side effects of Methimazole

Question
Good morning
My 10 year old cat has developed hyperthyroidism.  After 2 and a half weeks  she has started. one or two bouts of  vomiting.  between  3 and 4 am  only bringing up foamy spit, not food.  She eats at 5 am and 5 pm and i put 2.5 mg in each feeding.  I tried no med one evening still had issue. Started some hair ball med yesterday to see if thats the problem?  
My vet said just stop and we will try ear  absorption ,but i have been researching and I see so many opinions , some say stop then start smaller doses, and I dont see this as a severe enough reaction to just give up on it.. Everything else is normal, with my Annamae. Also read about new canned food . I do not want to do surgery , and radioactive treatment too costly. Thank you for any advice.   Gina Piche

Answer
Vomiting is the most common side effect of this medication. Even one night without it won't stop the vomiting because it takes more than one night to remove the drug from the bloodstream.

Ear absorption is fairly good and there are usually less side effects from that then there are from the pills.

I doubt if she is having hair-ball issues- so don't complicate things by pushing a bunch of that down her. I don 't know which food you are referring too unless it's the Hills brand food.

I would just go with what your vet is telling you and do the ear gel.

That will probably help a lot to curb the vomiting.