Because there are multiple disorders that affect the thyroid glands, not one thyroid medicine is capable of curing or controlling every thyroid problem. There are a few different types of thyroid medicine which can be prescribed for treatment; however, none of them are available over the counter. The type of thyroid medicine prescribed will depend on the disorder or disease that a patient is suffering from. Although thyroid disorders may be symptoms of underlying conditions or diseases, they manifest as hypothyroidism or hyperthyroidism.
It is important to understand how the thyroid gland works, before thyroid disorders and thyroid medicines can be understood. The thyroid gland is located in the neck immediately below the larynx. It is responsible for producing hormones, triiodothyronine (T3) and thyroxine (T4). These hormones travel in the bloodstream and regulate how the human body stores and uses energy. Thyroid stimulating hormone (TSH) that is made by the pituitary gland stimulates the thyroid gland to produce T3 and T4.
Hypothyroidism occurs when an underactive thyroid gland does not produce enough thyroid hormone. Common symptoms of hypothyroidism are depression, fatigue, weight gain, always feeling cold, menstrual irregularities, constipation and dry skin and hair. Blood tests are capable of measuring all hormone levels and a test that shows high TSH and low T4 levels will indicate hypothyroidism, which is the most common of all thyroid disorders. Levothyroxine is the thyroid medicine that is used to treat hypothyroidism. It is a synthetic form of T4 that replaces what the thyroid gland is not producing.
Hyperthyroidism occurs when an overactive thyroid produces too much thyroid hormone. Common symptoms of hyperthyroidism are being hot, sweating, fast heart rate, muscle weakness, trembling hands, weight loss, diarrhea, anxiety, menstrual irregularities and infertility. Hyperthyroidism is revealed on a blood test when T3 and T4 levels are elevated and TSH levels are lower than normal.
Hyperthyroidism is usually controlled, but not cured, by anti-thyroid medications. The preferred thyroid medicine is methimazole. Women who are pregnant or lactating are prescribed propylthiouracil. Both of these drugs lower the amount of thyroid hormone produced by the thyroid gland.
Another treatment for hyperthyroidism is radioactive iodine treatment (RAI). RAI is administered orally via capsule. After the capsule breaks down in the digestive system, the iodine is absorbed by the thyroid gland and begins to cause some of the thyroid cells to stop functioning so they don’t produce hormones. Enough RAI is given to cause the thyroid to become underactive, which will require that levothyroxine must be taken for life.