Guide to Radioactive Iodine Treatment for Hyperthyroidism

Radioactive iodine therapy is an effective treatment for hyperthyroidism, a condition where your thyroid gland produces too much thyroid hormone. During this treatment, you will receive a single dose of radioactive iodine, which is taken orally. The radioactive iodine is specifically absorbed by your thyroid gland, where it helps to reduce overactive thyroid cells and lower hormone production to normal levels.

This treatment has been safely used for over 60 years to manage hyperthyroidism. While the treatment itself is straightforward, it requires some special precautions before and after administration to ensure both your safety and the safety of others.

This guide provides essential instructions to help you prepare for and recover from your radioactive iodine treatment. Please read and follow these instructions carefully.

Before Your Treatment

Medication Instructions:

• If taking carbimazole/thiamazole: Stop 4 days before and 3 days after treatment
• If taking propylthiouracil (PTU): Stop 7 days before and 3 days after treatment
• Complete your prescribed course of prednisolone as directed

Dietary Restrictions (4 days before and 3 days after treatment):

• Avoid excessive iodine intake
• Do not consume:
  • Seafood (fish, sushi, shellfish, kelp, seaweed)
  • Iodine-containing vitamins or supplements
  • Dairy products (milk, chocolate, ice cream, cheese, yoghurt, butter)
  • Egg yolks or foods containing whole eggs
  • Soy products (sauce, milk, tofu)
• Limit salt intake
• Avoid topical iodine applications

On Treatment Day:

• No food or drink 2 hours before and after treatment (plain water allowed)

After Your Treatment

Immediate Care:

• Drink 2-3 litres of fluid daily for 3 days (unless otherwise advised)
• Avoid crowded places for 2 days

For the First 3 Days:

• Sit whilst urinating (including men)
• Flush toilet twice after use
• Avoid close contact with pregnant women and children under 12
• Use separate utensils and wash clothes separately
• Clean shared telephone mouthpieces after use

Extended Precautions:

• Sleep separately from adults and avoid intimacy for 1 week
• Sleep separately from pregnant women and children under 12 for 3 weeks
• Avoid prolonged public transport (over 2 hours) for 1 week
• Carry your discharge note when travelling (4 weeks)

Special Considerations

For Female Patients:

• Confirm you are not pregnant before treatment
• Avoid pregnancy for 6 months after treatment
• Stop breastfeeding until next pregnancy

For Male Patients:

• Avoid impregnating partner for 4 months after treatment

Travel Requirements:

• Request a medical memo if travelling overseas post-treatment
• Keep discharge note with you for 4 weeks when travelling

Need More Information?

Contact the department of Nuclear Medicine and Molecular Imaging for any questions or concerns about these instructions. Alternatively, you may download our information leaflets below:
RAI for Hyperthyroidism (Eng).pdf
RAI for Hyperthyroidism (Chi).pdf