Take Drugs Safely
Before using an antithyroid drug, it's important to tell your doctor about pre-existing medical conditions and other medications you are taking. The potency of these other medications as well as that of the antithyroid drugs can be altered when the medications are taken together.
It's especially important to discuss anticoagulants, or blood thinners, such as warfarin (Coumadin); diabetes medications; and digoxin (Lanoxin), which is used to treat heart failure and abnormal heart rhythms. You should also tell your doctor about any vitamins and supplements you may be taking.
It's also important to tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. Methimazole cannot be taken during pregnancy because it can prevent the normal development of the baby's thyroid. Also, babies breast-fed by moms on methimazole are at risk for hypothyroidism. But because hyperthyroidism is harmful to a developing fetus, you will need to take low doses of PTU. You will also require frequent monitoring.
While the use of drugs is generally discouraged during pregnancy, some health conditions — including thyroid disease — require treatment for the healthy development of the fetus. Always discuss any drugs and supplements you use with your doctor, including over-the-counter products.
What's Best for Each Condition?
Because there are such diverse options, it's important to have an understanding of the different treatments for the different types of hyperthyroidism. In general:
If Graves' disease is the cause of your condition, medication or RAI is usually the top choice for treatment, then surgery.
If you have toxic multinodular goiter, the best choice is RAI, followed by surgery, then medication.
If hot nodules are the cause of your hyperthyroidism, RAI is generally the best treatment, followed by surgery.
If you have thyroiditis, the best treatment is the passage of time, though you may need beta-blockers to tame your symptoms, and aspirin to reduce the inflammation.
Every patient starts on a dose that best fits her situation. The more severe your hyperthyroidism, the higher your dose will be. Once your thyroid function stabilizes, you may be placed on a maintenance dose to ensure healthy amounts of thyroid hormone. In general, if you are on PTU, you will need to take your pills more frequently than someone on methimazole would.
About four weeks after you start taking your antithyroid drug, your doctor should monitor your hormone levels. If they're still high, you may need to increase your dosage. However, if hormone levels have fallen significantly, you may be able to reduce the dose of your drug and prevent the onset of hypothyroidism. After these initial tests, you should be monitored regularly until your TSH levels are normal. Beyond that, you may still need to have your thyroid hormone levels checked to make sure the hyperthyroidism doesn't recur. Patients usually take antithyroid medications for up to two years, at which time they can taper off the dosage.