From the Guidelines
Graves' disease should be treated with a thioamide, such as propylthiouracil or methimazole, to maintain FT4 or FTI in the high-normal range using the lowest possible dosage. The goal of treatment is to reduce thyroid hormone levels while minimizing side effects, such as agranulocytosis, hepatitis, vasculitis, and thrombocytopenia 1.
Treatment Options
- Thioamides, such as propylthiouracil or methimazole, are the primary treatment for hyperthyroidism in pregnancy, with no significant differences in mean FT4 or TSH levels in newborn cord-blood samples, and similar rates of fetal anomalies for both agents 1.
- Beta blockers, such as propranolol, can be used to reduce symptoms like rapid heartbeat and tremors until thioamide therapy reduces thyroid hormone levels 1.
Monitoring and Follow-up
- Measuring FT4 or FTI every two to four weeks can be helpful in adjusting the thioamide dosage 1.
- Regular monitoring of thyroid function is essential to prevent suppression of fetal and neonatal thyroid function, which can occur with thioamide therapy for Graves' disease, although it is usually transient and rarely requires treatment 1.
Important Considerations
- Agranulocytosis, a side effect of thioamides, usually presents with sore throat and fever, and requires immediate discontinuation of the thioamide and a complete blood cell count 1.
- Women treated with propylthiouracil or methimazole can breastfeed safely 1.
From the Research
Graves' Disease Overview
- Graves' disease is an autoimmune disorder that causes hyperthyroidism, characterized by an overproduction of thyroid hormones.
- Treatment options for Graves' disease include anti-thyroid drugs, radioactive iodine, and surgery.
Treatment with Anti-Thyroid Drugs
- A study published in the Endocrine Journal in 2003 2 investigated the use of minimum maintenance doses of anti-thyroid drugs to predict remission in Graves' disease.
- The study found that 81% of patients who received minimum maintenance therapy with anti-thyroid drugs for at least 6 months were able to maintain remission after discontinuation of the drugs.
- The study used methimazole (MMI) or propylthiouracil (PTU) as the anti-thyroid drugs, with initial doses of 30 mg/day of MMI or 300 mg/day of PTU, which were gradually decreased to a minimum maintenance dose.
Prediction of Remission
- The study found that the measurement of TSH-binding inhibitory immunoglobulin (TBII) or thyroid-stimulating antibodies (TSAb) gave little additional information for predicting remission 2.
- However, the study did find that patients with lower activities of TBII and TSAb at the time of drug cessation were more likely to remain in remission.
- The study suggests that minimum maintenance therapy to keep euthyroid for 6 months is a practical measure for predicting remission in Graves' disease 2.
Relapse Rates
- The study found that 11 patients (19%) relapsed into thyrotoxicosis after discontinuation of the drugs, while 46 patients (81%) remained in remission 2.
- The study also found that thyrotoxicosis relapsed in 5 (11%) of 47 TBII negative patients and 2 (8%) of 25 TSAb negative patients.