Sodium ipodate in the preparation of Graves' hyperthyroid patients for thyroidectomy

Sodium ipodate (SI) is an oral cholecystographic agent that also affects thyroid hormone metabolism. It inhibits the peripheral T4 to T3 conversion and the thyroidal hormone release. We investigated the safety and efficacy of SI (500 mg daily during 5 days) in the preparation for subtotal thyroidectomy of 7 Graves' hyperthyroid patients in whom treatment with thionamides was unsuccessful due to allergy or noncompliance. Plasma T3 levels (mean +/- SD) decreased from 4.90 +/- 1.80 nmol/l on day 0 to 1.70 +/- 0.30 nmol/l on day 4 of treatment. Thyroidectomy performed on day 5 of treatment was uneventful. In comparison with 14 Graves' hyperthyroid patients who underwent thyroidectomy during the same period after conventional preparation with thionamides and potassium iodide, the therapeutic outcome 1 year postoperatively was similar in both groups. However, in the mildly hypothyroid patients prepared with SI, the plasma thyroid-stimulating hormone level was transiently higher 3 and 6 months postoperatively. It is concluded (1) that SI is a safe and efficacious drug in the preparation of Graves' hyperthyroid patients for thyroidectomy; (2) the therapeutic outcome 12 months postoperatively is similar in SI and in conventionally prepared Graves' hyperthyroid patients, and (3) postoperative mild or subclinical hypothyroidism is more pronounced in SI than in conventionally prepared patients.