Do you take methimazole? I have a question!

This forum is for cat lovers seeking everyday advice and suggestions on health-related issues. Remember, however, that advice on a public forum simply can't be a substitute for proper medical attention. Only your vet can say assuredly what is best for your cat.

Kaci- Sunshine - Beloved- Angel

Sugar 'n Spice
Purred: Fri Dec 12, '08 9:07am PST 
I've just been diagnosed with hyperthyroidism and have started taking 5 mg of methimazole (tapazole) a day (2.5 mg. twice a day).

I've been told by others (who are not vets) that this is too high for a starting dosage. They say I should start at 2.5 mg once a day. I like my vet and trust her and would never think to question her about this, but now a seed of doubt has been planted in my mind.

To all kitties who are taking methimazole or tapazole, can you tell me what your starting dose was? Was it higher or lower than 5 mg.? Did you start at a low dose and then steadily increase it? Any side effects? Did the methimazole cause any damage to your liver or blood cells?

Edited by author Fri Dec 12, '08 9:19am PST


Alaidh - my little- angel

The only real- cat is a grey- cat!
Purred: Fri Dec 12, '08 7:37pm PST 
KC, I invited you to join Olde Furts. A whole bunch of us there have hyperthyroidism and can probably give you some advice...or at least share their stories!


Lazy, Lazy, Lazy
Purred: Fri Dec 12, '08 8:59pm PST 
The amount of methimazole you need depends entirely on your blood values. Your vet knows what they are doing. Many cats start at this dose. Some take 5mg twice a day. If you had faith in your vet before this then you should now too.

Kaci- Sunshine - Beloved- Angel

Sugar 'n Spice
Purred: Fri Dec 12, '08 10:36pm PST 
Thank you Hunter! I had no idea how a vet decides on a starting dosage and now I know it's determined by blood values. We're all different and have different medical profiles. What you say makes a lot of sense. I totally trust my vet and had no reason to question or doubt anything until I went to another website and some people there who have no veterinary degree and absolutely no qualifications whatsoever sounded like they really knew what they were talking about and told me our vet should start with a lower dose. They managed to scare me.

My vet did explain that some cats have side effects that usually go away after a few weeks and there are cases where a few cats do have very bad reactions to the medication. I know what to look out for. Also, KC will be getting a blood test in 3 weeks to make sure she's OK.

Alaidh, thank you for the group invite! big grin


Lazy, Lazy, Lazy
Purred: Sat Dec 13, '08 10:04am PST 
It's true that some cats can have side effects to the meds and you should report them to your vet as you notice them. They may decide to change your daily amount if you are having issues. Your blood test in 3 weeks will tell your vet if the dose you are on is adequate or too much. Many purrs to you!!!


RESPECT The- Star!
Purred: Sat Dec 13, '08 2:59pm PST 
I have no experience with hyperthyroidism or methimazole, but alot of
medicines and doseages, go by the weight of the cat, and the severity of
the disease. What works for one cat, may not work for another.

I am glad you like your vet and trust her, that is very important, when you
have a special needs cat. But, you should never ever be afraid to ask
questions about the disease, the prognosis, the medication, etc.

You are not questioning her, you are asking questions, to learn and
understand about the disease and treatments. This is actually very

When my show kitten was diagnosed with HCM, you would not believe the
number of questions I asked of vets, breeders, anybody that would help me,
most were willing to, and it gave me a greater understanding of the disease
and the treatments and care, and I did a ton of research on my own. And
now I am pretty much an expert, lol, and can help others.

If you don't already, I highly recommend you suscribe to Cat Fancy. It has
alot of good health articles in there and alot of contact info.

Best of luck with your kitty.

smilesmilesmilebig grinbig grinbig grin


Purred: Sun May 19, '13 3:05pm PST 
Hi folks - I've just been diagnosed with Hyperthyroid. I've been taking 1.25mg twice a day of Methimazole in chewy pill form for a couple of weeks but just switched over to the "transdermal gel pen" today. I feel sluggish & my right eye has a small bit of white pus weeping out the inner corner. I know sluggishness can be a side effect but what about the eye thing? Thanks, Amira


I yowl,- therefore I am
Purred: Mon May 20, '13 9:39pm PST 
The eye sounds totally unrelated to the thyroid issue. I am taking 5mg tabs. At 2.5mg, I still couldn't gain weight and was ravenous. 1.25mg sounds like a low dose to make anyone sluggish. Hyperthyroidism makes you hypertensive. Maybe the infection in your eye is making you feel sluggish? Try neosporin in the eye. smile