What Is the First-Line Treatment for Graves' Disease?
Graves' disease is a leading cause of hyperthyroidism. First-line management centres on restoring biochemical euthyroidism using antithyroid drug therapy, with careful monitoring of thyroid function throughout.
Treatment Approach
Antithyroid drug therapy is the foundation of first-line treatment, with methimazole (MMI) as the preferred agent in most patients — titrated according to thyroid function at initiation and adjusted as the patient responds. The full dosing strategy and sequencing are detailed in the complete protocol.
Clinical Goals
The target is achievement of biochemical euthyroidism: normalization of serum free T4 and total or free T3. Serum TSH may remain suppressed for months after starting therapy. Thyroid function is reassessed at regular intervals to guide dose adjustments.
References
DOI: 10.1016/j.ecl.2021.12.004.
- Methimazole (MMI) should be used in patients who choose ATD therapy for GD, except (a) during the first trimester of pregnancy when propylthiouracil (PTU) is preferred, (b) in the management of thyroid storm, and (c) in patients with minor adverse reactions to MMI who refuse radioactive iodine (RAI) therapy or surgery.
- Current practice guidelines suggest an initial MMI dosing of 5–10 mg daily if free T4 is 1–1.5 times the upper limit of normal; 10–20 mg daily if free T4 is 1.5–2 times the upper limit of normal; and 30–40 mg daily for free T4 2–3 times the upper limit of normal.
- MMI can be given once-a-day compared to PTU which has a shorter duration of action and is usually administered as 50–150 mg 3 times daily.
- Once the patient is biochemically euthyroid, gradual lowering of the MMI dose is advised, with repeated laboratory testing in 4–6 weeks.
- Serum TSH, free T4 and total or free T3 should be obtained initially at 2–4 week intervals after starting ATDs, and the dosage should be adjusted accordingly.