The information provided here is meant to give you a general idea about each of the medication groups listed below. Only the most general side effects are included, so ask your healthcare provider if you need to take any special precautions. Use each of these medications only as recommended by your healthcare provider, and according to the instructions provided. If you have further questions about usage or side effects, contact your healthcare provider.

Antithyroid Medications

Antithyroid medications suppress thyroid activity. They are best suited for the treatment of Graves’ disease . The dose can be gradually reduced as the function of the thyroid decreases. It usually takes 6 to 8 weeks of treatment for the medications to take affect and lower thyroid hormone to a healthy level. Until the treatment takes effect, your doctor may prescribe a beta-blocker to slow down the heart rate and relieve the jitters, sweating, and anxiety. When the above symptoms subside, this beta-blocker can be tapered and discontinued.

About one month after you begin taking the antithyroid medication, you will be asked to see your doctor for a repeat of the thyroid function tests and a review of your signs and symptoms. The dose of your antithyroid medication may be changed based on the test results.

It usually takes 12 to 24 months of treatment before the thyroid produces a normal amount of thyroid hormone on its own. If hyperthyroidism goes into remission and your thyroid hormone levels return to normal, your doctor may decide to discontinue the medication. However, some patients relapse when the treatment stops; people who have had severe hyperthyroidism and large goiters are most likely to relapse, but it can happen to anyone. Therefore, all patients should see their doctor frequently the first year after stopping treatment and at least annually thereafter.

Prescription Medications

Antithyroid medications

  • Carbimazole
  • Propylthiouracil (PTU)
  • Methimazole (Tapazole)

Beta-blockers

  • Propranolol (Inderal)
  • Atenolol (Tenormin)
  • Metoprolol (Lopressor, Toprol)

Prescription Medications

Antithyroid Medications

The main antithyroid medications are the thionamides:

  • Carbimazole— Smoking can interfere with how your body uses this medication. If you smoke, talk to your doctor about how to quit .
  • Propylthiouracil (PTU)
  • Methimazole (Tapazole)

These drugs interfere with the thyroid gland’s ability to make hormones. These medications can be taken with meals or on an empty stomach. It is important to always take them at the same time in relation to meals, as food affects the amount of medication your body absorbs into the bloodstream. Therefore, always take your medication with meals or always take it on an empty stomach.

Possible side effects include:

  • Rash
  • Itchy skin
  • Fever
  • Achy joints

These side effects may go away spontaneously or after switching to another antithyroid medication.

Rare side effects include:

Since agranulocytosis is rare and is not predictable by doing blood tests, your physician must rely on your history to suspect when this serious complication has arisen. If, while you are on antithyroid medicine, you notice a high fever or serious infection, such as severe sore throat, notify your doctor immediately so that blood tests can be done to check for a low white count. The medicine must be stopped immediately.

Beta-blockers

Common names include:

  • Propranolol (Inderal)
  • Atenolol (Tenormin)
  • Metoprolol (Lopressor, Toprol)

Beta-blockers slow the heart rate. Typically, they are used to treat high blood pressure, but they are also helpful for reducing a rapid heartbeat, anxiety, or tremors, all of which can occur with hyperthyroidism. Do not stop taking a beta-blocker without checking with your doctor first; stopping abruptly can cause a dangerous increase in blood pressure.

Possible side effects include:

  • Bronchospasm/ asthma
  • Dizziness
  • Drowsiness
  • Loss of sex drive
  • Difficulty sleeping

Many of these side effects may go away spontaneously as your body gets used to the medication. Any breathing problems, however, can be serious and should be reported to your doctor. You may need a change of medication.

Special Considerations

Whenever you are taking a prescription medication, take the following precautions:

  • Take them as directed—not more, not less, not at a different time.
  • Do not stop taking them without consulting your healthcare provider.
  • Don’t share them with anyone else.
  • Know what effects and side effects to expect, and report them to your healthcare provider.
  • If you are taking more than one drug, even if it is over-the-counter, be sure to check with a physician or pharmacist about drug interactions.
  • Plan ahead for refills so you don’t run out.