The medications given to treat thyroid disorders depend upon whether the patient is hyperthyroid or hypothyroid. Hyperthyroidism refers to the body making excessive amounts of thyroid hormone. Treatments are aimed at controlling symptoms and lowering the blood concentration of thyroid hormone. Hypothyroidism refers to the body not making enough thyroid hormone. Replacement of thyroid hormone is the mainstay of treatment for hypothyroidism.
Levothyroxine
Levothyroxine is thyroid hormone replacement. It is the gold standard treatment for hypothyroidism. Levothyroxine is converted to the more active thyroid hormone in the body. The medication is taken every day, typically in the morning along with water. There are medications and other foods and drugs that can change the intestinal absorption of the medication. Calcium, iron, soy, and antacids can all reduce the absorption of levothyroxine in the intestines. A clinician will monitor patients and adjust medication levels based on symptoms and blood hormone levels.
Propranolol
Propranolol is a non-selective beta blocker that does not correct the underlying hyperactive thyroid disorder, however it helps decrease the symptoms of hyperthyroidism. These symptoms include tachycardia or elevated heart rate, tremor, diaphoresis or sweating, and anxiety. Propranolol can be used for symptom relief while the patient is awaiting definitive treatment for hyperthyroidism.
Methimazole
Methimazole is a medication used to treat conditions where there are elevated levels of thyroid hormone in the body. The advantages over propylthioruracil are less frequent dosing and less total pills required to achieve therapeutic levels. The side effects of methimazole tend to be less severe than for propylthioruracil in regards to liver disease. Other complications include serum sickness, cholestatic jaundice, loss of taste, hair loss, nephritic syndrome, and hypoglycemia or low blood sugar levels.
Propylthiouracil
Propylthioturacil (PTU) is a medication used to treat elevated thyroid levels. It is the drug of choice in pregnancy and breast-feeding due to less newborn side effects. In most other cases of elevated thyroid hormone levels, methimazole is used for treatment instead of propylthiouracil.
Iodinated Contrast Agents
Iodinated contrast agents like iopanoic acid and ipodate sodium are used for temporary treatment of elevated thyroid levels. These drugs stop the conversion of thyroid hormone into the more active form. Treatment with iodinated contrast agents tends to be very helpful for patients who are very symptomatic from their overactive thyroid.
Radioactive Iodine (I-131)
Radioactive iodine (RAI) works by destroying the overactive thyroid and any thyroid tissue that has not been removed during surgery according to the American Cancer Society. After treatment with radioactive iodine, some patients have to remain in the hospital for a few days, while others can go home right after treatment. There is the risk of radiation exposure to others after treatment with RAI. Some patients stay in an isolation room after surgery, while others go home with instructions on how to protect others from radiation. Avoiding contact with pregnant women and children is advised post RAI treatment. A full list of precautions will be given to a patient by the endocrinologist supervising the RAI treatment.
References
- "American Family Physician": Subclinical Thyroid Disease
- "Lippincott's Illustrated Reviews: Pharmacology (3rd edition)"; Dr Richard Howland, Dr Mary Mycek; 2006.
- American Cancer Society: Radioactive Iodine Therapy
- Endocrinologist: Radioactive Iodine
