Compounded Methimazole Suspension

What is hyperthyroidism?

Hyperthyroidism results when the thyroid gland over-produces thyroid hormones. It’s the most common endocrine disease of cats older than 8-years-old. (An endocrine disease is a disease of the organs that make and secrete hormones.)

In almost 99 percent of the cases, hyperthyroidism is caused by a benign (non-cancerous) tumor of the thyroid gland. The butterfly-shaped thyroid gland is located in the neck, with one lobe on each side. It plays an important role in regulating the body’s “engine,” or metabolic rate. When the thyroid gland produces an excessive amount of thyroid hormones, it causes the cat’s “engine” to run at an abnormally high speed. This high metabolic rate negatively affects almost all of the cat’s organs.

What are the signs of hyperthyroidism in cats?

The most common sign of hyperthyroidism in cats is weight loss despite an increased appetite. Other common signs include vomiting, diarrhea, hyperactivity, drinking and urinating more than normal, and an unkempt hair coat. Because the disease develops gradually, signs are often easy to miss at first.

Hyperthyroidism often leads to high blood pressure (hypertension) and heart disease. The high blood pressure is due to the increased pumping pressure of the heart. In some cats, the blood pressure becomes so high that the retina detaches from the back wall of the eye, resulting in sudden blindness. Heart disease develops because the heart must pump faster and more forcefully to meet the body’s increased metabolic demands (due to the cat’s revving engine). To compensate for this increased workload, the muscles of the heart thicken, causing the heart to enlarge and eventually fail. Untreated hyperthyroidism is almost 100 percent fatal.

How does Felimazole work?

Methimazole, the active ingredient in Felimazole, is an antithyroid drug that works by blocking the production of thyroid hormones.

 

Information on this medication quoted from fda.gov