From the Guidelines
Free T3 syndrome is not directly mentioned in the provided evidence, but based on the context of thyrotoxicosis, it can be inferred that elevated levels of free T3 may occur secondary to thyroiditis or Graves’ disease, particularly in patients taking immune checkpoint inhibitors 1. The provided evidence discusses thyrotoxicosis, which may present with high free T4 or total T3 levels, and low or normal TSH, but it does not specifically address Free T3 syndrome. However, it is essential to consider the clinical context and potential causes of elevated free T3 levels. Some key points to consider in the management of patients with potential Free T3 syndrome include:
- Careful monitoring of thyroid hormone levels, as thyroiditis is a self-limiting process that may lead to permanent hypothyroidism after an average of 1 month after the thyrotoxic phase 1
- Conservative management during the thyrotoxic phase, with non-selective beta blockers, preferably with alpha receptor-blocking capacity, may be needed in symptomatic patients 1
- Investigation of the underlying cause, as certain medications or conditions may contribute to the development of Free T3 syndrome
- Regular follow-up with an endocrinologist, with thyroid function tests every 2-3 weeks, to monitor changes and initiate thyroid hormone replacement at the time of hypothyroidism diagnosis 1