Treatment of Toxic Goiter in Pediatric Patients
Antithyroid drugs (ATDs), specifically methimazole, should be the first-line treatment for toxic goiter in pediatric patients, with surgery reserved for specific indications and radioactive iodine generally avoided in young children.
First-Line Treatment: Antithyroid Drugs
- Methimazole is the only antithyroid drug recommended for pediatric patients with toxic goiter/Graves' disease 1, 2
- Propylthiouracil (PTU) should NEVER be used as first-line therapy in children due to unacceptable risk of severe liver injury 3, 1
- Typical treatment duration with methimazole is 12-24 months, with remission occurring in only a minority of pediatric patients 1, 2
- Lower doses of methimazole may help minimize side effects while maintaining efficacy 2
- For mild allergic reactions to methimazole, concurrent antihistamine therapy can be considered to allow continued treatment 4
Monitoring During Antithyroid Drug Therapy
- Regular monitoring of thyroid function (TSH, free T4) is essential to maintain euthyroid state 3
- Thyroid function should be checked every 2-3 weeks initially, then periodically during treatment 5, 6
- Monitor for symptoms of agranulocytosis (fever, sore throat), which typically occurs within first 3 months of therapy 3
- Beta-blockers (e.g., atenolol or propranolol) can be used for symptomatic relief of adrenergic symptoms during the thyrotoxic phase 7, 5
Second-Line Treatment Options
Surgery (Thyroidectomy)
Surgery is indicated for pediatric patients with toxic goiter in the following situations:
- Large goiter causing compressive symptoms 2
- Confirmed or suspected thyroid malignancy 2
- Patients unable to use antithyroid drugs due to serious adverse effects 1, 2
- Failure to achieve remission after 1-2 years of antithyroid drug therapy 1
When surgery is performed:
- Near-total or total thyroidectomy is the recommended procedure 1, 2
- Surgery should be performed by an experienced thyroid surgeon as complications are considerably higher in children than adults 2
- Postoperative levothyroxine is indicated, but TSH suppression is not appropriate 8
Radioactive Iodine (RAI)
- Generally not recommended for children under 5 years of age 1, 2
- When used in older children/adolescents, administered doses should be >150 μCi/g of thyroid tissue 1, 2
- Will cause hypothyroidism in approximately 66% of patients, requiring lifelong thyroid hormone replacement 9
- Should be avoided in young children due to concerns about low-level whole body radiation exposure 2
Special Considerations
- Continuous methimazole treatment (beyond the standard 18-24 months) may be considered as an alternative to definitive therapy in some patients 9
- In a study of patients on continuous ATD therapy (mean 5.7 years), the mean methimazole dose was 4.6 mg daily with no serious complications 9
- For patients with persistent or relapsed hyperthyroidism who refuse ablative therapy, continuous methimazole treatment can maintain euthyroidism 9
Common Pitfalls and Caveats
- Never use propylthiouracil in pediatric patients due to risk of liver failure 3, 1
- Be vigilant for side effects of methimazole, including minor and major allergic reactions 2
- Recognize that most pediatric patients with toxic goiter will eventually need definitive therapy (surgery or radioactive iodine) as lasting remission with ATDs occurs in only a minority of patients 1, 2
- When choosing a treatment approach, thoroughly discuss the advantages and risks of each therapeutic option with the patient and family 1