Methimazole is used to treat hyperthyroidism in cats. It has largely replaced propylthiouracil in this treatment process since it has a lower incidence of adverse side effects. Methimazole requires a prescription from your veterinarian, and is sold per tablet.
Effectively treats hyperthyroidism in cats
Affordably sold per tablet
How it works: Hyperthyroidism is a condition that occurs when the thyroid gland produces too much thyroid hormone. Methimazole inhibits the production of thyroid hormones.
Cautions: Blood tests must be done to check for proper dosage. Do not use in pregnant or nursing animals. Do not give your pet a live vaccine while giving methimazole. Contact your veterinarian immediately if your pet develops signs of an infection.
Brand Name Tapazole (Jones)
Generic Name Methimazole
What is the most important information I should know about Methimazole: Methimazole is a prescription medication not FDA approved for veterinary use; however, it is a commonly accepted practice for veterinarians to use this medication in cats. Methimazole is available as a 5mg scored tablet. The usual initial dose for cats is 5mg every 8 to 12 hours. Do not give methimazole to pregnant or nursing animals. Methimazole can increase the risk of bleeding. Methimazole can lower the blood cells that help fight infections. Your veterinarian will need to give blood tests on a regular basis to be sure these blood cells do not get too low. Do not give the pet a "live" vaccine while the pet is taking methimazole. Methimazole is needed for the life of the pet. If the medication is stopped, the symptoms will reappear.
What is Methimazole: Methimazole prevents the thyroid gland from producing too much thyroid hormone. Methimazole is used to treat overactive thyroid (hyperthyroidism). It is also used before thyroid surgery or radioactive iodine treatment. Methimazole may also be used for purposes other than those listed in this guide.
What should I discuss with my veterinarian before giving Methimazole to my pet: Tell your veterinarian if your pet has an allergy to methimazole or if your pet has liver disease, a blood cell disorder, or a weak immune system. Tell your veterinarian if the pet is pregnant or nursing. Inform your veterinarian of any other medications, including vitamins and supplements your pet may be taking while receiving methimazole.
How should this medication be given: Give this medication exactly as directed by your veterinarian. Do not give in larger amounts, or give it for longer than recommended by your veterinarian. Follow the directions on the prescription label. If you do not understand the directions ask the pharmacist or veterinarian to explain them to you. Methimazole can be given with or without food. Allow plenty of water for the pet to drink. Store methimazole at room temperature away from moisture and heat. Keep this medication away from children and pets.
What happens if I miss giving a dose: Give the missed dose as soon as you remember during the same day. However, if you don¿t remember until the next day, skip the dose you missed and give only the next regularly scheduled dose. Do not give a double dose of the medication.
What happens if I overdose the pet: Seek emergency veterinary medical treatment. Symptoms of methimazole overdose may include nausea, vomiting, upset stomach, joint pain, headache, fever, itching, swelling, and easy bruising or bleeding.
What should I avoid while giving Methimazole to my pet: Do not give the pet a "live" vaccine while the pet is taking methimazole. Contact your veterinarian at once if your pet develops signs of an infection.
What are the possible side effects of Methimazole: If any of the following serious side effects occur, stop giving methimazole and seek emergency veterinary medical attention; an allergic reaction (difficulty breathing; swelling of the lips; tongue or face; hives). Stop giving methimazole and contact your veterinarian at once if your pet develops any of these serious side effects; fever, chills, body aches; easy bruising or bleeding, unusual weakness; blood in the urine or stools; severe blistering, peeling, and skin rash; nausea, low fever, loss of appetite, dark urine, jaundice. Other less serious side effects may occur. Continue giving methimazole and talk to your veterinarian if your pet experiences headache, drowsiness, dizziness; mild nausea, or vomiting; itching; muscle, joint, or nerve pain; swelling; hair loss. Other side effects may also occur. Talk to your veterinarian about any side effect that seems unusual or bothersome to the animal.
What other drugs will affect Methimazole: Tell your veterinarian if your pet is taking theophylline (Theo-Dur), warfarin (Coumadin), digoxin (Lanoxin), a beta blocker such as atenolol (Tenormin), metoprolol (Lopressor), or propranolol (Inderal). Drugs other than those listed may also interact with Methimazole. Talk to your veterinarian or pharmacist before giving any prescription or over the counter medicines.
Where can I get more information: Your pharmacist has additional information about methimazole written for health professionals that you may read.
Call your veterinarian for medical advice about any side effects to your pet. You may report side effects to the FDA at 1-800-FDA-1088.
Methimazole is a prescription medication used by veterinarians to treat overactive (hyper) thyroid in cats.
Methimazole is not FDA approved for use in veterinary medicine; however, it is a commonly accepted practice for veterinarians to prescribe this medication for cats.
Methimazole is also used before thyroid surgery or radioactive iodine treatment.
Periodic blood tests will be necessary while the cat is taking this medication.
Tip: Do not use in pregnant or nursing animals. Methimazole can be given with or without food.
The usual initial dose varies from 2.5-5mg 2 or 3 times a day. Periodic blood testing is required to monitor liver function and for any toxic effects on blood cells
Storage: Store methimazole at room temperature, away from moisture and heat.
Our cat has been on this medicine for 2 years and it wasn't until recently we discovered this pill (white, no coating) that has an indentation down the middle that makes it easy to divide when he only needs 1/2 pill. We were not able to get this from our vet.
My cat was eating everything in site that he could before I found out he had a thyroid problem and was put on Methimazole, he is a normal eater now so must be feeling better. He is 17 and going strong.
My cat was diagnosed with a hyperactive thyroid recently and after getting her on these meds, she's like a new cat! Spry, happy. exploring a lot more, and even nicer to my other meows. You can tell she definitely feels better and I'm thankful my vet prescribed her this medication.
Med good, service mixed
I've been using PetMeds to get my cat's Methimazole because it was less expensive than drugstores, and it always arrives promptly, so in that sense it's good. At first I was pleasantly surprised to find they enclosed a cat treat with my orders. However, for some reason they started sending a dog biscuit instead of catnip, and after notifying them 3 or 4 times, I got an email from customer service. They apologized and said a cat treat was on its way. It never arrived, and on this latest order, there was no pet treat of any kind enclosed. So the meds come in a timely manner, but my cat gets slighted - that's why I say service is mixed.
Methimazole seem to keep My cat in check. Every now & Then, she'll not do well, but at 17, She still acts like a kitten.
We have 3 elderly cats and I want to make sure she gets it instead of the other two. The ear application seems like a good way. It is working so far but is a bit pricey. I was curious to see if you offered it and what the cost is. Thanks!
4 months ago
Yes, we do carry the transdermal methimazole !! Please call our customer service department for prices.
My cat Snowy was put on 2.5 mg of Methimazole twice a day. His blood was tested after one month and his T4 levels were back to normal. He became more active with a better appetite and didn't act at all like the 19 year old that he is. Now almost 2 months on the medication he is getting red raised spots in several places on the back of his neck. Some have scabs so I think he must be scratching them. Could this be a reaction to the Methimazole and if so why would it take so long to show itself?
Considering that your pet only started having this problem now and he's been on the medication for awhile it may not be a result of the medication. However, contact your veterinarian as they may want to examine your pet to determine the cause and if treatment is necessary.
This information sheet is for educational purposes only and is intended to be a supplement to, and not a substitute for, the expertise and professional judgment of your veterinarian. The information is NOT to be used for diagnosis or treatment of your pet. You should always consult your own veterinarian for specific advice concerning the treatment of your pet. The information is not intended to cover all possible uses, directions, precautions, warnings, allergic reactions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for your pet. It is not a substitute for a veterinary exam, and it does not replace the need for services provided by your veterinarian. Note: Any trademarks are the property of their respective companies.