[Side effects of antithyroid drugs]

Area of Science:

• Endocrinology
• Immunology
• Pharmacology

Background:

• Graves' disease is an autoimmune disorder requiring antithyroid drug treatment.
• Side effects of antithyroid drugs can impact patient compliance and treatment outcomes.
• Previous reports suggest varying incidences of antithyroid drug side effects.

Purpose of the Study:

• To investigate the incidence of side effects associated with methimazole and propylthiouracil in Graves' disease patients.
• To identify factors, particularly immunological markers, related to the onset of antithyroid drug side effects.
• To explore the potential role of allergic mechanisms in adverse drug reactions.

Main Methods:

• Clinical and laboratory findings were analyzed in 71 untreated Graves' disease patients.
• Patients were treated with either methimazole or propylthiouracil as the initial drug.
• Serum Ig-E levels and peripheral eosinophil counts were monitored before and during treatment.

Main Results:

• The overall incidence of side effects was 28.2%, with higher rates for propylthiouracil (46.7%) than methimazole (23.2%).
• Side effects typically occurred within 1.5 months and were often managed by switching medications, though some patients experienced recurrent side effects.
• Significantly elevated serum Ig-E and peripheral eosinophils were observed at the onset of side effects, suggesting an allergic basis.

Conclusions:

• The incidence of antithyroid drug side effects in this cohort was higher than previously reported.
• Allergic mechanisms, indicated by elevated Ig-E and eosinophils, appear to be involved in the onset of these side effects.
• Immunological disturbances inherent to Graves' disease may contribute to the development of antithyroid drug adverse reactions.