Compounded Methimazole (Tapazole)
This medication is used in both humans and animals. It is important to note that the strength given to humans is often not suitable for animals. Most often prescriptions for animals require a compounded medication. Methimazole is given to lower thyroid hormone levels. Methimazole does not cure an overactive thyroid but does help to control the disease. This medication is often given lifelong for this condition. Methimazole is also given to dogs for kidney protection during chemotherapy. This medication takes several doses before any effect can be seen. It often takes several weeks of consistent dosing until the medications full effects can be seen. However, you may not see the effects of this medication outwardly. Because the true benefits of the medication to your animal’s health are often not seen outwardly, your veterinarian will require additional tests in order to monitor the effectiveness. Methimazole does require a prescription from your veterinarian in order to be dispensed. You and your veterinarian should discuss if this is the best option for your pet.
Methimazole may be administered orally or by transdermal route in the inner ear flap and can be compounded into the desired strength and flavor that best suits your pet. We compound this medication into suspensions, capsules, and transdermal cream. Methimazole may be given with food or on an empty stomach. If your animal vomits after receiving the medication on an empty stomach, you may give with a small amount of food or treat. This medication is considered a hazardous drug and may be harmful to individuals that touch the medication if it is not prescribed to them. Therefore, gloves should be worn while administering the medication to your animal. In addition, pregnant women should use caution when handling this medication as it may contribute to a higher risk for birth defects. Methimazole should be given as instructed on your prescription. If you miss a dose do not double up on the medication. Wait until the next dose is due and follow the normal dosing schedule as directed.
The most common side effects in animals while taking methimazole are diarrhea, vomiting, and loss of appetite. Methimazole is well tolerated and side effects are most common in the first 3 months of use. Overdoses of this medication can be serious. If you suspect an overdose, contact your veterinarian or poison control.