What medications do typical adult patients with hyperthyroidism take?

Medications for Hyperthyroidism

Primary Treatment Options

Hyperthyroid patients typically take antithyroid drugs—either methimazole or propylthiouracil—to block excessive thyroid hormone synthesis, with methimazole being the preferred first-line agent in most cases. 1, 2, 3

Methimazole (Preferred Agent)

• Initial dosing: 15 mg daily for mild hyperthyroidism, 30-40 mg daily for moderate disease, and 60 mg daily for severe hyperthyroidism, divided into 3 doses at 8-hour intervals 1
• Maintenance dosing: 5-15 mg daily once control is achieved 1
• Methimazole is the drug of choice due to its longer half-life, once-daily dosing capability, and lower incidence of severe side effects compared to propylthiouracil 4
• Single daily dosing is effective in most patients, with euthyroid state typically achieved in approximately 16-17 weeks 5

Propylthiouracil (Alternative Agent)

• Initial dosing: 300 mg daily in divided doses; may increase to 400 mg daily for severe hyperthyroidism or very large goiters, with occasional patients requiring 600-900 mg daily 2
• Maintenance dosing: 100-150 mg daily 2
• Generally not recommended as first-line except in specific situations: first trimester of pregnancy, thyroid storm, or patients with severe reactions to methimazole 2, 3
• Propylthiouracil carries higher risk of severe hepatotoxicity, particularly at doses of 300 mg/day or higher 2

Treatment Duration and Strategy

• Antithyroid drugs are typically prescribed for 12-18 months with the goal of inducing long-term remission in Graves' disease 6, 7
• Recurrence after standard 12-18 month treatment occurs in approximately 50% of patients 7
• Long-term treatment (5-10 years) is associated with fewer recurrences (15%) compared to short-term treatment 7
• Antithyroid drugs are also used short-term to render patients euthyroid before definitive therapy with radioiodine or thyroidectomy 6

Adjunctive Medications

Beta-Blockers

• Used as second-line agents to control hyperthyroid symptoms (tachycardia, tremor, anxiety) while awaiting antithyroid drug effect 4

Corticosteroids

• Reserved for severe cases of destructive thyrotoxicosis (subacute thyroiditis) 7
• May be used as prophylaxis when radioiodine is administered to patients with Graves' ophthalmopathy 6

Other Second-Line Agents

• Potassium perchlorate, iodine, and lithium carbonate are rarely used alternatives 4

Disease-Specific Considerations

Graves' Disease (70% of hyperthyroidism cases)

• Antithyroid drugs are the preferred initial treatment 7
• Risk factors for recurrence include: age <40 years, FT4 ≥40 pmol/L, TSH-binding inhibitory immunoglobulins >6 U/L, and goiter size ≥WHO grade 2 7

Toxic Nodular Goiter (16% of cases)

• Antithyroid drugs will not cure this condition—they only provide temporary control 6
• Radioiodine is the treatment of choice for definitive management 6

Critical Safety Considerations

• Pediatric use: Propylthiouracil is generally not recommended in children except when alternative therapies are inappropriate; methimazole is preferred 2
• Pregnancy: Propylthiouracil is preferred in the first trimester due to lower risk of congenital anomalies 2
• Hepatotoxicity monitoring: Both drugs require monitoring, but propylthiouracil carries significantly higher risk of severe liver injury 2
• Most patients with hyperthyroidism will eventually require definitive treatment with radioiodine ablation (most common in the United States) or thyroidectomy, as antithyroid drugs alone rarely provide permanent cure 3, 6