What is the management of a patient with a history of toxic nodular goitre (TNG) who is non-adherent to anti-thyroid medication and presents with palpitations and tachycardia, and has a low Thyroid-Stimulating Hormone (TSH) level?

Management of Toxic Nodular Goitre with Poor Medication Adherence

Radioiodine therapy (RAI) is the most appropriate management for this patient with toxic nodular goitre who has demonstrated poor adherence to antithyroid medications and presents with symptoms of hyperthyroidism and a suppressed TSH. 1, 2

Assessment of Current Status

The patient presents with:

• History of toxic nodular goitre
• Poor adherence to antithyroid drugs
• Active symptoms: palpitations and tachycardia
• Suppressed TSH (0.2), indicating persistent hyperthyroidism

Treatment Options Analysis

Antithyroid Drugs (Option C)

• While antithyroid drugs can effectively control hyperthyroidism, this patient has already demonstrated poor adherence
• Long-term success rates with antithyroid drugs in toxic nodular goitre are lower than with definitive treatments
• The patient's current symptoms indicate treatment failure with this approach 2
• Continuing the same approach that has already failed is not recommended

Surgical Options (Options A & B)

• Total or near-total thyroidectomy provides definitive treatment for toxic nodular goitre
• Surgery has a high cure rate (93% reported in studies) 2
• However, surgery carries risks of complications including recurrent laryngeal nerve damage and hypoparathyroidism
• Surgery requires good perioperative control of hyperthyroidism, which may be difficult in a non-adherent patient

Radioiodine Therapy (Option D)

• RAI offers definitive treatment with a high success rate (89% with one treatment) 2
• Particularly suitable for patients with poor medication adherence as it requires only a single administration
• Avoids surgical risks while providing permanent resolution of hyperthyroidism
• Can be administered as an outpatient procedure with minimal preparation

Management Algorithm

1. First-line treatment: Radioiodine therapy

   • Provides definitive treatment for toxic nodular goitre
   • Eliminates the need for daily medication adherence
   • High success rate with a single treatment (89%) 2

2. Pre-RAI considerations:

   • Control acute symptoms with beta-blockers (preferably with alpha-blocking capability) 1
   • Withdraw antithyroid drugs for at least 2 weeks prior to RAI to improve treatment efficacy 3
   • Perform radioiodine uptake measurement to confirm diagnosis and determine appropriate dosing 4

3. Post-RAI follow-up:

   • Monitor thyroid function tests every 4-6 weeks initially
   • Be aware that hypothyroidism is a common outcome (58% of patients) 2
   • Initiate levothyroxine therapy if hypothyroidism develops

Important Considerations

• Approximately 5% of patients may require multiple RAI treatments to achieve cure 2
• Long-term quality of life impairments may persist even after successful treatment of hyperthyroidism 2
• The patient should be informed that RAI often leads to hypothyroidism requiring lifelong thyroid hormone replacement
• Beta-blockers should be used to control symptoms until RAI takes effect (typically 1-3 months)

Conclusion

For a patient with toxic nodular goitre who has demonstrated poor adherence to antithyroid medications and presents with active hyperthyroid symptoms, radioiodine therapy (Option D) is the most appropriate management strategy. This approach provides definitive treatment while eliminating the need for daily medication adherence, which has already proven problematic for this patient.