International guidelines recommend high-dose corticosteroids and/or antithyroid drugs for the management of amiodarone-induced thyrotoxicosis (AIT), however, the evidence supporting these recommendations is limited. We evaluated real-world clinical practice relative to guideline recommendations and its association with clinical outcomes in patients with AIT.

We conducted a retrospective cohort study of all patients diagnosed with AIT between 2020 and 2024 at a tertiary hospital. Initial management was classified as guideline-defined therapeutic-dose medical therapy (prednisolone 30mg daily and/or carbimazole 45mg daily, or equivalent), subtherapeutic-dose medical therapy (prednisolone <30mg daily and/or carbimazole <45mg daily), or observation alone. The primary outcome was time to biochemical euthyroidism. Kaplan-Meier analysis with log-rank testing compared time to euthyroidism between therapeutic and subtherapeutic treatment groups. Patients managed with observation alone were excluded from the primary Kaplan-Meier analysis as follow-up data was incomplete due to discharge to primary care. Treatment trajectories and clinical outcomes were qualitatively described.

Twenty-eight patients were included: 9 (32.1%) received therapeutic management, 13 (46.4%) received subtherapeutic management, and 6 (21.4%) were managed with observation alone. Baseline demographic and clinical characteristics were similar between the therapeutic- and subtherapeutic-dose groups (all p >0.05). Median time to euthyroidism was 98 days in the therapeutic group and 59.5 days in the subtherapeutic group. Kaplan-Meier analysis demonstrated no significant difference in time to euthyroidism (log-rank χ²(1) = 0.58, p=0.45). 23.1% of patients initially prescribed subtherapeutic-dose therapy were subsequently escalated to therapeutic-dose treatment. 16.7% of patients initially managed with observation alone were later treated with pharmacotherapies.

Deviation from guideline-recommended initial dosing was common in this real-world cohort and was not associated with a statistically significant difference in time to euthyroidism. Study limitations include retrospective design, small sample size and potential residual confounding. Larger prospective studies are needed to determine whether lower-dose regimens are non-inferior to guideline-directed therapies whilst reducing treatment-related adverse effects.