Please share your Methimazole experience..

[WhiteAilly]

Hello, our 19 year old female cat named Angel recently had a senior panel checkup after her brother Jazzi suddenly became ill and passed away last month. (Seemed sudden, but assuming the issues were developing which we did not catch sooner.) We didn't want another horrible surprise, we took her for a thorough checkup. The Vet said that her test results came out pretty good for 19 year old, no kidney issue like her brother had, but detected a mild case of Hyperthyroid, so he prescribed her Methimazole to take for a few weeks. Since it was found at the early stage, he said he would start her with a small dosage of 2.5 mil twice a day. The medication came with some serious side effects warning and we first got very scared but the vet assured me that he had never seen a cat with a side effect with this medication. She had been taking it for the last 2 weeks and the vet was right, we hadn't seen any side effects and actually it seemed like the med was working since her weight improved and she seemed content and happy. But one day during the 2 weeks, she did not eat and seemed under the weather, but the next day, she was back to herself. Then yesterday, the same thing, she didn't want to eat. She still has a very healthy #2. We noticed that she started to drink water out of her water bowel more often than before in a last few days....which we now know is not a good thing after seeing her brother excessively drinking out of the water bowel towards the end of his time. I am hoping that the medication is not affecting her kidney negatively. Since early this morning, she has been throwing up, first a clear liquid, then orange liquid, and the tiny breakfast she ate this morning – separate times. She is not looking happy. I am wondering if the medication is now starting to give her some side effects since vomiting and lack of appetite are listed among its side effects. I'm not sure if I should stop giving her the med. She actually went to see the Vet on Friday for a monitoring checkup. The result should be in tomorrow. We feel that she is under a good care by our new vet, who is very compassionate. I'm just wondering if anyone can share the experience with Methimazole out there. If anyone has any natural remedy against Hyperthyroid that is working, I would like to hear about it. Thank you very much.

 

[daftcat75]

Please don’t change her medicine without discussing this with your vet. Please discuss all of this with your vet as soon as you can. How is her urination? Is she peeing more or more often? If her eating is sporadic and her drinking and peeing is excessive, she may be in danger of getting dehydrated. If she shows any signs of lethargy and weakness, please take her down to the vet for fluids and a recheck examination. Things can change quickly with a senior cat.

 

[WhiteAilly]

Please don’t change her medicine without discussing this with your vet. Please discuss all of this with your vet as soon as you can. How is her urination? Is she peeing more or more often? If her eating is sporadic and her drinking and peeing is excessive, she may be in danger of getting dehydrated. If she shows any signs of lethargy and weakness, please take her down to the vet for fluids and a recheck examination. Things can change quickly with a senior cat.

Thank you very much for your reply. She is not peeing excessively. I will be calling her vet tomorrow morning and see what he suggests. Hoping that the Friday's test result will be good.

 

[molly92]

Methimazole can have some detrimental side effects. Also, hyperthyroidism is a progressive disease that will get worse over time, so you could also be seeing more symptoms of that. Vomiting and increased thirst are possible symptoms. Lack of appetite is unusual for hyperthyroidism, so it could be that she's just on too high a dose. Definitely something to talk to your vet about.

BUT, by far and away the best treatment for hyperthyroidism is actually a cure: I-131 radioiodine therapy. It is very safe and effective, making hyperthyroidism an unusual disease for having such a targeted cure.

Hyperthyroidism is when part of the cells of the thyroid start dividing and growing rapidly and don't stop. This creates a tumor that will continue to grow in size for the rest of the cat's life without surgery or radioiodine therapy. In rare cases it can mutate to become cancerous, but that is uncommon. With extra thyroid comes extra thyroid hormones, which are the hormones that tell the body to "go." Burn calories quickly, pump the heart fast, push urine out fast, etc. This is hard on the body. Fortunately, the thyroid is the only part of the body that needs iodine. All the iodine in the system gets sucked into the thyroid for it to use. If you inject a cat with a radioactive isotope of iodine, the extra-hungry part of the thyroid sucks it up, but the radioactivity kills off the overactive cells. Since nothing else uses iodine, the radioiodine passes through the rest of the cat's system and out through their urine without causing any damage elsewhere. Surgery, the other cure, to cut out that part of the thyroid, is obviously much riskier on an elderly cat.

The drawbacks include expense (generally $1000-$2000 USD) and a period of isolation that the cat has to go through after the injection. Vets can't release the cat to you until they reach the legal levels for radioactivity, which usually takes a few days to a week. After that you have to be careful with their used litter for about a month. Only vets with trained technicians and facilities can do it, so you may need to ask around.

I did this with my 16 year old and I was so glad I did, even though she only lived another year and a half. She was obviously much more comfortable and I didn't feel her heart pounding out of her chest anymore from the day she came home. Some vets don't even bring it up because so many clients balk at the idea of paying for an expensive treatment for a 19 year old cat, but personally I think it's worth it.

The alternatives are methimazole, which helps with the symptoms but does not stop the tumor from growing and will need to be adjusted in dose as the disease progresses, or starving the thyroid of iodine with a prescription diet. That last one also does not stop the tumor from growing, and is not usually recommended because it's not a super effective method.

There is an interesting quirk with hyperthyroidism that because the urine is being pushed through the kidneys so hard, signs of kidney disease often do not show up on tests until the hyperthyroidism is cured. As both hyperthyroidism and kidney disease are so common in elderly cats, it's also very common to have both. The drinking excessively, lack of appetite, and vomiting could also be signs of kidney disease. Perhaps you can talk to your vet about doing a period of taking her of the methimazole and seeing if you can rule it out. Either way, definitely ask them about radioiodine treatment as well!

 

[Twylasmom]

Ask your vet about transdermal methimazole (administered in the ear). It can work just as well and because it isn't ingested causes little to no side effects, particularly the nausea or stomach upset. I highly recommend it. It can be ordered from an online pharmacy or the vet might have a local compounding pharmacy they use. If you need to keep your cat on the oral form until you get the transdermal, ask about antinausea and/or an appetite stimulant depending on the side effects.

 

[fionasmom]

Fiona was on this for several years, although if I had it to do over again, I would probably look into the I-131 treatment. We had no reaction to the medication.....but they can occur so I would make a big deal out of this with the vet to make sure that if she has to stay on this it is not responsible for the side effects that she is having.

 

[white shadow]

.
Hi WhiteAilly.

I haven't had to use methimazole (yet), but I'd like to try to add a little to your understanding of all of this.

Right off the bat, you said that you are "hoping that the medication is not affecting her kidney negatively." Methimazole will not damage her kidneys. As cats age, some will experience reduced kidney function, like Angel's brother did. (Cats, like humans, "come" with sufficient kidney capacity for a lifetime, but kidneys can't regenerate. Kidney function insufficiency is common in elderly cats and humans.) When a cat has hyperthyroidism, their body systems are in a type of 'overdrive', pushed 'to the limit'. (And, if the hyperthyroidism is left untreated, that hyper activity itself will inevitably cause death - because those body systems cannot sustain such intense/unnatural pace indefinitely.) So, if there's to be any hope at all, the hyper-T must be addressed and treated.

I see that molly92 has just posted......let me add a little to that. She also spoke about this 'overdriving' of the body's systems and how it is "hard on the body"......well, as I said above, it is also invariably fatal if left untreated.

So, when the hyper-T is treated and all systems 'slow down' and 'return to their normal speed', cats who had reduced kidney function all along (but hidden by the thyroid's drive) can be found/diagnosed to have kidney disease, which may be 'mild'/early stage to advanced.

Talk about finding oneself between a rock and a hard place! The 'trick', though, I believe, is fine-tuning the medication so that it's effective with minimum/least side effect.

One point about Angel's methimazole dosing......you described it as a "small dosage of 2.5 mil twice a day". Now, as it happens, the recommended starting dose can be half that amount (1.25mg twice daily) and adjusted upwards if necessary. If you want to present that to your Vet, it's here and from the Veterinarian who 'discovered' Feline Hyper-T 40 years ago here. In my book, I'd be looking for the lowest effective dose...so as to minimize side effects. (that said, it is well known that these side effects usually diminish over a short time)

If you want a reliable, plain-language A-Z coverage of Hyper-T, there's one here, and inside that page, methimazole is detailed here.

One last thought. If you are or might be considering the surgery or the radio iodine treatment (both being 'final'/curative), make sure to read the "Medication Trial" section of that coverage, found here. (if one of mine were in this position at age 19, I'd be using the drug first)

Whew !

Oh........I'd be remiss if I didn't tell you that............we would neverrrrrrrr refuse pics of Ms Angel !
.

 

[WhiteAilly]

Methimazole can have some detrimental side effects. Also, hyperthyroidism is a progressive disease that will get worse over time, so you could also be seeing more symptoms of that. Vomiting and increased thirst are possible symptoms. Lack of appetite is unusual for hyperthyroidism, so it could be that she's just on too high a dose. Definitely something to talk to your vet about.

BUT, by far and away the best treatment for hyperthyroidism is actually a cure: I-131 radioiodine therapy. It is very safe and effective, making hyperthyroidism an unusual disease for having such a targeted cure.

Hyperthyroidism is when part of the cells of the thyroid start dividing and growing rapidly and don't stop. This creates a tumor that will continue to grow in size for the rest of the cat's life without surgery or radioiodine therapy. In rare cases it can mutate to become cancerous, but that is uncommon. With extra thyroid comes extra thyroid hormones, which are the hormones that tell the body to "go." Burn calories quickly, pump the heart fast, push urine out fast, etc. This is hard on the body. Fortunately, the thyroid is the only part of the body that needs iodine. All the iodine in the system gets sucked into the thyroid for it to use. If you inject a cat with a radioactive isotope of iodine, the extra-hungry part of the thyroid sucks it up, but the radioactivity kills off the overactive cells. Since nothing else uses iodine, the radioiodine passes through the rest of the cat's system and out through their urine without causing any damage elsewhere. Surgery, the other cure, to cut out that part of the thyroid, is obviously much riskier on an elderly cat.

The drawbacks include expense (generally $1000-$2000 USD) and a period of isolation that the cat has to go through after the injection. Vets can't release the cat to you until they reach the legal levels for radioactivity, which usually takes a few days to a week. After that you have to be careful with their used litter for about a month. Only vets with trained technicians and facilities can do it, so you may need to ask around.

I did this with my 16 year old and I was so glad I did, even though she only lived another year and a half. She was obviously much more comfortable and I didn't feel her heart pounding out of her chest anymore from the day she came home. Some vets don't even bring it up because so many clients balk at the idea of paying for an expensive treatment for a 19 year old cat, but personally I think it's worth it.

The alternatives are methimazole, which helps with the symptoms but does not stop the tumor from growing and will need to be adjusted in dose as the disease progresses, or starving the thyroid of iodine with a prescription diet. That last one also does not stop the tumor from growing, and is not usually recommended because it's not a super effective method.

There is an interesting quirk with hyperthyroidism that because the urine is being pushed through the kidneys so hard, signs of kidney disease often do not show up on tests until the hyperthyroidism is cured. As both hyperthyroidism and kidney disease are so common in elderly cats, it's also very common to have both. The drinking excessively, lack of appetite, and vomiting could also be signs of kidney disease. Perhaps you can talk to your vet about doing a period of taking her of the methimazole and seeing if you can rule it out. Either way, definitely ask them about radioiodine treatment as well!

Thank you very much for all the valuable information on the treatments of Hyperthyroidism. We just lost her brother and we are not ready to lose her too soon, so whatever can work for her, we will try. When I call the vet tomorrow, I will ask him about the I-131 radioiodine therapy.

 

[WhiteAilly]

Ask your vet about transdermal methimazole (administered in the ear). It can work just as well and because it isn't ingested causes little to no side effects, particularly the nausea or stomach upset. I highly recommend it. It can be ordered from an online pharmacy or the vet might have a local compounding pharmacy they use. If you need to keep your cat on the oral form until you get the transdermal, ask about antinausea and/or an appetite stimulant depending on the side effects.

Thank you very much for your reply. Yes, I will definitely ask our vet about the kind you can administer in the ear. I think the med is upsetting her tummy. She can't keep her food in since this morning, but she wants to eat....

 

[WhiteAilly]

Fiona was on this for several years, although if I had it to do over again, I would probably look into the I-131 treatment. We had no reaction to the medication.....but they can occur so I would make a big deal out of this with the vet to make sure that if she has to stay on this it is not responsible for the side effects that she is having.

Thank you very much for your reply. I will be asking our vet about the i-131 treatment tomorrow.

 

[WhiteAilly]

.
Hi WhiteAilly.

I haven't had to use methimazole (yet), but I'd like to try to add a little to your understanding of all of this.

Right off the bat, you said that you are "hoping that the medication is not affecting her kidney negatively." Methimazole will not damage her kidneys. As cats age, some will experience reduced kidney function, like Angel's brother did. (Cats, like humans, "come" with sufficient kidney capacity for a lifetime, but kidneys can't regenerate. Kidney function insufficiency is common in elderly cats and humans.) When a cat has hyperthyroidism, their body systems are in a type of 'overdrive', pushed 'to the limit'. (And, if the hyperthyroidism is left untreated, that hyper activity itself will inevitably cause death - because those body systems cannot sustain such intense/unnatural pace indefinitely.) So, if there's to be any hope at all, the hyper-T must be addressed and treated.

I see that molly92 has just posted......let me add a little to that. She also spoke about this 'overdriving' of the body's systems and how it is "hard on the body"......well, as I said above, it is also invariably fatal if left untreated.

So, when the hyper-T is treated and all systems 'slow down' and 'return to their normal speed', cats who had reduced kidney function all along (but hidden by the thyroid's drive) can be found/diagnosed to have kidney disease, which may be 'mild'/early stage to advanced.

Talk about finding oneself between a rock and a hard place! The 'trick', though, I believe, is fine-tuning the medication so that it's effective with minimum/least side effect.

One point about Angel's methimazole dosing......you described it as a "small dosage of 2.5 mil twice a day". Now, as it happens, the recommended starting dose can be half that amount (1.25mg twice daily) and adjusted upwards if necessary. If you want to present that to your Vet, it's here and from the Veterinarian who 'discovered' Feline Hyper-T 40 years ago here. In my book, I'd be looking for the lowest effective dose...so as to minimize side effects. (that said, it is well known that these side effects usually diminish over a short time)

If you want a reliable, plain-language A-Z coverage of Hyper-T, there's one here, and inside that page, methimazole is detailed here.

One last thought. If you are or might be considering the surgery or the radio iodine treatment (both being 'final'/curative), make sure to read the "Medication Trial" section of that coverage, found here. (if one of mine were in this position at age 19, I'd be using the drug first)

Whew !

Oh........I'd be remiss if I didn't tell you that............we would neverrrrrrrr refuse pics of Ms Angel !
.

Thank you very much for all the great information! I am sorry, I made a mistake with the dosage she is getting. It's only 0.25 mil twice a day, not 2.5 mil. The vet is going to tell me tomorrow if she can stop taking it or might have to increase the dosage. I'm now going to explore the links in your message. I'm asking her brother up in the kitty heaven to look over his sister so she won't join him too soon. Here is our Angel.

 

[WhiteAilly]

Hi, just a quick update on Angel. The test results came in and the vet said her thyroid is now back to normal and she also has no kidney issue. He is recommending to keep giving her the same dosage 0.25 mil twice a day for life to maintain the health of her thyroid and put her on the strict Kidney support diet so she can also maintain her kidney health. She did not vomit last night dinner but did vomit twice today once in a morning and again in the late afternoon. She had her dinner a little while ago and I am crossing my fingers that she won't vomit again. Our vet's suggestion was to see how she does with eating for a couple of weeks but if the vomiting continues and she gets weaker, then we will have to find another possible cause with X-ray and/or ultrasound since her thyroid and kidney are fine. She looks lonely and we are wondering if she is still depressed from the loss of her brother. That's understandable since they were so close, but can the depression cause a stomach upset? Hope her tummy issue will go away soon. Thank you very much again for all your inputs.