Methimazole is a prescription medication used to treat hyperthyroidism in cats.

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Methimazole Basics
Methimazole is available by prescription only. Methimazole is used to treat hyperthyroidism, or an overactive thyroid gland. Methimazole belongs to a class of drugs known as anti-thyroid agents. The thyroid hormone is responsible for regulating the body’s metabolism. When the thyroid gland produces too much of these thyroid hormones, weight loss, abnormal appetite, and heart problems occur. Methimazole is used to treat cats only. It should not be used to treat dogs. Methimazole is available in a 5 mg tablet

Methimazole Warnings
Keep out of the reach of children and pets. Methimazole should not be used in cats with known allergies to this drug. Do not use in cats that are pregnant or lactating. Do not give live vaccines while on Methimazole treatment. Blood tests must be done to check for correct dosage. Use caution in cats suffering from liver disease, immune system disease, or blood disorders. Use caution when administering Methimazole or when disposing of waste from cats taking Methimazole. Owners, especially pregnant women, should wear gloves when handling tablets or waste from cats taking Methimazole.

Methimazole Directions
Use as directed by your veterinarian. Follow the instructions printed on the prescription label. Store Methimazole at room temperature. Complete the entire prescription, even if your cat seems to be improving, unless instructed otherwise by your veterinarian. Can be given with or without food. Allow your pet access to plenty of water while giving Methimazole. Periodic blood tests are needed to monitor T4 and T3 levels. Wash your hands after administering Methimazole. Owners, especially women who are pregnant or nursing, should use caution while administering Methimazole or waste from cats taking Methimazole. In the case of a missed dose of Methimazole, give it as soon as you remember or wait until it is time to give the next dose. DO NOT GIVE A DOUBLE DOSE OF Methimazole.

If you notice any behavioral or physiological changes in your pet while giving Methimazole, contact your veterinarian immediately.

Adverse Reactions and Serious Side Effects
Adverse reactions and serious side effects are rare, but in the case of an adverse reaction or a serious side effect you should stop Methimazole treatment and seek veterinary attention. Some common adverse reactions and serious side effects are facial swelling, breathing difficulties, hives, dark urine, jaundice, blood in urine or stool, easy bruising or bleeding, chills, blistering or peeling, skin rash, or unusual weakness.

Additional information

Prescription Strength

2.5mg (Felimazole Brand), 5mg (Felimazole Brand), 5mg, 10mg