Endocrine Abstracts

Introduction: Faster decline in serum thyroid hormone levels in hyperthyroidism is seen adding cholestyramine at conventional treatment in some studies (1.2).

Design/methods: Retrospective controlled study. Follow-up: ±3 weeks.

Patients with hyperthyroidism: 17 treated with antithyroid drugs (mean dose 35 mg/day) combined with cholestyramine (mean dose 12 g/day).

Control group: 23 only treated with antithyroid drugs (mean dose 20 mg/day).

Patients with Quervain disease: 5 treated with cholestyramine (mean dose 12 g/day). Control group: 5 without therapy.

FT₄ and FT₃ values between groups at baseline and after follow-up period were compared. Statistical analysis: Student’s t-test.

Results: Patients with hyperthyroidism: cholestyramine vs control group showed decline: FT₄: 61 vs 20%, P<0.01 and FT₃: 72 vs 48%, P<0.02. Patients with severe hyperthyroidism were all treated with cholestyramine and higher doses of antithyroid drugs. Subgroup analysis in mild hyperthyroidism and equal dose of medication (5 versus control 6 patients) showed: FT₄: 48 vs 19%, P<0.05 and FT₃: 57 vs 25%, P<0.2. Patients with Quervain disease: cholestyramine versus control group showed: FT₄: 51 vs 41%, P<0.3 and FT₃: 54 vs 11%, P<0.05.

Discussion: Cholestyramine added in treatment of hyperthyroidism shows faster decline in thyroid hormone levels during the first weeks. In this study, the effect is less in mild hyperthyroidism, probably because of smaller increase in T₃-concentration in bile and faeces, but seems more pronounced in severe hyperthyroidism.

Conclusion: Cholestyramine is an option as adjunctive therapy especially in severe hyperthyroidism, obtaining faster decline in thyroid hormone levels.