What is Methimazole for Cats?
Methimazole, marketed under names like Felimazole, is an antithyroid medication used to treat hyperthyroidism in cats, a condition where the thyroid produces excessive hormone levels. It is commonly prescribed for cats over ten years old. This medication blocks thyroid hormone production to help control symptoms like weight loss, excessive thirst, and increased urination. Methimazole is often used as a long-term solution, though it doesn’t cure the underlying issue, which is typically a benign tumor on the thyroid gland.
Active Ingredients
The active ingredient in Methimazole is methimazole itself, which works by inhibiting the production of thyroid hormones. This helps reduce symptoms associated with hyperthyroidism, such as rapid heart rate, weight loss, and excessive thirst. The medication interferes with thyroid peroxidase, an enzyme involved in the synthesis of thyroid hormones. Over time, this reduces the level of circulating hormones in your cat’s bloodstream.
How to Use Methimazole for Cats
Administration:
Methimazole is available in various forms, including tablets, oral liquids, transdermal gels, and compounded treats. The standard starting dose is typically 2.5 mg twice a day, but it may be adjusted based on your cat’s response.
- Tablets or Liquids: Administer orally twice daily.
- Transdermal Gel: Apply a prescribed dose to the cat’s inner ear, using gloves or finger cots.
- Compounded Treats: Give according to prescription, often flavored for your cat’s preference.
Storage Instructions:
Store Methimazole at room temperature and protect it from moisture. If compounded, follow the pharmacy’s instructions, as some forms may require refrigeration.
Methimazole Indications & Contraindications
Indications:
Methimazole is primarily indicated for treating hyperthyroidism in cats, particularly in older cats showing symptoms such as weight loss, increased appetite, and excessive thirst.
Contraindications:
Methimazole should not be used in cats with liver disease, kidney disease, autoimmune disorders, or if pregnant. It is also not suitable for cats with certain blood disorders, such as anemia.
Effectiveness
Methimazole is generally effective in managing hyperthyroidism, controlling symptoms in many cats. It doesn’t cure the disease but can manage hormone levels long-term. Studies show that most cats respond positively, but regular blood monitoring is crucial to ensure effectiveness and prevent complications like liver damage or kidney strain.
Adverse Reactions
Common side effects of Methimazole include:
- Vomiting
- Diarrhea
- Reduced appetite
- Itchy skin or skin lesions
- Weight loss
More severe reactions include liver disease, low white blood cell counts, and blood-clotting issues. Contact your veterinarian immediately if your cat exhibits weakness, jaundice, or labored breathing.
Dosage & Safety Information
Dosage:
The typical dose is 2.5 mg every 12 hours, adjusted based on the cat’s size and condition. For instance, a 10 lb. cat may start with this dose, but larger or smaller cats may require adjustments.
Safety:
Wear gloves when administering the medication, especially in transdermal form. Keep Methimazole away from children, and ensure it’s stored in a secure, dry place. Discard expired medications responsibly.
What Happens if I Miss a Dose?
If you miss a dose, administer it as soon as you remember. If it’s close to the next scheduled dose (within 6 hours), skip the missed dose and resume the regular schedule. Do not double the dose.
Can It Be Used on Kittens?
Methimazole is generally not recommended for kittens, as hyperthyroidism typically affects older cats. In rare cases where it’s needed, the veterinarian will provide a carefully adjusted dosage based on the kitten’s size and age.
Can It Be Used on Pregnant Cats?
Methimazole is not recommended for pregnant cats due to potential risks, including adverse effects on fetal development. Consult your veterinarian for alternative treatment options if your pregnant cat develops hyperthyroidism.
Methimazole Reviews
Cat owners have mixed reviews of Methimazole. Many report improvements in their cat’s symptoms, particularly weight stabilization and reduced thirst. However, some note challenges with administering the medication, especially with picky cats. Side effects like vomiting and lethargy are commonly reported, but most clear up over time or with dosage adjustments.
More Questions about Methimazole
Q: Can Methimazole cure hyperthyroidism in cats?
A: No, Methimazole controls the condition but does not cure it. More definitive treatments, like radioactive iodine therapy, may be needed for permanent results.
Q: How long does my cat need to take Methimazole?
A: Most cats require lifelong Methimazole treatment unless a more permanent option is pursued, like surgery or radioactive iodine.
Methimazole Cost
The cost of Methimazole varies depending on the form and the pharmacy. A 30-day supply of Felimazole typically costs between $20 and $40, while compounded transdermal gels or treats may be more expensive. Generic human Methimazole tablets are sometimes used to reduce costs but should be discussed with a veterinarian.
Where to Purchase Methimazole
Methimazole is available through most veterinary clinics and pet pharmacies, including online platforms. Prescription is required, so your veterinarian will guide you on where to purchase. Some compounding pharmacies offer flavored options or transdermal gels tailored to your cat’s preferences.