Mirtazapine for Dog Cancer
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Updated: October 10th, 2018
Dear Dog Lovers,
A newer drug is being used frequently lately, and I would like to make sure everyone dealing with a canine cancer diagnosis has heard of it. This medication may help some dogs out there, so let’s keep everyone up to date.
The drug is mirtazapine, also called Remeron.
Now granted, many of the readers of this blog want to know about diet and supplements. In the spirit of true integrated (full spectrum) medicine, we should look at everything conventional science has to offer, hence this post.
But for those who want to know what supplement I use in my patients, here is the quick answer: Apocaps. And yes, of course I am biased since I put it together and use it. It is not a nausea medication, rather it helps to normalize a critical process called apoptosis in the body.
Mirtazapine is a very effective appetite stimulant. This is particularly useful in cases of canine cancer, especially if either chemotherapy or the cancer itself is causing a loss of appetite.
On top of this, it helps with nausea and vomiting, and helps block spasm of the muscular wall of the stomach and intestine. This is useful as it not only improves nutrition by keeping food down, but on top of that, alleviation of vomiting is a major life quality positive.
But there’s more. Mirtazapine has a neat little antihistamine effect. Dogs with mast cell tumor cells in the body often have histamine excess, since the tumor cells secrete histamine. Too much histamine is not good for the body, causing swelling, redness, discomfort, nausea, vomiting, loss of appetite, and even low blood pressure. This makes mirtazapine very well suited for some dogs with mast cell tumors.
Finally, this medication is an antidepressant. Although there is little talk of canine depression’s link to cancer, there are some documented links in human medicine. In my opinion, the same reasoning may be applied to dogs, being sentient beings with happiness and sorrows like ours.
Mirtazapine was originally designed and intended for use in people for its antidepressant effect. However, in veterinary cancer care, we take advantage of mirtazapine’s effects on fighting nausea and helping with appetite. The effects on mood and anxiety are a bonus!
Mirtazapine works by increasing two chemicals in the body, serotonin and norepinephrine. A few other drugs also increase the levels of serotonin in the body. If these effects add up, a reaction can occur. Some other drugs that may significantly increase serotinin levels are Prozac (fluoxetine), Anipryl (selegeline), and Elavil (amitriptyline). You should double check with your veterinarian if your dog is on these drugs already, and you have a prescription for mirtazapine.
For more information on topics like this, check out The Dog Cancer Survival Guide.
Best,
Dr D
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.
Dr. Dressler,
Our 12 year old Bischon was just diagnosed with cancer. It is in her spleen, liver, and two lymph nodes. On top of that she has a gallstone and kidney stone. In January we were told that our dog was healthy after having blood work done! We had taken her in because she wasn’t eating good. Three weeks ago she just didn’t want to eat anything so I took her back in and told the vet I knew something was wrong with my dog!!! After radiographs and ultrasound we got the terrible news! Even with the option of surgery it is very doubtful our dog would survive for more than a month or two after putting her through it! The vet prescribed Mirtazapine to help her appetite. We started on Monday with 1- 15 mg pill. Yesterday she had diarrhea several times. Could this be the medicine or the cancer? We are trying to keep her eating and comfortable. Since the cancer has already spread we have decided not to put her through the surgery. This is the hardest thing to go through! She is a wonderful dog and we don’t want her to suffer! Any advise would be greatly appreciated!
Dr Dressler,
I have a similar question to the last post — given a pet with decreased/absent appetite, how long do the appetite stimulant & anti-nausea effects of mirtazapine typically begin take to ‘kick in’ after 1st dose?
Thanks for the info on this! We hope it’ll help.
Ben
Dear Ben
In my experience, if mirtazapine (Remeron) works it does so within four days or less, give or take.
Best,
Dr D
My 7 mo old lab was diagnosed with malignant histiocytic neoplasia four days ago. It presented as a massive tumor on her nose which seems to have impaired her senses of smell and taste. Between that and the chemo (4 days ago), she will eat absolutely nothing. Despite having taken mirtazapine for 3 days and prednisone for 4, she has shown no improvement in appetite. Should it be working by now, and if not, any suggestions on getting her to eat? I feel like I’ve tried everything – from chicken to cat food to pumpkin to maple syrup and more… Thanks.
This is in response to Rick’s comment above. I was told through my vet’s consultation with regard to Poly MVA that it shouldn’t be used on geriatric or debilitated dogs. Well, aren’t most dogs who get cancer old and debilitated? Or, the cancer makes them so? I ended up stopping it. What dogs were used in this determination that Poly MVA was supposed to be so wonderful? Why was I told not to use it on my dog with cancer who happened to be 14 but at the time I started it she did have cancer but really wasn’t debilitated. What were the characteristics of the 800 dogs and cats in this study? I hope my vet who did the consult did not misunderstand….
Lilly
Last June, my 9yo aussie developed perianal adenocarcinoma. She had surgery to remove it, went through 6 radiation sessions and was through 8/10 chemos, alternating Carboplatin and Doxorubicin. Through all of this she’s been taking Previcox and Pepcid-AC. She tolerated everything very well, but about 2 months ago she developed a big mass on the same side of the tumor. Two aspirations showed nothing. The mass got smaller and very, very hard next to her anus. Around the same time, she began to have a lot of trouble pooping. They did a biopsy thinking the tumor was back, but it came back as negative. An ultrasound of her abdomen and lungs was clear as well. Shortly afterwards, she got very ill, refusing to eat and throwing up. They found a “3 finger” hole in her large intestine. They fixed it, washed her insides and now she’s home. This was 2 weeks ago and she still has no appetite and turns her head at any offer of food, barely eating enough to stay alive. Would Mirtazapine help or is this something that will just take time??
Dr. Dressler,
My dog has undergone the WP, then a failed bone marrow transplant and is back on the WP. He just had his third week (Vincristine) and has virtually quit eating. He is a 105 lb. Chesapeake. Could you recommend a dosage of Remeron?
Fortunately my vet stated she is open to anything. I would love to get him many of the supplements in your book but his lack of appetite lately has ruled that out.
Thanks,
Davge
Dear Rick,
I have indeed researched it, but have not been able to access the data. Where is the actual data in this study?
Can you help?
Let us know as the readers and myself are interested!
Thank you very much
Dr Dressler
Hi Dr. Dressler
I was wondering if you have any knowledge/opinions about “procaspase-3 activator sulfonamide PAC-1”, which is being studied in a clinical trial at the University of Illinois. Here is a brief explanation:
Caspase-3 is a cell enzyme that directly leads to cell death. Cancer cells have higher levels of this enzyme compared to normal cells. Sulfonamide PAC-1 is a novel compound which leads to activation of this enzyme, thereby causing cell death in cancer cells and sparing normal cells.
I find this very intriguing because it sound much less toxic than chemotherapy drugs. I would appreciate any insights or opinions you may have.
Thanks,
Kay
Dear Kay,
I’m going to talk to Tim Fan next week about it and will try to keep everyone abreast of the information. Thanks!
Dr D
I used Mirtazapine during my Vizsla’s chemo when he stopped eating and it worked wonders! He actually put on weight during chemo and we could not have done it without the assistance of the Mirtazapine.
Darcy
Hi Doc,
I wrote before in regards to a cancer supplement called PolyMVA. I see where Dr. Ogilvie in San Diego has conducted cancer clinicals on over 800 dogs and cats with wonderful results using this non-toxic supplement.
I would appreciate your comments after reviewing the site and researching PolyMVA.
Thanks,
Rick