Hyperthyroidism is a condition where the thyroid produces more thyroxine than is needed by the body. It is also known as an overactive thyroid or thyrotoxicosis.

The Drugs

• Carbimazole is normally prescribed in the first instance
• Propylthiouracil is an alternative and is often used if you are pregnant or breast-feeding
• Both drugs reduce the amount of thyroid hormone released into the blood
• They are suitable for children as well as for adults

Initial Treatment

• Initially a high dose of antithyroid drug
• Your doctor will review after about 3 - 8 weeks
• A blood test will be taken on review to check your thyroid levels
• The drug dose may be reduced if there is improvement

Are there any side effects?

• Sometimes minor ones, such as nausea, or a rash
• Very rarely, a dangerous side effect where the white blood cell count may be lowered. Watch out for signs of sore throat, unexplained fever or mouth ulcers and if you notice any of these make an urgent appointment to see your doctor and do not take another tablet until it is safe to do so

How long will I need treatment?

This will normally depend on the cause of your hyperthoridism and other factors such as age.

• You may be able to stop treatment within 12-18 months if your thyroid levels are within the normal range or...
• You may be prescribed anti-thyroid drugs for just a few weeks to bring your thyroid levels within the normal range and then treated with radioactive iodine
• Some elderly patients may be prescribed anti-thyroid drugs for life
• While you are taking anti-thyroid drugs the dose may need adjusting
• Blood tests may be carried out every 2-6 months to check your thyroid levels
• You will need further blood tests to check your thyroid levels if your symptoms return

What if the hyperthyroidism returns?

Treatment options are:

• Re-start the anti-thyroid drugs
• Surgery to remove all or part of the thyroid gland
• Radioactive iodine to destroy some of the thyroid tissue

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