Mirtazapine-Appetite stimulant, anybody?

[Cushpup]

Does anyone here have any experience with Mirtazapine (Remeron) as an appetite stimulant for dogs?

I know that Mirtazapine(It's an anti-depressant for people. It also stimulates appetite and has an anti-nausea component. People gain weight on it) and Cyproheptadine are given to dogs as appetite stimulants. Mirtazapine works better on dogs, while Cyproheptadine works better on cats.

The Vets around here know nothing about it. Dr. Allen from Dechra doesn't, either. I cannot find any information regarding DOG DOSE. There is a Vet who writes about it (Dr. Brooks) but she cannot give out a dose because she has to see the pet. That's not possible.

If anyone has any experience, or have found any articles with the dosage spelled out, I would appreciate your input. I may not need to give it to my dog, but I would like to know about dosage. Mine is 10 lbs.

TIA

M & M

[AlisonandMia]

Has your vet prescribed mirtazapine? Or is he/she looking into it?

I've managed to find a couple of online references that mention the canine dose:

http://commissionerspharmacy.com/pharmacy_content_html/s_vet/vet_misc.html and http://www.clarkpropharmacy.com/vet_misc.html (they both show the same text)


Mirtazapine for Appetite Stimulation in Dogs and Cats

Mirtazapine (Remeron™-Organon) is approved as an antidepressant for use in humans and has activity both as an alpha2 receptor antagonist and as a potent 5HT3 antagonist.A side effect noted in humans taking this drug is appetite stimulation. Pharmacy faculty at the Mississippi State College of Veterinary Medicine used mirtazapine in a dog after all other attempts at appetite stimulation had failed, and were very pleased to find that mirtazapine restored appetite almost immediately in this dog.In another case, a physician used mirtazapine to treat anorexia and nausea in his Boston Terrier with chronic renal failure. Due to the vast improvement in the animal’s quality of life for one month preceding its death, the dog’s primary care veterinary clinic conducted a series of uncontrolled field trials using mirtazapine over the next 4 years in 24 dogs and 17 cats with GI symptoms that were marginally responsive or refractory to standard remedies. “Mirtazapine therapy led to a robust response in 12 animals, improvement compared with standard treatment in 16 cases, and an equivocal response in 13 animals. The most vigorous responses were observed in patients in chronic renal failure or receiving concurrent chemotherapy for neoplastic disease.”

Many veterinarians have started using mirtazapine to stimulate appetite in both dogs and cats.There have been no controlled studies and dosing is still empirical, but most dogs are dosed at 0.6mg/kg orally every 24 hours and cats are dosed at 3.75mg/cat orally every 48-72 hours. The terminal half-life of mirtazapine in humans is more than 40 hours, and mirtazapine is eliminated partially through conjugation with glucuronide. For this reason, dosing intervals of less than 48 hours are not recommended for cats, as accumulation is likely. Mirtazapine is not commercially available in an oral suspension; however, compounding pharmacists have formulated suspensions upon the request of veterinarians and have anecdotally reported success with this dosage form. For cats that are vomiting as well as anorectic and cannot swallow or retain oral medications, veterinarians have instructed compounding pharmacists to formulate transdermal gels of mirtazapine (3.75mg/0.1ml), which also have left veterinarians with a positive impression of clinical efficacy. Obviously, further studies are needed to determine stability, safety and efficacy of these compounded dosage forms, but until such evidence is available, veterinarians may wish to try these dosage forms in cases that are refractory to traditional methods of appetite stimulation.



Note that info is from 2006 - new dosing info could be available now and the recommendations could have changed.

The people at Roadrunner may be able to help your vet with the dosing and even provide a liquid formulation for you to use.

One word of caution about this drug - from what I could see it is known to reduce the output of cortisol to a degree (was briefly looked at as a treatment for Cushing's). So giving it at the same time as trilostane could, theoretically, result in the cortisol level going too low. You should probably mention this to your vet before he/she goes ahead and prescribes it.

Alison

PS: To dig out this info I put the following into Google: Mirtazapine veterinary mg/kg

[tobybarnum]

I don't know how helpful this is, but my cat Barnum was saved by mirtazapine during a severe bout of pancreatitis. He was very ill, refusing to eat anything at all, and the vets were afraid he was on his way out. Just a couple of days of Mirtazapine, and he was out of the woods. Good luck!

[Cushpup]

Alison- Your'e the BEST! Thank you.

Thanks to everyone who chimes in with their experience with Mirtazapine.

I'm holding off on giving her an appetite stimulant. I found some articles on Mirtazapine and how 3 out of 4 dogs cortisol went down at first ( for 1 month). Then it didn't make much difference...so it appears to be 'inconclusive' whether Mirtazapine would lower the cortisol even more while using Trilostane...but THAT is my concern. I will run it by my Vet.

I've added DURALACTIN to her diet yesterday so we'll see if that will help her IBD, liver and her appetite. I'll let you guys know.

[gummysmurf]

I know this is late but I came across this post when I was googling mirtazapine for my dog, and thought I'd post in case it helps anyone else. We just got the prescription. Baxter is on chemo and he's basically stopped eating everything except McRibs, and even then he loses interest quickly. He won't even eat bacon. Can you imagine such a thing?!!

Baxter is approx 80 pounds and he's taking 1 tablet by mouth every 24 hours. When I googled it said exactly what the original poster said, that it's for serotonin increase in humans to treat depression, but that in veterinary use the side effects of decreased nausea and improved appetite are the reason it's prescribed. It can also cause constipation, which is good in Baxter's case because all the variety of food I've been trying to tempt him with has given him runny poops.

One other interesting thing - it also is rumoured to inhibit cortisol production in adrenal glands or some such thing - although apparently this use isn't recommended:

Mirtazapine decreases cortisol secretion by the adrenal glands but has not actually panned out as a treatment for Cushing's syndrome, where excess adrenal steroids are produced by the adrenal glands.