Methimazole Treatment for Cats: A Veterinary Analysis

Methimazole Treatment for Cats: A Veterinary Analysis

Methimazole is a commonly used antithyroid thioamide for treating hyperthyroidism in cats, a condition where the thyroid gland becomes overactive and produces too much thyroid hormone.

The typical dosage of Methimazole for cats is 2.5 mg orally every 12 hours, with adjustments made in 2.5 mg increments. The maximum total dosage is 20 mg per day, divided into doses not exceeding 10 mg at a single administration.

Methimazole is usually administered orally, in coated tablet form available in 2.5 mg and 5 mg strengths. A recommended method of administration is to hide the tablet in a small amount of the cat’s favourite soft food to ensure full consumption, especially in older or finicky cats. Handlers should wash their hands thoroughly after giving the medication to avoid unintentional exposure.

Because methimazole can be absorbed through the skin, the transdermal formulation is available for more accurate dosing. This viscous gel may appear clear or translucent and comes in a metered dispenser. Transdermal gel should be applied to a hairless surface of a cat's skin, such as the inner surface of the ear pinna (ear flap), and worn gloves should be used when applying the medication.

It is important to note that methimazole works by preventing the formation of thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3). However, this medication can cause various side effects in cats, such as anorexia, vomiting, weight loss, weight gain, itchiness (especially of the face), weakness, lethargy, and changes to organ function, including inflammation of the liver (hepatitis) and decrease in kidney function.

Cats who are on some medications before starting methimazole may need to adjust their dose after their thyroid disease is controlled. Some parasite preventatives should not be given with methimazole, and administration with phenobarbital or anticoagulant medications may decrease their efficacy.

Cats who are pregnant or nursing should not be given methimazole. Some cats can develop blood abnormalities when taking methimazole, in which case the medication should be discontinued. Over time, cats may require more methimazole to manage their hyperthyroidism, and the medication may eventually become ineffective or require a dose so high that it causes unwanted side effects.

It is essential to have ongoing veterinary monitoring to regularly assess thyroid function and adjust dosage as hyperthyroidism can progress over time. Side effects and thyroid hormone levels must be evaluated periodically to ensure safe and effective treatment.

The FDA-approved brand name for methimazole for cats is Felimazole, which was granted approval in May 2009. Generic formulations of methimazole can be used at the discretion of your veterinarian. A month of generic methimazole tablets can cost between $5-50, while liquid and transdermal formulations may be more expensive, costing between $40-75 per month.

Cats treated for hyperthyroidism are at an increased risk for developing thyroid carcinoma, a cancerous thyroid tumor. Hyperthyroidism in cats can cause symptoms such as weight loss, increased appetite, vomiting, increased thirst and urination, changes in behaviour, a heart murmur, increased blood pressure, and enlargement of the thyroid gland.

In conclusion, Methimazole is a crucial medication for managing hyperthyroidism in cats. Regular monitoring, careful dosage adjustments, and open communication with your veterinarian are key to ensuring the best possible outcome for your feline friend.

1. Science has made advancements in treating hyperthyroidism in cats with Methimazole, a commonly used antithyroid thioamide.
2. This medication works by preventing the formation of thyroid hormones such as thyroxine (T4) and triiodothyronine (T3).
3. It is crucial to note that Methimazole can cause various side effects in cats, including anorexia, vomiting, weight changes, itchiness, weakness, and lethargy.
4. Cats who are on some medications before starting Methimazole may need to adjust their dose after their thyroid disease is controlled.
5. Cats treated for hyperthyroidism are at an increased risk for developing thyroid carcinoma, a cancerous thyroid tumor.
6. The FDA-approved brand name for Methimazole for cats is Felimazole, and generic formulations can be used at the discretion of your veterinarian.
7. A month of generic Methimazole tablets can cost between $5-50, while liquid and transdermal formulations may be more expensive.
8. Ongoing veterinary monitoring is essential for regularly assessing thyroid function and adjusting dosage as hyperthyroidism can progress over time.
9. Side effects and thyroid hormone levels must be evaluated periodically to ensure safe and effective treatment.
10. Because methimazole can be absorbed through the skin, a transdermal formulation is available for more accurate dosing.
11. Cats who are pregnant or nursing should not be given Methimazole.
12. Over time, cats may require more Methimazole to manage their hyperthyroidism, and the medication may eventually become ineffective or require a dose so high that it causes unwanted side effects.
13. Methimazole should be administered orally, in coated tablet form available in 2.5 mg and 5 mg strengths, and a recommended method of administration is to hide the tablet in a small amount of the cat’s favorite soft food.
14. Some cats can develop blood abnormalities when taking Methimazole, in which case the medication should be discontinued.

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