Hyperthyroid - when will meds take effect?

[5DH]

My cat (13) has lost a bit of weight with increased appetite so the vet started him on 1.25mg methimazole once per day. She originally wanted to do twice a day but I kind of talked her into once/day since his thyroid level was “normal” but on the high end (4.5).

He is approaching 3 weeks on the meds and the doctor wants to redo bloodwork. But should I have noticed a change in symptoms? I understand weight gain will take more time but he still has an elevated appetite.

I asked the vet if I should just move it to twice/day as originally recommended and they just said I should do the bloodwork and go from there.

It’s $230 every time I do the blood test so I’m just trying to avoid unnecessary blood tests, this vet is very conservative and always recommends all the tests possible. Not to mention I have to dose him with gabapentin before the blood test which I don’t love doing.

Wondering from experiences here: how long until you noticed your cat’s appetite return to normal? Any other words of wisdom from people with hyperthyroid kitties?

 

[Mac and Cats]

I think twice per day is usually the recommended as it can keep their levels a bit more stable by taking it every 12 hours vs. taking it once every 24 hours. It sounds like maybe twice per day might be better for your cat. I would probably be inclined to test his levels again before making that call again.

I have two cats with hyperthyroid and both take Methimazole. The younger of the two (14) takes 2.5mg twice per day. She was on the higher side of normal as well and we caught it very, very early. At first we did 2.5 once per day and 1.25 once per day (12 hours a part), but when we re-tested after 3 weeks, our vet thought it would be best to bump her up to 2.5 twice per day. I didn't notice that much of a difference with her, but we caught it so early that she did not even lose any weight or really change her eating habits.

Our other cat was a completely different story. He was 7.5 pounds when we brought him home from the shelter and he was diagnosed that day with hyperthyroid. Someone had found him outside in a box and turned him into the shelter. He was 13 (this is going based off his microchip information). So, who knows how long he had been living with it untreated. Long enough to get down to 7.5 pounds, when he should probably be around 13. Anyway, long story short, he was put on 5mg twice a day by the shelter vet and his levels were pretty high. After a few weeks, we brought him to our regular vet, retested his T4 and she cut the dose in half to 2.5mg twice a day. He was on 2.5mg twice a day for almost two years, I think. I would say with him, it took maybe 3-4 weeks to notice a difference in his behavior/eating? Meaning, he was pretty hyper and active and eating like he was starving for a few weeks. I feel like maybe it took about a month for him to stop acting totally ravenous, but I could be misremembering. He still ate a lot and gained back some weight within a couple months. I'd say he leveled out after a couple months and as the months moved along, he started getting pickier with food, but that's a completely different story and another health issue. Anyway, now he's on 2.5mg in the morning and 5mg in the evening, hovers around 11-12 pounds and he just acts like a normal 15 year old cat with a pretty normal appetite.

Not sure if that info is helpful to you, but that is our experience.

 

[FeebysOwner]

My cat started out with a 4.5 reading for her thyroid level, and she was placed on - with my 'encouragement' to keep the dose on the low side to begin with - 1.25mg twice a day. Her only symptom was weight loss, which did subside relatively quickly - not that she gained the weight back, but that she stopped losing weight.

The twice a day dosing is often preferred just to help keep a steadier stream of meds in the cat's system. There have been occasions whereby the med is cut into smaller portions to get a proper dosing amount. I actually have to do that now with my cat.

However, having said all that, I would never change the dosage by myself without a thyroid check. And tbh, 3-4 weeks after initially starting thyroid meds is pretty much the standard for a re-check. If another dosage change is required at that time, another re-check is appropriate in 3-4 more weeks. Additional checks can be done less frequently once the thyroid level has been stabilized.

You can ask your vet what the cost would be to just check the thyroid level, without the additional blood work, and see what they say.

 

[IndyJones]

For Kabuto I noticed the medicine started to have an effect within a week he was put on 1.25mg twice a day and still is on this dose. The vet took a sample three weeks after and found his thyroid back where it was supposed to be and no masked CRF.

 

[Mac and Cats]

I don't know why I can't edit my post, but I would like to add that the retest 1-3 times after the initial diagnosis is normal and it generally is every 3-4 weeks. This is to make sure you're on the right track and the right dosage of medication. If it seems their levels are evening out or they are doing ok on whatever dose they are on, your re-checks will probably be limited. I would also never change the dose or amounts daily without doing this test and the guidance of your vet.

 

[FeebysOwner]

I don't know why I can't edit my post,

Off topic, but to respond to your issue, there is usually a 120 minute time line for editing posts. If you fall out of that window, no further editing can be done. I think the time restriction is to reduce confusion that could transpire with altering posts beyond a reasonable period of time when many have already seen them. Nonetheless, as long as you see the "Edit" option on the lower left hand side of your post, you should be able to alter it.

 

[emocatowner]

My cat (13) has lost a bit of weight with increased appetite so the vet started him on 1.25mg methimazole once per day. She originally wanted to do twice a day but I kind of talked her into once/day since his thyroid level was “normal” but on the high end (4.5).

He is approaching 3 weeks on the meds and the doctor wants to redo bloodwork. But should I have noticed a change in symptoms? I understand weight gain will take more time but he still has an elevated appetite.

I asked the vet if I should just move it to twice/day as originally recommended and they just said I should do the bloodwork and go from there.

It’s $230 every time I do the blood test so I’m just trying to avoid unnecessary blood tests, this vet is very conservative and always recommends all the tests possible. Not to mention I have to dose him with gabapentin before the blood test which I don’t love doing.

Wondering from experiences here: how long until you noticed your cat’s appetite return to normal? Any other words of wisdom from people with hyperthyroid kitties?

Seconding what everyone else is saying. After 3 weeks is the norm, so they can up the meds if it isn't working well enough, though once it's stable, you'll be able to switch to every 3-6 months. 1.25 once a day is a very very low dose, so it may not do enough, though many start this low, particularly in older cats, to ensure no kidney surprises. Though it is kinda weird they're starting treatment after one test where it's high, usually you wait and repeat the test in 3 weeks to confirm, and only then start meds.

You can also look into radioactive iodine therapy, it's crazy expensive, but it can be cheaper than the cost of meds after 2 years. Surgery is also a much cheaper option, but also more risky.

And ideally you do want meds to be twice a day, it's not going to be in the system that long. But there are ways to make giving meds more pleasant, my old dude hated pills at first, but I always gave him a snack afterwards, so after a while, he'd start meowing at me a few minutes before it was time for his meds. And there is a liquid version that I switched him to, which must taste pretty good, since he was so happy to have it every time.

You can also check what kind of blood test they're doing, and if there is one that can only do T4. My old vet would have to send it to a lab and they'd do a full panel, it was like $350 and they'd have to take several vials off the poor kitty. My new vet has in-house equipment, it's like $60 for this specific test, $50 for a kidney panel, plus a $40 blood draw fee, it's just a couple tiny vials and we get results instantly, and the blood draw fee is justified as they used a ton of Feliway, had a nurse helping with restraint etc, old vet was on her own and had to use a sedative. So you may be able to find one that can do this specific test in-house for cheap too (ask at the more expensive clinics too, my new vet is literally the most pricey in town if you look at their website, but they've saved me a ton of money compared to my old "cheap" vet)

As for timeline, it's common for cats to be very nauseous a week or two after starting treatment (often involving lots of vomiting). So appetite may well be worse for a while.

My dude got one test where it was 5.6, and he was already a bit under the weather due to kidney disease so we wouldn't even have known without the test. Except maybe that he was more playful than he'd been in the whole time we had him for a while! Then we repeated the test, it was up to 6.5, so we started medicating. It went down to 4.2 at the 3 week checkup. 2 months later it went down to 3, and it kept being around 3 for the rest of his life.

 

[Mac and Cats]

You can also look into radioactive iodine therapy, it's crazy expensive, but it can be cheaper than the cost of meds after 2 years.

I've seen this said many times by many people and it makes me wonder what crazy prices you guys are paying for meds?! I know the compounded meds are much more expensive. So, maybe I'm just lucky I don't have to go that route? I think a 40 day supply for one of my cats is $12.99 at Costco? My other cat that is on Felimazole and it is only a few bucks more. I'm just too lazy to it get changed to the regular non-coated kind. When I looked into the radiation treatment here in the PNW last year, it was around $3,500. I was considering doing it, but then our other cat got diagnosed as well and I thought, well how do I pick which one gets it and which one doesn't? Plus, we can't really afford it anyway.

Also, my understanding is the "in house" quick T4 results aren't super detailed and that the ones you have to send out to a lab give you more specific numbers? But maybe someone else can chime in on that?

 

[emocatowner]

I've seen this said many times by many people and it makes me wonder what crazy prices you guys are paying for meds?! I know the compounded meds are much more expensive. So, maybe I'm just lucky I don't have to go that route? I think a 40 day supply for one of my cats is $12.99 at Costco? My other cat that is on Felimazole and it is only a few bucks more. I'm just too lazy to it get changed to the regular non-coated kind. When I looked into the radiation treatment here in the PNW last year, it was around $3,500. I was considering doing it, but then our other cat got diagnosed as well and I thought, well how do I pick which one gets it and which one doesn't? Plus, we can't really afford it anyway.

Honestly, I read it in a book written by a UK vet that I read just after my cat got diagnosed.
It's not cheaper where I live either, but it's a good idea to check prices, because it is somewhere.

In terms of whether it's worth doing, I read some studies on how cats live on average for 2 years on meds and 3 years with radioactive iodine. So I was tempted to get it done, but my dude wasn't a great candidate due to his kidney issues. On the other hand, one of the most common questions I see online about this is "I want to go on a weekend trip, will my cat be ok for 2 days without meds?". Also my dude was a notorious pill spitter, hiding the pill in his cheeks so he'd swallow, then I'd watch him like a hawk for 5 mins, and then find the tiny pill on the floor somewhere, not sure which dose it's even from - one reason why I switched him to liquid. So I'm guessing that many of the cats in the study didn't have perfect pilling of those cats, which is what shortened their lifespans.

 

[Mac and Cats]

Honestly, I read it in a book written by a UK vet that I read just after my cat got diagnosed.
It's not cheaper where I live either, but it's a good idea to check prices, because it is somewhere.

In terms of whether it's worth doing, I read some studies on how cats live on average for 2 years on meds and 3 years with radioactive iodine. So I was tempted to get it done, but my dude wasn't a great candidate due to his kidney issues. On the other hand, one of the most common questions I see online about this is "I want to go on a weekend trip, will my cat be ok for 2 days without meds?". Also my dude was a notorious pill spitter, hiding the pill in his cheeks so he'd swallow, then I'd watch him like a hawk for 5 mins, and then find the tiny pill on the floor somewhere, not sure which dose it's even from - one reason why I switched him to liquid. So I'm guessing that many of the cats in the study didn't have perfect pilling of those cats, which is what shortened their lifespans.

That makes sense. I am a complete introvert so I love ANY excuse to not be able to commit to something social! Terrible, I know. It does make it difficult if you're a person who likes to have a life. I would for sure NOT be ok with not pilling them for two days. I can only sort of get on board with giving them the meds late if I absolutely have no other choice. If I were rich, I would absolutely do the radiation treatment for both cats and if they were both candidates. Unfortunately, with prices the way they are now, I sometimes wonder how we are even feeding our animals!

Edit: Also, here is a source that says cats can live around 5 or more years after diagnosis when treated properly for hyperthyroid. I don't know how reputable this source is, but it's there.

 

[fionasmom]

I don't think that the article is incorrect, but probably comes down to experience with individual cats. Fiona herself lived for three years on Felimazole. At the time, I was unfamiliar with the radioactive iodine procedure but would have considered it.

My experience was that Felimazole was not very expensive; thyroid medications for hyper and hypo tend not to be and the procedure is much more expensive.

If emocatowner new vet has invested in laboratory quality equipment, it makes sense to me that they are able to offer these tests for less.

 

[neely]

When I looked into the radiation treatment here in the PNW last year, it was around $3,500. Also, my understanding is the "in house" quick T4 results aren't super detailed and that the ones you have to send out to a lab give you more specific numbers? But maybe someone else can chime in on that?

When our cat was diagnosed with H-T approx. two years ago we started him on Methimazole but since he was a good candidate for the I-131 radioactive iodine treatment we decided to do it. It was nowhere near $3,500 and the facility we chose was a veterinary medical specialty hospital affiliated with one of the top universities which does Scintigraphy prior to receiving the injection. In order to ensure the best outcome for your cat Scintigraphy is compulsory. I'm sure location may affect the cost of the I-131 procedure.

Yes, a T-4 test is normally sent out to a lab. Feline Thyroid Tests

 

[Antonio65]

It’s $230 every time I do the blood test so I’m just trying to avoid unnecessary blood tests, this vet is very conservative and always recommends all the tests possible. Not to mention I have to dose him with gabapentin before the blood test which I don’t love doing.

Keep in mind that testing periodically your cat during the methimazole treatment is part of the therapy, and it is needed to make sure that the current dosage is till effective or working.

My cat was on 1.25 mg twice a day (pill) before we decided to switch to eargel, which was much easier to administer.
Anyway, we kept testing the cat every 5 to 6 weeks to make sure that we didn't need any adjustment. And it turned out to be the right decision, because during the 10 months long therapy, we changed the dosage at least three times, even down to 0.625 mg twice a day.

Eventually the cat was admitted for the I-131 therapy and we stopped giving her the med.

 

[5DH]

Keep in mind that testing periodically your cat during the methimazole treatment is part of the therapy, and it is needed to make sure that the current dosage is till effective or working.

Understand. And, since he's so borderline the good news is it's not a crisis situation. The vet said his weight had gone from overweight to normal so he's not in any weight danger, got it nice and early. But my understanding from the vet is that the periodic testing will be like every 4-6 months. If it's every 3 weeks, it doesn't make any sense to continue with this treatment as opposed to just doing the higher up-front cost of the I-131... it'll pay for itself!

What was the process like for the I-131 for your kitty? By all accounts it seems like there are few side effects, just have to deal with the days in isolation.

 

[5DH]

I've seen this said many times by many people and it makes me wonder what crazy prices you guys are paying for meds?! I know the compounded meds are much more expensive. So, maybe I'm just lucky I don't have to go that route? I think a 40 day supply for one of my cats is $12.99 at Costco? My other cat that is on Felimazole and it is only a few bucks more. I'm just too lazy to it get changed to the regular non-coated kind. When I looked into the radiation treatment here in the PNW last year, it was around $3,500. I was considering doing it, but then our other cat got diagnosed as well and I thought, well how do I pick which one gets it and which one doesn't? Plus, we can't really afford it anyway.

For me it would come down to the timeline. I think the whole "cats live 2 years on the pill or 3 years after I-131" is a bit misleading, simply because cats are typically already in their teens when they get diagnosed, so someone would need to connect the thyroid issue to the cause of death for me to believe one treatment is better than the other.

The meds are really cheap for me too. It's the bloodwork that's expensive. 10 blood tests is the price of just doing the I-131 treatment (plus the convenience of no longer giving a twice daily pill, not worrying about it getting worse over time, and for my guy having to give him gabapentin just to do the blood draw which turns him into a zombie for a half day).

 

[Mac and Cats]

For me it would come down to the timeline. I think the whole "cats live 2 years on the pill or 3 years after I-131" is a bit misleading, simply because cats are typically already in their teens when they get diagnosed, so someone would need to connect the thyroid issue to the cause of death for me to believe one treatment is better than the other.

The meds are really cheap for me too. It's the bloodwork that's expensive. 10 blood tests is the price of just doing the I-131 treatment (plus the convenience of no longer giving a twice daily pill, not worrying about it getting worse over time, and for my guy having to give him gabapentin just to do the blood draw which turns him into a zombie for a half day).

That's a good point! I was not taking the blood tests into account. We have our two oldest cats on a wellness plan that is paid for monthly and it includes a couple blood tests yearly. That's probably why I wasn't thinking of that since I'm only seeing the actual costs of that if they need extra ones throughout the year. We are paying for them, obviously, it just don't usually come at me all in a big cost.

 

[FeebysOwner]

so someone would need to connect the thyroid issue to the cause of death for me to believe one treatment is better than the other...The meds are really cheap for me too. It's the bloodwork that's expensive. 10 blood tests is the price of just doing the I-131 treatment (plus the convenience of no longer giving a twice daily pill, not worrying about it getting worse over time, and for my guy having to give him gabapentin just to do the blood draw which turns him into a zombie for a half day).

The two treatments are not equal, regardless of any averages being discussed on life expectancy - the meds still allow the thyroid tumor to grow, and as it grows the meds need to be increased. Radio iodine treatment is a cure.

I still say that unless your vet is telling you that blood work needs to be done every 3-4 weeks for the rest of your cat's life, which is a bit extreme, once the thyroid level has been stabilized it is very common to extend the re-testing to every 6 months. The only reason at that point to do it more often would be if you saw signs to suggest the meds are not working as effectively as they had been.

 

[fionasmom]

Range for the treatment around here seems to be from $1200 to $3000. Area seems to be most of California.

 

[Antonio65]

I've seen this said many times by many people and it makes me wonder what crazy prices you guys are paying for meds?! I know the compounded meds are much more expensive. So, maybe I'm just lucky I don't have to go that route? I think a 40 day supply for one of my cats is $12.99 at Costco? My other cat that is on Felimazole and it is only a few bucks more. I'm just too lazy to it get changed to the regular non-coated kind. When I looked into the radiation treatment here in the PNW last year, it was around $3,500. I was considering doing it, but then our other cat got diagnosed as well and I thought, well how do I pick which one gets it and which one doesn't? Plus, we can't really afford it anyway.

Also, my understanding is the "in house" quick T4 results aren't super detailed and that the ones you have to send out to a lab give you more specific numbers? But maybe someone else can chime in on that?

My cat was on Tapazole for human use, a 100 pills package was just €5, and I had to use a quarter of a pill twice a day. A package was enough for nearly 7 months.
Anyway I switched to eargel three months or four into the therapy and it was around €18 each syringe at the compounding pharmacy, each syringe was good for two weeks of treatment twice a day.

The I-131 treatment at a facility far away from home (Italy has no facilities for veterinary use), cost me €950, which was what I would have paid for a year of meds and regular blood work.

 

[Antonio65]

What was the process like for the I-131 for your kitty? By all accounts it seems like there are few side effects, just have to deal with the days in isolation.

My cat was treated about 11 months after the diagnosis.
She was diagnosed in September 2016, treated in August 2017.
The first thing was pills, then we decided to use the eargel because it was easier to dose and administer. In June 2017 she was put in the list for the treatment.
She stayed 5 days at the facility, where they performed both the scintigraphy and the radio iodine injection.
She was fine during and after the treatment. She came home and didn't seem to be bothered by the treatment. She started feeling better a couple of months later, her thyroid levels returned to normal about 4 months later.