Table 1.

Summary of practices for physicians and patients, with regard to switching levothyroxine formulations, that were proposed in international/national guidelines/statements [3, 13, 20, 21]

For physicians

Patients should be maintained on the same brand name of levothyroxine product

If the brand of levothyroxine medication is changed from one brand to another brand, from a brand to a generic product or from a generic product to another generic product:

Patients should be re-evaluated and retested by measuring serum TSH in 6 weeks;

The drug should be retitrated as needed

For patients

Use the same brand of thyroid medication throughout your treatment

Thyroid disease often requires lifelong therapy and is best managed with consistent and precise treatment with the same brand of thyroid hormone

Your doctor may change your dose of thyroid hormone, but the brand of your thyroid hormone medication should always stay the same

When you go to the pharmacy, do not change the brand of your thyroid medication without checking with your doctor

You should not change your dose from one brand of thyroid medication to another, from your brand of thyroid medication to a generic product, or from one generic product to another without first checking with your doctor

If your doctor changes the type of thyroid medication you are taking, you will need to have repeat blood tests and visits to your doctor to make sure that you are on the correct dose. Your dose may need to be readjusted if your thyroid medication is changed