Clinical Trial: Antithyroid Drugs During Radioiodine Therapy
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: The Influence of Continuous Treatment With Antithyroid Drugs on the Effect of Radioiodine in Patients With Hyperthyroidism
Brief Summary:
Background: The use of radioactive iodine (131I) therapy as the definite cure of hyperthyroidism is widespread. According to a survey on the management of Graves’ disease, thirty per cent of physicians prefer to render their patients euthyroid by antithyroid drugs (ATD) prior to 131I therapy. This strategy is presumably chosen to avoid 131I induced ‘thyroid storm’, which, however, is rarely encountered. Several studies have consistently shown that patients who are treated with ATD prior to 131I therapy have an increased risk of treatment failure. Mostly, patients with Graves’ disease have been studied, while other studies were addressed also toxic nodular goiter. Thus, it is generally accepted that ATD have ‘radioprotective’ properties, although this view is almost exclusively based on retrospective data and is still under debate (13). Indeed, this dogma was recently challenged by two randomized trials in Graves’ disease, none of which showed such an adverse effect of methimazole pretreatment. It cannot be excluded that the earlier results may have been under influence of selection bias, a source of error almost unavoidable in retrospective studies. Whether ATD is radioprotective also when used in the post 131I period has also been debated. In the early period 131I therapy following a transient rise in the thyroid hormones is seen which may give rise to discomfort in some patients. The continuous use of ATD during 131I therapy leads to more stable levels of the thyroid hormones. By resuming ATD following 131I therapy, euthyroidism can usually be maintained until the destructive effect of 131I ensues. Nevertheless, many physicians prefer not to resume ATD, probably due to reports supporting that such a strategy reduces the cure rate. Parallel to the issue of ATD pretreatment, the evidence is based on retrospective studies and the ideal set-up should be reconsidered. To underscore
Detailed Summary:
Sponsor: Odense University Hospital
Current Primary Outcome: Thyroid function after one year of follow-up
Original Primary Outcome: Same as current
Current Secondary Outcome:
- Thyroid radioiodine 131I uptake
- Thyroid volume after one year of follow-up
Original Secondary Outcome: Same as current
Information By: Odense University Hospital
Dates:
Date Received: September 6, 2005
Date Started: January 2003
Date Completion: December 2004
Last Updated: February 2, 2006
Last Verified: September 2005
