FOLLOW UP
After Initiating Antithyroid Drugs (ATDs: Methimazole, PTU)
A. Frequency of Monitoring
Check thyroid function tests (TFTs) every 4–6 weeks initially.
Reduce ATD dose once thyroid hormone levels fall; failure to reduce
leads to iatrogenic hypothyroidism.
B. Why dose reduction matters
Hypothyroidism → fatigue, weight gain
In Graves disease, hypothyroidism can worsen ophthalmopathy
(anecdotal but clinically recognized).
C. Long-term ATD therapy
Non-Graves hyperthyroidism (toxic multinodular goiter / toxic
adenoma):
→ Rarely remit → ATDs typically not curative.
→ If used long-term, test TFTs every 3 months in the first year.
D. In Graves disease
Stop or taper ATDs after 12–18 months to check for remission.
Remission definition: Normal TSH off therapy.
Relapses common → 50% within one year.
20% eventually become hypothyroid due to autoimmune
destruction.
E. What next after stabilization?
Once euthyroid, consider definitive therapy:
o Radioactive iodine
o Surgery
2. After Radioactive Iodine (¹³¹I) Therapy
A. Expected course
After Initiating Antithyroid Drugs (ATDs: Methimazole, PTU)
A. Frequency of Monitoring
Check thyroid function tests (TFTs) every 4–6 weeks initially.
Reduce ATD dose once thyroid hormone levels fall; failure to reduce
leads to iatrogenic hypothyroidism.
B. Why dose reduction matters
Hypothyroidism → fatigue, weight gain
In Graves disease, hypothyroidism can worsen ophthalmopathy
(anecdotal but clinically recognized).
C. Long-term ATD therapy
Non-Graves hyperthyroidism (toxic multinodular goiter / toxic
adenoma):
→ Rarely remit → ATDs typically not curative.
→ If used long-term, test TFTs every 3 months in the first year.
D. In Graves disease
Stop or taper ATDs after 12–18 months to check for remission.
Remission definition: Normal TSH off therapy.
Relapses common → 50% within one year.
20% eventually become hypothyroid due to autoimmune
destruction.
E. What next after stabilization?
Once euthyroid, consider definitive therapy:
o Radioactive iodine
o Surgery
2. After Radioactive Iodine (¹³¹I) Therapy
A. Expected course
