Felimazole

[vikinggirl34]

Today's Janie's 2nd day on Felimazole. I'd like to hear about anyone's experience with this medication.
here is her blood work:
Test Result Reference Range
FREE T4 >6.0 ng/dL H 0.7 - 2.6

 

[FeebysOwner]

Hi. The only thing I can tell you is that most vets prescribe Felimazole (methimazole) at too high of a dose to begin with. It is best to start low, test frequently, and adjust accordingly. Regardless of dosage, testing should be redone at 3 weeks, and again at 7 weeks, and again at 11 weeks before the dosage can be accurately assessed. The number you listed above seems to be for the T-4 test, not the free T-4 - there is a difference.

What dose have they started Janie on?

 

[vikinggirl34]

Hello Feeby--

Her free T4 below:

FREE T4 (pmol/L) >77.2 pmol/L reference range: 9.0 - 33.5

She started on 2.5 mg once daily. She has taken it two days in a row. I was thinking her appetite was a little down from it. I swear it seems like she slept more peacefully though....maybe just my imagination. I wonder if it slows their system down immediately from the high thyroid state. She is 16 years old and the hyperthyroid has already affected her heart -- bloodwork:
Test Result Reference Range
proBNP-Fel 357 pmol/L H 0 - 100
It looks like her kidneys and liver are hanging in there but not the best.

 

[vikinggirl34]

I wanted to take her for the I-131 radio iodine treatment but no one in my city has a facility that provides it....well, the one does but they temporarily suspended it for some reason...they didn't tell me why.

 

[FeebysOwner]

Thanks for the added information. 2.5 mg may not be a bad dosage at once a day, but generally it is advised to do 1.25 mg twice a day, to keep the meds balanced in the body. And, those follow ups checks are essential, IMO.

Feeby was diagnosed a year ago at 16+ yo, she had a T4 of 4.5 (range 0.8 - 4.0) and a free T-4 of >100 (range 0-50). We started her on 1.25mg twice a day, and have only raised it once to 1.875mg in the AM, and 1.25mg in the PM. Kidney issues can surface after Janie has been on the meds for a while - only time will tell about that. Feeby does have some kidney issues now. Janie's heart issues might be helped by the meds over time, however. Feeby was what they call apathetic hyperthyroidic - in that her only symptom was weight loss. So, I really wasn't able to decipher much of a change in her relative to taking the meds. She has done well on the meds overall, but issues have cropped up lately that look more to be related to the unmasked kidney disease.

Janie has to be on the H-T meds for a while before being tested for eligibility to undergo I-131 treatment anyway, so keep following up with the facility who offers it.

In the meantime, please check out this web site for a whole host of information - Animal Endocrine Clinic | Where science and compassion cure. Wonderful information about hyperthyroidism in general and a lot of data pertaining to the I-131 treatment as well.

Janie is very pretty! And, please come back with all the questions you have now or may have in the future.

 

[neely]

Carleton is on Methimazole for Hyperthyroidism - 1.25 twice a day spaced 12 hours apart. (Our vet emphasized the 12 hour spacing between doses.) He has done considerably well in that his T-4/Free T-4 has gone down. Two of his feline specialty vets felt he is a good candidate for the I-131 treatment. He is 11 yrs. old, soon to be 12 yrs. old, but since we adopted him we are uncertain of his exact age. Last week he had preliminary tests and x-rays done before getting the I-131 at the end of this month. The vet was concerned about a spot that showed up on his x-rays near his heart and is waiting for the radiologist's input. Since you mentioned Janie's H-T has already affected her heart this might be an issue for her getting the I-131 but that is entirely up to your vet and the diagnostic/imaging team that would handle the radioactive iodine treatment.

I completely understand how frustrating this can be for you since you want to help Janie as much as possible. Going back to your original question about Methimazole - I have been using the Transdermal Gel form of it and it's worked out well for us. I hope it helps Janie too. Please keep us updated on her progress.

 

[vikinggirl34]

Thanks for all the replies! I think I will dose 2x a day @ 1.25 mg....makes sense that way to me...keep the meds steady in her system.

Also, has anyone tried Hill's Prescription Thyroid Care also along with the meds? I have an order of dry and wet thyroid care being delivered today from Chewy.

 

[FeebysOwner]

Also, has anyone tried Hill's Prescription Thyroid Care also along with the meds? I have an order of dry and wet thyroid care being delivered today from Chewy

I am not sure that if you are using Felimazole you should also be feeding Janie the thyroid care food. I believe it is 'one or the other' in terms of treatment, given that the food has a reduced level of iodine and the meds are used to block the production of thyroid hormones which involve iodine.

Thyroid care foods are generally lower in protein, which isn't necessarily a good thing for older cats who tend to lose muscle mass as they age. It is common for cats to either dislike the thyroid food or grow tired of it very quickly too.

Ask your vet if you should be using both at the same time.

 

[vikinggirl34]

I have a call into the vet. I just assumed it was ok being they had to write the authorization for the food. Best to double-check.

 

[fionasmom]

Fiona herself was on Felimazole for several years and did fine with it. I was not informed at the time of the possibility of another treatment, so did not pursue that option. Fiona was difficult to pill, so it was crushed into BFF food every day. Despite the fact that it is not the optimum way to administer this, she still was fine.

We never got even close to her eating the food, so that avenue was closed to us. I agree that it is one or the other with the food. Other pets are not supposed to eat it, and the cat with hyperthyroidism is supposed to eat only that, so it can get tricky to manage.

 

[vikinggirl34]

Fionasmom,

Luckily Janie is the only cat in the house. I'm considering food only after 3 days now of the Felimazole...it seems like her appetite tanked. She used to have a good appetite. Now I'm pulling teeth to get her to eat. Hopefully, she will take to the thyroid care food. I still haven't heard back from the vet but will go with only one form of treatment..... food or pills...not both.

 

[vikinggirl34]

Food delivery today from Chewy: She loves the food.....yay! **Fingers crossed**

 

[FeebysOwner]

Food delivery today from Chewy: She loves the food.....yay! **Fingers crossed**

That's good! So, the vet said it is OK to use Felimazole and the thyroid food at the same time? Wow.

 

[vikinggirl34]

I still have yet to hear back from the vet. I called yesterday. After 3 days of the Felimazole, I stopped because her appetite was just about almost gone. So I'm going with the food only until I hear otherwise. I'm worried about medicating with something that is going to kill her appetite.

 

[FeebysOwner]

I still have yet to hear back from the vet. I called yesterday. After 3 days of the Felimazole, I stopped because her appetite was just about almost gone. So I'm going with the food only until I hear otherwise. I'm worried about medicating with something that is going to kill her appetite.

Feeby never had a change in appetite one way or the other, but she also did not demonstrate excess hunger/eating with her H-T to begin with, just weight loss.

There are cats who don't do well with the medication, and there are some that need some sort of gastric related meds to help out. When you do talk to the vet, ask about the transdermal version, as it tends to avoid gastric related issues. However, you might be able to keep her on the thyroid food exclusively for now, and worry about what to do later if she chooses not to eat it. The biggest problem with the food is that most cats don't like it, or they end up not wanting to eat it after a while.

I think it is a very good idea you stopped the Felimazole, and just feed her the thyroid food for now. I really don't think it is advisable to do both at the same time. Good for Janie that she likes the food!!

 

[FeebysOwner]

I also want to ask about where the blood work was done. The numbers are a bit unusual for normal testing results, and may be related to 'in house' testing as opposed to outside lab testing which is typically much more precise. The greater than (>) on a T-4 is not typical, and normally can be better narrowed down than that.

If you can share the actual report on the overall results (of course, block out names as you can), that would be good too.

I, and others on this site, have been where you are at, and while we may not have all the answers, we can provide guidance, and we do care because we 'know and understand'.

 

[vikinggirl34]

Janie's signs of HT were increased water intake/output and weight loss. I had taken her to the vet before COVID hit and at that time the bloodwork showed normal. Her food intake was about average. As I mentioned, the Felimazole seemed to kill her appetite. I did attach the full bloodwork report (names have been removed to protect the innocent)

 

[FeebysOwner]

Thanks! That is a very hard report to read!! I did see further down in the report where the T4 was listed as 8.8 ug/dL (range 0.8 - 4.7); that is more like what I normally see in terms of a standard range.

Does the vet think Janie's heart issues might be related to the H-T? Heart conditions can be brought on by H-T, and most are reversible with H-T treatment. I hope that is Janie's case. Will they be doing follow up tests after Janie has been on the thyroid food for a while? I know they wanted Feeby's first follow up tests done once she had been on Felimazole for 3 weeks - not sure how that works with the thyroid food as Janie's main treatment.

I hope Janie continues to like the thyroid food, and that her next thyroid test shows positive results. Keep us posted!!!

 

[vikinggirl34]

I had to call the vet office back as I have not heard from them (called last Thursday) -- a vet tech said "yes" it's ok to use Felimazole and HIll's Prescription Thyroid Care in conjunction with each other.

 

[FeebysOwner]

I had to call the vet office back as I have not heard from them (called last Thursday) -- a vet tech said "yes" it's ok to use Felimazole and HIll's Prescription Thyroid Care in conjunction with each other.

I would not do it. It will make it much harder to accurately evaluate his thyroid numbers when he is re-tested. If/when I can find the data in the link I provided to you earlier where it says 'either-or' I will share it here.

You could also join this forum (for free) and get the opinions of others whose cats are hyperthyroidic. [email protected] | Home.