methimazole reactions and 2nd tries

laura mae

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My 15 year old cat Scooter has elevated t4 levels and was started on Methimazole last December. I didn't get to keep him on the medication to get to the full daily dose.  He became lethargic and anorexic just on the 1/4 tab two times a day dose. I had to stop the medication and syringe feed him for several days and it was alarming. It felt like it was a very close call.  I asked my vet about the compounded version that you put in the ear and she said  that if he didn't tolerate it in pill form he wouldn't tolerate the transdermal form. So he is not on the medication now. He continues to eat well and maintain his weight. He has good energy. He enjoys playing. He loves meal time. He doesn't look or act like a 15 year old.

I looked at a few short articles on the medication earlier and learned about felimazole which is coated to disguise the bitter flavor which might be part of the reason some cats become anorexic on it.  Are there more positive experiences with the felimazole? Has anyone tried the transdermal gel on cats that didn't react well to the methimazole? Was it tolerated? 

I also read that some life threatening reactions to methimazole is a drop in red blood cells and anemia. My girl Etta had so many things going on and hyperthyroid was one of them. She did ok on the methimazole but got an increase dosage and almost right away became anemic. The vet assumed it was her other conditions (fluid in the abdomen, nodules on the omentum--could have been cancer).  

I know that the best answer is to do the radioactive iodine treatment but my cat level expense with Charlie and Etta this summer exceeded $1800 for tests and treatments that ultimately didn't save their lives. Because Scooter could not get to the full dosage of the methimazole we have no idea the state of his kidneys without the hyperthyroid. The blood tests showed that his kidneys were in the lower end of the normal range--suggesting that without the hyperthyroid, he'd have some degree of kidney problems. So...we could do the radioactive iodine thing and he'll end up with 5 months in misery because of kidney decline because we just don't know how good they are.

Since Etta's passing, Scooter is super needy and having episodes of caterwauling which tells me that the thyroid issue has probably become more pronounced since December. Etta was his friend and he still looks for her 4 weeks after she's been gone so it could also be anxiety because his little world is very different than it was in May (both Charlie and Etta were alive then). 

I wonder if it is dangerous to try the felimazole given his swift and terrible reaction to the methimazole. Maybe with the coating it wouldn't upset his tummy and he wouldn't become anorexic. On the other hand I worry now about the anemia potential.

Thanks for any information you are willing to share.
 

mrsgreenjeens

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Just bumping this up for you.  Maybe you might start up another thread with a title something like "anyone use Felimazole?" since it seems like that's part of what you're asking.  Or I can ask a Mod to change the title of THIS thread if you'd like.
 

nurseangel

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I am sorry you and Scooter are having such a bad time of it right now.  My Garfield was treated on methimazole.  I wish I had the answers you are looking for.  We have had a lot of success with giving meds in liquid doses; my friend's husband works as a pharmacist in a compounding pharmacy and they add flavoring to the pet meds to disguise the taste.  I know I am not of much help, but wanted to offer you my support.   
 

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I'm so sorry you're dealing with this. I think you're asking good  questions that you won't be able to find the answers for here, or anywhere else online. They're very specific, and like you said, even a veterinarian would probably need to run more tests to give you any kind of questions. And as with everything in medicine and biology, it can be almost impossible to tell what the reaction of a specific individual will be. A good vet can try and evaluate but there are no guarantees. 

What I would do is try another vet for a second opinion. Preferably a feline expert. I know that's more expenses and yes, it may or may not give you the answers you need, but I can't think of any other way to get reliable answers. Or as reliable as they may get. I think this is one of those cases where answers from people on forums may end up confusing you more than helping. The same goes for Googling side effects, by the way. I've had a couple of personal experiences lately which made me understand why doctors don't like Dr. Google. We almost avoided medical treatment because we read about side effects and didn't understand why the doctor prescribed the drugs he did. I talked to doctor friends about it and turned out the doctor had in fact made the right decision - there were just considerations that we were not aware of (and neither was Dr. Google).
 

catwoman707

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My 15 year old cat Scooter has elevated t4 levels and was started on Methimazole last December. I didn't get to keep him on the medication to get to the full daily dose.  He became lethargic and anorexic just on the 1/4 tab two times a day dose. I had to stop the medication and syringe feed him for several days and it was alarming. It felt like it was a very close call.  I asked my vet about the compounded version that you put in the ear and she said  that if he didn't tolerate it in pill form he wouldn't tolerate the transdermal form. So he is not on the medication now. He continues to eat well and maintain his weight. He has good energy. He enjoys playing. He loves meal time. He doesn't look or act like a 15 year old.

I looked at a few short articles on the medication earlier and learned about felimazole which is coated to disguise the bitter flavor which might be part of the reason some cats become anorexic on it.  Are there more positive experiences with the felimazole? Has anyone tried the transdermal gel on cats that didn't react well to the methimazole? Was it tolerated? 

I also read that some life threatening reactions to methimazole is a drop in red blood cells and anemia. My girl Etta had so many things going on and hyperthyroid was one of them. She did ok on the methimazole but got an increase dosage and almost right away became anemic. The vet assumed it was her other conditions (fluid in the abdomen, nodules on the omentum--could have been cancer).  

I know that the best answer is to do the radioactive iodine treatment but my cat level expense with Charlie and Etta this summer exceeded $1800 for tests and treatments that ultimately didn't save their lives. Because Scooter could not get to the full dosage of the methimazole we have no idea the state of his kidneys without the hyperthyroid. The blood tests showed that his kidneys were in the lower end of the normal range--suggesting that without the hyperthyroid, he'd have some degree of kidney problems. So...we could do the radioactive iodine thing and he'll end up with 5 months in misery because of kidney decline because we just don't know how good they are.

Since Etta's passing, Scooter is super needy and having episodes of caterwauling which tells me that the thyroid issue has probably become more pronounced since December. Etta was his friend and he still looks for her 4 weeks after she's been gone so it could also be anxiety because his little world is very different than it was in May (both Charlie and Etta were alive then). 

I wonder if it is dangerous to try the felimazole given his swift and terrible reaction to the methimazole. Maybe with the coating it wouldn't upset his tummy and he wouldn't become anorexic. On the other hand I worry now about the anemia potential.

Thanks for any information you are willing to share.
I wish I had seen your thread sooner, and apologize, I'm sure you must be feeling very anxious.

The advice I give you is based on my experience, as I have 2 senior cats on methimazole now, one with CKD as well.

As for kidney loss, the fact is just about all cats will get this to some degree if they live to be old kitties, it's just the way this goes in cats.

So for Scooter to be showing loss on the lower end is not surprising at all.

Here's the very big concern for not treating his hyper-t at all. What you don't see is how hard his senior organs are now at work with uncontrolled hyper-t. Left untreated, this will shorten a cat's life, pretty substantially. It will end up causing organ failure, and often times heart disease or failure.

So leaving this untreated is not an option.

What strikes me in your post is, that the vet stated that transdermal gel won't be tolerated as the pills aren't. That's just not true, transdermal gel is considered to be much more tolerated.

He also should be started with a low dose, once a day, after a week twice a day, his levels checked after 3 weeks of starting.

A lower dose is often starting at 2.5 mgs/ml once daily.

My first girl Simone with CKD also, was started with 5 mgs/ml, and immediately was lethargic, constantly slept and stopped eating.

I dropped her dose in half on my own then told the vet I had, and she agreed.

She has since adapted perfectly and levels are right where they should be.

She is approx 16

Krissy, my 14 1/2 yr old with IBD has started on meth a week ago now, once daily at 2.5 dose, and you can't even tell she is on anything.

Both are on the transdermal gel.

There are more side effects with pills, so despite her analogy, you should request he be given a prescription for the gel at a low dose, then do a recheck.

I opted not to have the surgery done, it's too iffy and they are too old to be going through that, besides the cost even.

Hope this helps some.
 

basschick

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we use the methimazole transdermal - easy to give.

when your cat was lethargic, did your vet tell you to drop the dose?  that's what we had to do, and like catwoman707, after we cut the dose in half, the cat was fine.
 
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