Post-Radioiodine Graves’ Management: The PRAGMA Study

Petros Perros is a Consultant Endocrinologist at Newcastle Hospitals, and Honorary Senior Lecturer at Newcastle University. He is the Project Lead for the PRAGMA Study, a Society for Endocrinology research project which compares the incidence of dysthyroidism in post-radioiodine patients treated with difference management strategies.

Petros will be presenting the PRAGMA study’s latest findings next week in Brighton, which is hosting this year’s SfE BES conference. Ahead of the event, we asked him to write about the project and why it’s such an important Society project.

For more information, be sure to check out Petros’ talk at 16.45 on Tuesday 8 November in Syndicate One. Our Scientific Programme has more details.

Project Background

Grave’s Disease, an autoimmune condition, is the most common cause of hyperthyroidism. Radioiodine (RI) is an effective, safe and cheap treatment for hyperthyroidism, though it results in most patients with RI-treated Graves’ disease requiring life-long thyroid hormone replacement.

Ideally the transition from hyperthyroidism to a stable thyroid status (through thyroid hormone replacement) should be rapid and smooth. However, in practice fluctuations in thyroid status in the first year after RI are not uncommon.

In an attempt to achieve and maintain euthyroidism (in which the thyroid gland is functioning normally) after RI, endocrinologists employ different strategies. These will eventually include the introduction of levothyroxine, a synthetic thyroid hormone chemically identical to thyroxine. The two most typical treatment strategies are:

  • The use of anti-thyroid drugs for a period of time after RI. These are used either alone or in combination with levothyroxine – with levothyroxine is known as the “block and replace” strategy
  • Watchful monitoring and introduction of levothyroxine when required

This variation in management in response to fluctuations in thyroid status following RI was the inspiration for the PRAGMA Study. We set out to determine the extent of thyroid instability after RI, and to explore whether different strategies of management are associated with different degrees of thyroid instability.

The study was funded by the Clinical Endocrinology Trust and was included in the NIHR portfolio.

What has been achieved so far?

Thirty-four hospitals in the UK have recruited 812 patients over 2 years. One of the most striking findings was that a very large proportion of patients – 67.2% – had at least one episode of hypothyroidism within the first year after RI, and 36% had an episode of hyperthyroidism. Patients treated with the “block and replace” regimen after RI were least likely to experience hypothyroidism and gain weight, though hypothyroidism was still experienced in 26% of cases.

What next?

We continue to collect data in the management of this condition. Additional interventions need to be identified and implemented to improve outcomes for patients with Graves’ disease treated with RI, and this study provides us with great possibility.

The level of engagement of colleagues with the PRAGMA Study proves that large scale studies addressing common, simple, clinically relevant questions can be conducted with ease and minimal cost. It is a great asset to the field of clinical endocrinology research.

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