From the Guidelines
Medications that can lower TSH levels include levothyroxine, liothyronine, high-dose glucocorticoids, dopamine agonists, and certain supplements containing biotin, with levothyroxine being the most commonly prescribed and typically started at 25-50 mcg daily for adults, as evidenced by 1 and 1. When considering medications to lower TSH levels, it's essential to prioritize those that have a direct impact on thyroid function.
- Levothyroxine is a synthetic thyroid hormone that works by increasing circulating thyroid hormone levels, which in turn suppresses TSH production by the pituitary gland, as noted in 1.
- Liothyronine is another synthetic thyroid hormone that works more rapidly than levothyroxine and is usually prescribed at 5-25 mcg daily, as seen in 1. Other medications that can inadvertently lower TSH levels include:
- High-dose glucocorticoids, such as prednisone, which can suppress TSH production, as mentioned in 1.
- Dopamine agonists, which can also lower TSH levels, although the exact mechanism is not fully understood, as discussed in 1.
- Certain supplements containing biotin, which can interfere with thyroid function tests and potentially lower TSH levels, as noted in 1. It's crucial to monitor thyroid function regularly and adjust medication dosages as needed to avoid overtreatment or undertreatment, which can lead to health problems, as emphasized in 1. Regular blood tests are essential to ensure that TSH levels are within the normal range, and medications should be taken consistently, usually in the morning on an empty stomach, 30-60 minutes before eating or taking other medications, as recommended in 1 and 1.
From the FDA Drug Label
Once clinical evidence of hyperthyroidism has resolved, the finding of an elevated serum TSH indicates that a lower maintenance dose of propylthiouracil should be employed.
- Medications that can lower TSH: Propylthiouracil can increase TSH levels when hyperthyroidism is resolved, indicating a need to adjust the dose.
- The medication propylthiouracil is used to treat hyperthyroidism and can affect TSH levels 2.
- Methimazole inhibits the synthesis of thyroid hormones, which can also affect TSH levels, although the label does not directly state its effect on TSH 3.
From the Research
Medications that can Lower TSH
- Methimazole (MMI) and propylthiouracil (PTU) are the main antithyroid drugs used for hyperthyroidism, which can lower TSH levels by inhibiting the synthesis of thyroid hormone 4
- Potassium perchlorate, beta blockers, iodine, lithium carbonate, and glucocorticoids are also used as second-choice drugs to treat hyperthyroidism, although their primary mechanism may not be directly related to lowering TSH 4
- Rituximab, a monoclonal antibody directed against human CD20, has been proposed as a biological therapy for cases of Graves' disease unresponsive to traditional drugs, which may indirectly affect TSH levels 4
- Antithyroid medications such as methimazole and propylthiouracil can be used to treat hyperthyroidism caused by overproduction of thyroid hormones, which can help lower TSH levels 5
- Long-term methimazole (LT-MMI) therapy has been shown to be effective in achieving and maintaining euthyroidism in patients with toxic multinodular goiter, resulting in lower TSH levels 6
- Elevated serum TSH concentrations during methimazole therapy have been associated with a favorable long-term prognosis in patients with Graves' disease, suggesting that hypothyroidism during antithyroid drug treatment can be a favorable indicator for long-term remission 7