Hyperthyroidism

Question 1

What is hyperthyroidism?

Answer 1

Also known as thyrotoxicosis, caused by over secretion of the thyroid hormones T3 and T4. Risk of developing increases with age. Long-term consequences include damage to sight, changes in facial appearance, CVD and osteoporosis.

Question 2

What are the 2 main causes of hyperthyroidism?

Answer 2

Graves’ disease and toxic multinodular goitre

Question 3

What is Graves’ disease?

Answer 3

accounts ofr 75% of all cases. Autoimmune disease where body’s immune system produced an antibody that mimics the effects of TSH which increase T4 and T4 secretion. Patients will develop an enlarged thyroid gland and may develop protrusion of the eyeballs (exophthalmos)

Question 4

What is toxic multinodular goitre?

Answer 4

A few nodules of the thyroid gland start to secrete excess T3 and T4. This type of hyperthyroidism does not affect the eyes.

Question 5

What are other causes of hyperthyroidism?

Answer 5

• amiodarone
• cancer of the thyroid gland
• pituitary tumour
• taking too much levothyroxine
• smoking
• often a genetic link

Question 6

What are some main symptoms of hyperthyroidism?

Answer 6

• nervousness, anxiety and irritability, palpitations
• talking quickly
• insomnia
• twitching or trembling
• fatigue, muscle weakness
• increased appetitie and weight loss due to increase metabolism, diarrhoea

Question 7

What are other symptoms of hyperthyroidism?

Answer 7

• sensitivity to heat, sweating
• persistent thirst
• itchiness
• loss of interest in sex
• goitre
• hot flushes
• a raised, itchy rash
• patchy hair loss or thinning
• eye problems, such as redness, dryness or vision problems

Question 8

What is the treatment for hyperthyroidism?

Answer 8

• drugs
• radioactive iodine
• surgery

Question 9

What drugs are used to treat an overactive thyroid and how do they achieve this?

Answer 9

Drugs called thionamides (main drugs used are carbimazole and propylthiouracil). Stop thyroid gland producing excessive amounts of thyroid hormones.

Question 10

How long does it take for antithyroid drugs to to work?

Answer 10

6-8 weeks

Question 11

What are the 2 regimes used after blood tests show that thyroid levels are under control?

Answer 11

titration and block and replace

Question 12

What is titration?

Answer 12

The dose of anti-thyroid drug is reduced, the aim being to keep the patient on the lowest dose of drug needed to keep thyroid function normal

Question 13

What is the ‘block and replace’ regime

Answer 13

Anti-thyroid drug taken until thyroid gland stops producing thyroid hormones; at this point patient starts taking levothyroxine to replace thyroid hormone.

Question 14

What are some side effects of antithyroid drugs?

Answer 14

• feeling sick
• headaches
• aching joints
• altered taste
• upset stomach
  most common side effect is generalised itchy redness. Less common side effect is bone marrow suppression.

Question 15

What link do betablockers have in regards to hyprthyroidism?

Answer 15

Beta blockers do not affect thyroid function but used alongside anti-thyroid drugs to manage symptoms of hyperthyroidism. Propranolol is usually used

Question 16

What is radioactive iodine treatment?

Answer 16

Is a type radiotherapy which causes damage to the DNA of thyroid cells, leading to their death and therefore reducing the amount of thyroid hormones produced. Patient given capsule (or drink) that contians iodine and a low dose of radiation. because it contains iodine, it is absorbed by the thyroid and the radiation destroys the thyroid gland. Can take weeks or months to feel full benefits and normally only a single treatment is needed.

Question 17

What are some precautions patients should take after radioactive iodine treatment?

Answer 17

• avoid prolonged close contact with children and pregnant women for a few dyas or weeks
• women should avoid getting pregnant for at least 6 months
• men should not father a child for at least 4 months