What is Methimazole?
Methimazole may also be used to protect the kidneys in dogs receiving cisplatin, an anti-cancer drug.
Who is it for?
What are the benefits?
How does Methimazole work?
How is it given?
Blood levels of thyroid hormone will be checked by your veterinarian at regular intervals, and the dose increased or decreased as needed. The lowest effective dose should be used.
This medication should only be given to the pet for whom it was prescribed.
What results can I expect?
What form(s) does it come in?
Common Drug Name
What should I discuss with my veterinarian while considering Methimazole?
Tell your veterinarian if your pet has a blood disease, liver disease, or autoimmune disease; or may be pregnant, is nursing, or if you intend to breed your pet.
Notify your veterinarian of any other medications or supplements your pet is taking, and also if your pet has had any reactions to previous medications.
What should I do if I miss a dose?
What is the most important information I should know?
Who should not take it?
Use with extreme caution in pregnant or lactating animals (females nursing their young). If the mother is receiving Methimazole, place the young on milk replacer after they have received the colostrum (first milk immediately after birth).
In addition to monitoring of thyroid hormone levels, laboratory tests to check liver and kidney function and blood cell counts may be performed before starting treatment and then regularly thereafter.
What side effects may be seen when taking Methimazole? [Back]
May see loss of appetite, vomiting, or lethargy. These usually occur within the first two weeks of treatment and may stop even with continuation of treatment.
Less common side effects include liver problems resulting in the above signs plus yellowing of the gums, skin, or eyes; itching of the face, resulting in scratching; or bleeding tendencies. Your veterinarian will determine if these effects necessitate stopping the medication and treating with surgery or radioactive iodine therapy.
Treatment with Methimazole may unmask hidden kidney disease.
Rarely, you may see the development of myasthenia gravis, a neuromuscular disease that severely weakens muscles and may cause difficulty swallowing. If your pet is unusually tired, has a fever (temperature over 103°F), or shows signs of bruising or bleeding, contact your veterinarian immediately.
If your pet experiences an allergic reaction to the medication, signs may include facial swelling, hives, scratching, and sudden onset of diarrhea, vomiting, shock, seizures, pale gums, cold limbs, or coma. If you observe any of these signs, contact your veterinarian immediately.
How is it stored?
What should I do if I know of or suspect there has been an overdose?
What should I avoid when giving my pet Methimazole?