The thyroid is an endocrine gland found in the neck. The thyroid produces thyroid hormones, which regulate metabolism processes in the body. An overactive thyroid produces too many thyroid hormones, which leads to a condition known as hyperthyroidism. People with hyperthyroidism experience symptoms such as nervousness, weight loss, increased heart rate and increased sensitivity to heat. At the time of publication, there were only three medications used to suppress thyroid function in people with hyperthyroidism.
Radioactive Iodine
Radioactive iodine is used to treat an overactive thyroid. It suppresses thyroid function by destroying part of the thyroid gland. Radioactive iodine is administered orally and absorbed by the thyroid gland, where it causes the gland to shrink. Radioactive iodine may cause the thyroid to stop producing all thyroid hormones, which may lead to a condition known as hypothyroidism. If you take radioactive iodine, you may also need to take synthetic thyroid hormones.
Methimazole
Methimazole, also known as Tapazole, is a drug that works by inhibiting the synthesis of thyroid hormones. Methimazole does not inactivate existing thyroid hormones that are stored in the thyroid or circulating in blood, according to Drugs.com. If you have a blood disorder, liver disease or a weak immune system, your dose may require adjustment. Methimazole lowers the body's ability to fight infections. Avoid receiving live vaccines while you are being treated with methimazole because you can develop serious infections.
Propylthiouracil
Propylthiouracil is in a class of medications known as anti-thyroid agents. It works by stopping the thyroid from making thyroid hormone. Propylthiouracil is reserved for people who cannot tolerate methimazole or for whom radioactive iodine therapy is not an appropriate treatment, according to Drugs.com. If you have a blood disorder or liver problems, a doctor may need to readjust the doses of your other medications before prescribing propylthiouracil. Propylthiouracil can lower the ability of the body to fight infections, so if you are taking it, avoid contact with people with infections.
Side Effects of Thyroid-suppression Medications
Common side effects of propylthiouracil and methimazole include dizziness, drowsiness, upset stomach, muscle pain, joint pain, hair loss, decreased sense of taste, nausea and vomiting, according to Drugs.com. Adverse effects of propylthiouracil and methimazole include yellowing of the skin, dark urine, clay-colored stool, fever and itching, unusual weakness, and easy skin bruising.
