Problems With Tapazole Use for Cats

Tapazole will treat, not cure, hyperthyroidism.
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If Fluffy has been diagnosed with a hyperactive thyroid, your vet has likely given you recommendations for treatment. Among the options for treating hyperthyroidism is the drug Tapazole, often known by its generic name, methimazole. Tapazole is a treatment and not a cure, and it has advantages and disadvantages.

How Tapazole Works

Tapazole works by decreasing the amount of hormone the thyroid produces. It can be given orally or administered to the hairless inner tip of Fluffy's ear via a transdermal gel. Administration may be scheduled one to three times a day, depending on your cat's thyroid level. It takes several weeks of administration to regulate your dog's thyroid hormones to a normal level.

Advantages to Tapazole

Treating hyperthyroidism with Tapazole has some benefits. Compared to radiotherapy and surgery, medication is less expensive, particularly up front. Some cats are too ill for thyroid surgery from other illness, such as heart disease, and others don't have access to radiotherapy. If you miss a dose of Tapazole once in a while, it won't have a harmful impact on Fluffy. And she won't have to spend any time in the hospital for this option -- it's something you administer yourself.

Disadvantages to Tapazole

As mentioned above, Tapazole is a method to manage Fluffy's condition. It will not cure her hyperthyroidism, which means that she'll be on the medication the rest of her life. This also means that in the long run, it can become a pricey proposition, as she'll require regular blood testing to monitor her thyroid levels. Many cats will not tolerate being fed a pill or pills daily, often resulting in battles of wills with their owners. The transdermal gel, which is more expensive, can address this problem.

Side Effects of Tapazole

Side effects from Tapazole are relatively uncommon -- only about 15 percent of cats will experience side effects. Common side effects include lethargy, vomiting and loss of appetite. If any of these side effects occurs, medication is usually stopped until the symptoms subside. After the cat recovers, medication is restarted at a lower dose and then gradually increased to the initial dosage.

More serious side effects to Tapazole, including facial itching, may manifest. Anti-itch medication will give relief, as will discontinuing the medicine temporarily. The itching will likely reoccur whenever the medication is used. This problem occurs for less than 4 percent of cats using drug therapy for hyperthyroidism. Bone marrow changes occur in less than 4 percent of cats. Less than 2 percent of cats experience serious liver failure. In all cases, you'll need to use another method to treat the hyperthyroidism.

Always check with your veterinarian before changing your pet’s diet, medication, or physical activity routines. This information is not a substitute for a vet’s opinion.

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