Felimazole side effects

[fionasmom]

Fiona, who is almost 15, has recently been placed on Felimazole for hyperthroid treatment. Her readings were very high; some kidney issues, recent dental cleaning and extraction of 2 troublesome teeth which seemed to give her a new lease on life.  The dose is the standard 2.5 mg 2 times a day, administed first with a pill popper, now placed in the food.  She does not like to be handled, so the ear gel may not be a reliable way to administer it.  So far, BFF packets have ensured that she takes the whole pill, even if it has to be crushed in the pill crusher.

She has been on the drug since 12/26/14.  After about a week, I noticed serious lethargy, lack of appetite, and vomiting. I cut the pill back to one per day, with the vet's agreement, and the appetite returned, along with some energy and decreased vomiting.

A few days ago I noticed a moist spot on her face under the eye...throught that the eye was runny, but it was fine. About one day later it was wetter and next day it was opening and red, with some blood.  Given the life she leads, there is practically no chance that she encountered anything which injured her.  

I have been reading the pamphlet which came with the Felimazole since this whole thyroid issue came up and am concerned that she is having what they call "skin lesions" or "facial excoriations". When I googled it and found a very informative article from a vet endocrine specialist, I was upset to see how far the skin condition can advance.

My question is really only this....has anyone had this side effect to this medication?  At her advanced age, I am not going to turn her into a medical experiment or do anything that would cause her to suffer as I have tried to avoid that her whole life.  If her face falling to pieces is part of the regime, I will probably just take her off the med and make her comfortable for as long as I can.

 Thanks so much.

 

[mrsgreenjeens]

Just bumping this thread up in case someone missed it.  I, personally, don't recall hearing anyone discuss this as a side effect.

 

[fionasmom]

Thanks for moving the thread up just in case anyone has had this happen. This side effect is clearly discussed in the literature about the medication, but it seemed to me at first to be one of those things which is never going to happen to "your cat."  I have known people who have used Felimazole and methimazole and have not experienced this.

 

[castle cat]

A week ago I read your thread about your cat. Before I touch the subject of Felimazole tablets, let me write briefly about my 18 year old, long haired Norwegian Forest cat, Jethro. In September 2012 he was diagnosed with CKD. The vet prescribed FORTEKOR (tablets) 5 mg. I should give him one tablet a day. Also he should eat veterinary diet Renal (canned, dry and in pouches) and nothing else.

Jethro has been taking FORTEKOR tablet (every evening) since September 2012. Twice a year the vet carried out blood tests and the results were not alarming. Before he was diagnosed with kidney failure he weighed 5 kg. In September 2014 he weighed 4 kg and in January 2015 he weighed 3.50. He became very thin and his mobility has been restricted by the muscle loss. I was very much worried. When his blood was tested in the last week of January the results were not encouraging. But I was not convinced because the vet disagreed to my explanation that dehydration can give incorrect results. Jethro has been eating well. (Integra kidney food and Royal Canin’s Senior Consult Stage 1 – he dined on sauce only and refused to eat the small pieces!) The vet suggested that it’s better to put him to sleep.

The next week (on Friday, February 6, 2015 I took him to another vet in the neighbouring town to get a second opinion. His assistant (also a vet) attended Jethro, read the results and suggested that I should wait a month for a new blood test. She said that Jethro in addition to kidney failure he is also suffering from hyperthyroidism. Then she consulted her colleague who’s on a course, by phone. She read out the results, discussed with him for about 5 minutes. Both felt that FELIMAZOLE is the answer for hyperthyroidism. She warned me that the tablets might worsen condition of his kidneys! She gave three cans of Hill’s y/d and a bag of y/d dry food. On my return I spent the weekend surfing internet.

I read the following.

http://www.drugs.com/pro/felimazole.html

http://www.catinfo.org/?link=felinehyperthyroidism

http://www.animalendocrine.com/

http://animalendocrine.blogspot.no/2011/09/confirming-diagnosis-of-hyperthyroidism_10.html

http://animalendocrine.blogspot.no/2011/10/treating-cats-with-hyperthyroidism.html

http://endocrinevet.blogspot.no/2011/09/best-diet-to-feed-hyperthyroid-cats.html

http://endocrinevet.blogspot.no/2011/09/is-hills-yd-nutritious-diet-for.html

http://endocrinevet.blogspot.no/2011/11/is-protein-content-of-hills-yd-too-low.html

http://animalendocrine.blogspot.no/2012/05/can-new-thyroid-health-food-hills-yd.html

http://catexpert.blogspot.no/2013/05/hills-yd-for-feline-hyperthyroidism.html

I was scared about side effects of the tablets. On Monday evening I called the vet (who has returned from the course) and asked for side effects of Felimazole. He promised to call me back in an hour or two. Not satisfied with his promise I mailed him the above links. Exactly an hour later he called and asked me NOT to administer FELIMAZOLE tablets. As Jethro is eating well in spite of weight loss, there’s no necessity of trying the new medicine. FORTEKOR is sufficient. But he reminded me that Jethro is old and I should accept his weakening condition.

In about ten days I’ll be taking him to the vet for blood test. I still believe the results of January blood tests are incorrect. Let me see how the results will be in the forthcoming test. I will post the results.

This reply is coming from Norway!

Best wishes,

Castle Cat

 

[fionasmom]

Thank you so much for this reply and I have to apologize for not finding it sooner. My dog was just dxed with Cushings...third cushpup...and I became involved in trying to do the right thing for him.  Your reply is astounding and I am going to pass the info onto a friend in PA as well.  My cat Fiona is still with me, the facial sores seems to have healed when I put Zymox on them, but she is very thin and evidently her kidney condition has worsened....I can tell this from the quantity of water and pee.  She is very happy however, goes outside with me daily and we sit in the sun, sleeps with me at night, and still has enough energy to run across the yard after lizards.  Her appetite is good; however, I think that I also have to accept that at 15 she is not going to make it another 15 years.

I have to wonder about the Felimazole. Mary, my friend in PA, noticed a big improvement in her cat when she took it upon herself to cut the dose of the Felimazole.  I am going to read all your links and appreciate your kindess in taking time with this question for me.

 

[castle cat]

Hello

fionasmom,

Sorry for not replying immediately. How's Fiona doing? I hope she's in good health. I wish both of you good health and happiness.

On Monday, April 13, my darling Jethro has departed from this world. My eyes filled with tears as I'm replying you. I still cannot believe that he has left. I have written on this site about Jethro titled, 'Jethro's Final Journey.' I have uploaded some photographs. Please take a look at them.

Castle Cat 

 

[a17pril]

Hi, just been looking for info about Felimazole and found your post. Freddie has been on F for a few weeks and recently had the dose doubled. We thought he had been fighting as he had several scratches on his face but it appears that he is suffering from facial lesions which are actually spreading down his neck and onto his back
Vet has given him antibiotics and taken him off F immediately. Was told this was a very rare side effect.

 

[ACatMan]

Hi, found this thread doing a bit of research. And since it's been a while since the last, thought to contribute with content that might be useful to others.

About 1 month ago from date our male cat (soon 14) was diagnosed with Feline Hyperthyroidism. The symptoms had built up over time. We are still not sure what instigated or propelled it. Might have been genetic, might have been (partially) catlyzed by diet?

Anyways....

From before our cat has been hyper allergic all hsi life. Pure luck and timing made it possible, with a at the time new vetrinary allergy test, to determine at least some of the proteins he did not tolerate. That taught us a lot about cat dermatology, and what most mainstream cat food is made of, why it is (generally) not good.

Different topic, fast forward.. A blood sample substantiated his diagnose and Felimazole pills, 2.5.mg twice daily was prescribed. According to the vet, this is the norm when starting a treatment.

The first days we did not observe anything special. Then after a few days we noticed a psychological change, usually an hour or two after each pill. Lethargy. loss of appetite, purring vanished, but also... heart rate went down.

We struggled with administering the pills, the cat hated them. Did a bit of research and discovered a liquid called Apelka Vet, 5mg/ml thiamazole. It actually had arrived in our country just a few days before so guess we were among the very first to try it out.

It could have been a connection between diet (we've given him a quite a lot of fish due to metabolism/hunger) and the medicine, but not long after, lesions or lumps started to break out, violently. With a hyper allergic cat we've seen this on/off since he was a kitten, sometimes his reactions could come after 15-20 minutes. Those reactions however, were infused or driven by proteins, and unpure or highly mixed cat food.

Our cat has been on (mainly) Royal Canin Hypoallergenic food for his entire life. Without this food, which is the purest/best there is (a new type is also out now called Royal Canin Anallergenic) his life would be rather miserable.

Back to the topic....

The outbreak was substantial so the first thing we did was to eliminate high iodine intake (sadly meant no more [saltwater] cooked fish). Then we contacted the vet and brought him in for another blood sample. This revealed values had dropped into the very lowest end of the spectrum.

A decision was made to reduce the dose to half, twice daily. He's been on this now for approx 4-5 days. The cat's been out and scratched himself quite a bit which have made things worse. A couple of days ago we therefore decided to detain him and put a collar (or lampshade) on. He will be kept indoors for some days while we monitor changes (hopefully progress).

We believe we see a change, lumps are drying up, he's not so focused on the areas anymore. We've started to wash the area twice a day with purified water. Reason for this is that he seems to like it, the washing helps the drying up process and he's less inclined to want to wash/mess things up.

This is about as far as we've come. Future will tell where things go from here. Hopefully this info will be useful to others in the same situation.