What is the dose of Thyrozol (Propylthiouracil) in Graves' disease (Basedow's disease)?

From the Guidelines

Thyrozol dosing for Basedow's disease should start at 10-30 mg daily, divided into 2-3 doses, with the goal of maintaining FT4 or FTI in the high-normal range using the lowest possible dosage. This approach is supported by the American College of Obstetricians and Gynecologists (ACOG) practice bulletin on thyroid disease in pregnancy, which recommends using thioamides, such as propylthiouracil or methimazole, to treat hyperthyroidism in pregnant women 1. The initial dose can be adjusted based on disease severity, with mild cases requiring 10-15 mg daily and moderate to severe cases requiring 20-30 mg daily. It is essential to monitor thyroid hormone levels every 2-4 weeks to adjust the dosage as needed. Potential side effects, such as agranulocytosis, hepatitis, vasculitis, and thrombocytopenia, should be closely monitored, and the medication should be discontinued if any of these symptoms develop 1.

• Key considerations for Thyrozol dosing include:
  • Initial dose: 10-30 mg daily, divided into 2-3 doses
  • Disease severity: mild cases may require 10-15 mg daily, while moderate to severe cases may require 20-30 mg daily
  • Monitoring: thyroid hormone levels should be checked every 2-4 weeks to adjust the dosage as needed
  • Side effects: agranulocytosis, hepatitis, vasculitis, and thrombocytopenia should be closely monitored
  • Treatment duration: typically 12-18 months, after which patients can attempt discontinuation with close monitoring for relapse.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Propylthiouracil is administered orally. The total daily dosage is usually given in 3 equal doses at approximately 8-hour intervals. Adults The initial dose is 300 mg daily. In patients with severe hyperthyroidism, very large goiters, or both, the initial dose may be increased to 400 mg daily; an occasional patient will require 600 to 900 mg daily initially The usual maintenance dose is 100 to 150 mg daily.

The dose of Thyrozol (Propylthiouracil) in Basedow (Graves' disease) is:

• Initial dose: 300 mg daily, which can be increased to 400 mg daily in patients with severe hyperthyroidism.
• Maintenance dose: 100 to 150 mg daily. 2

From the Research

Thyrozol Dose in Basedow

• The optimal dose of methimazole (Thyrozol) for the treatment of Graves' disease, also known as Basedow's disease, is still a topic of debate among researchers.
• A study published in 2015 3 found that high doses of methimazole (60-80 mg) followed by a rapid dose reduction did not influence the course of the disease or the remission rates.
• Another study from 1986 4 suggested that a single daily dose of 15 mg of methimazole is effective in most patients with Graves' hyperthyroidism and causes fewer adverse effects.
• A more recent study from 2007 5 compared the efficacy and adverse reactions of methimazole and propylthiouracil in patients with hyperthyroidism caused by Graves' disease, and found that methimazole 30 mg/d was more effective in normalizing serum free T4 levels, especially in patients with severe hyperthyroidism.
• The study also found that methimazole 15 mg/d is suitable for mild and moderate Graves' disease, while methimazole 30 mg/d is advisable for severe cases.
• A study from 2003 6 found that a practical therapy with minimum maintenance dose of anti-thyroid drugs, such as methimazole 5 mg every other day, can predict remission in Graves' disease with an accuracy of 81%.
• It is worth noting that the dosage of methimazole may need to be adjusted based on individual patient factors, such as the severity of the disease and the presence of adverse effects.

Dosage Considerations

• The initial dose of methimazole can range from 15 mg to 30 mg per day, depending on the severity of the disease and the patient's response to treatment.
• The dose can be adjusted based on regular monitoring of thyroid hormone levels and clinical symptoms.
• Patients with severe hyperthyroidism may require higher doses of methimazole, while those with mild or moderate disease may be able to achieve remission with lower doses.
• The use of propylthiouracil is not recommended for initial use due to the higher risk of adverse effects, such as hepatotoxicity 5.