam at the mouth, so insert the dose into a salmon treat, get it in the back of my tongue, and squirt some water down my throat so you make sure I swallow it. Otherwise, I try to spit it out or slyly discard it.
Date published: 2015-07-04
Rated 5 out of 5 by from Saved my cat's life! My cat was at stage 4 Kidney disease.when the U of Minnesota pet hospital recommended this for his lack of appetite. He had lost a # and gained it right back after using this about twice a week. About every three to four days he starts to lose his appetite. I then give him (for his 9 # weight) 1/8 to 1/4 of a pill. That keeps him from getting too much. I just chip off a piece and hold his head back until he swallows it.He does get anxious and eyes dilated after 10 minutes but he is suddenly starved and eats happily for 3 to 4 days and is very affectionate. Don't be scared of the temporary howling...use small chip dose.
Date published: 2014-11-11
Rated 5 out of 5 by from My cat has lower intestional cancer and i was given this in a liquid form.. My cat hates the taste of this medicine, even though they made it chicken flavored he still does not like it at all and he makes himself drool excessively. Since taken this with his chemotherapy medicine he has started gaining weight. He actually eats like crazy after the medicine has kicked in and also no longer throws up. The one thing I do not like is that he gets a little anxious and his eyes become very dialated for at least 10 minutes, then he is back to himself. I love this product but feel bad having to give him any medicine at all but it has helped him 90%.
Date published: 2014-05-14
Rated 4 out of 5 by from Pretty good but a few side effects Seems to suppress nausea and it is helping my cat to eat more. But I wonder how good it is for her as it makes her hyper for at least the first 12 hours after giving it to her. And she meows a lot and seems restless. She has had 3 doses over the past week and a half...I may lengthen the time between doses...TBC
Date published: 2014-04-01
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My cat was prescribed mirtaxapine 15mg. Instead of cutting them in 4ths, I accidentally gave him the whole pill. The vet said he will get pretty loopy but should I be more worried??! 

Asked by: KSpend
In the event of overdose: Contact your veterinarian or veterinary emergency room.
Answered by: Cherley Petmeds Pro
Date published: 2017-10-03

I ordered the white pills but got the yellow ones. Is there any difference in efficacy?! I will tell you they are MUC harder to cut into eighths for my cat ....

Asked by: Carol
The only difference between them is the generic company that manufactured the medication. There is no difference if efficacy.
Answered by: Lisa M
Date published: 2017-09-19

Is there a preference of what time of day to give this medication and should it be given on an empty stomach?  How long after you give it should you give your dog food?  Thank you.

Asked by: Lucy
Thank you for your question. Generally, Mirtazapine is given once a day to dogs; however, dosages vary by weight and by veterinarians' instructions so use accordingly. Mirtazapine requires a prescription from a veterinarian so they should give you specific instructions suited for your dog.
Answered by: leanniejo
Date published: 2017-10-27

Is it okay for my dog to go on & off this medication? She was having a problem eating & once I gave her this pill she started eating again & I can take her off them but if she starts to not eat again can I put her back on them and continue to do so? 

Asked by: Lucy
Thank you for your question. Mirtazapine requires a prescription from your veterinarian. Generally, Mirtazapine is given once a day to dogs, and twice a week to cats. However, dosages vary by weight and by veterinarians instructions so use accordingly. They will also tell you if your dog needs to be on it consistently or as needed regarding their situation.
Answered by: leanniejo
Date published: 2017-08-03

My vet prescribed a started dose usually used for a normal sized human 15 mg a day for my kitty with renal failure he said if if I don't think he's right find a different vet my cat is literally catatonic and dying no pun intended. Vets are hard to get

Asked by: Mb15759
Thank you for your question. What is your cat being treated for? Anorexia, behavioral disorder, or Inflammatory Bowel Disease? Mirtazapine is initially started at 15 mg for humans; however, there are few guidelines for dosing for animals since the medication comes from the human side. ASPACA Animal Poison Control Center did a study from 2006 - 2011 that monitored dosing for adverse effects. The study indicated that an appropriate starting dose for cats < 15 lbs = 1.875 mg (1/8 of a 15 mg tablet) is most common. Larger cats may have a dosage of 3.75 mg (1/4 of 15 mg tablet). Duration of treatment would depend on what your cat is being treated for. As for your cat having renal failure, a reduced dose of mirtazapine is needed due to impaired clearance of the drug.
Answered by: leanniejo
Date published: 2017-10-15

How long before you see mirtazapine take affect for a cats appetite

Asked by: Lady
Mirtazapine may take a few days to see the increased appetite affects. After two weeks contact your veterinarian if none are seen.
Answered by: Ben B
Date published: 2017-02-21

Just got the drug.  Has not been eating well due to heavy antibiotic schedule.  Can I start the pill tonight an hour before dinner 

Asked by: Rlslung
Yes this is fine to take one hour before dinner.
Answered by: Ben B
Date published: 2017-02-21

My dog takes 2 mg of selegiline every day for cognitive dysfunction but also has kidney disease with poor appetite.. is this safe to give him to increase appetite?

Asked by: LanaH
While Mirtazapine is a good option to stimulate your dogs appetite, it may interact with Selegiline. When given with Selegiline, Mirtazapine can increase the risk for additive serotonin related side effects. I recommend you speak with your veterinarian before giving both medications together.
Answered by: Christine
Date published: 2017-01-30
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