Hyperthyroidism

Question 1

What is hyperthyroidism

Answer 1

Hyperthyroidism results from the excessive production and secretion of thyroid hormones leading to thyrotoxicosis (an excess of circulating thyroid hormones).

Low TSH and HIGH T4

Question 2

Symptoms of hyperthyroidism

Answer 2

• A goitre
• Hyperactivity
• Disturbed sleep
• Fatigue
• Palpitations
• Anxiety
• Heat intolerance
• Increased appetite

Question 3

What is the long term drug management of hyperthyroidism

Answer 3

Carbimazole – long term drug management (used in second trimester as propylthiouracil can cause hepatotoxicity - monitor

Propylthiouracil is alternative (drug of choice in first trimester as carbimazole can cause congenital defects)

Question 4

What do both carbimazole and propylthiouracil do?

Answer 4

Interfere with synthesis of thyroid hormones

Question 5

When is iodine used?

Answer 5

Used an an adjunct but avoid long term therapy

Question 6

What can carbimazole cause?

Answer 6

1. Neutropenia
2. Agranulocytosis
3. Risk of acute pancreatitis
4. Risk of congenital malformations
5. Symptoms of blood disorder such as sore throat, bleeding, purpura

Question 7

What can propylthiouracil cause?

Answer 7

1. Alopecia
2. Fever
3. Taste altered
4. Agranulocytosis
5. Encephalopathy

NOTE – patients should be monitored for signs of liver disorder such as dark urine, jaundice, itchy skin, fatigue, nausea.

Question 8

What is blocking replacement therapy?

Answer 8

A patient can be prescribed both drugs for hyperthyroidism and hypothyroidism simultaneously to bring the patient to a euthyroid (balanced) state.

Over treatment with antithyroid drugs may cause hypothyroidism

Avoid in pregnancy especially – can cause fetal goitre

Then use a combination of carbimazole and levothyroxine to bring thyroxine levels back to normal

Regime prevented in pregnancy

Question 9

Is the blocking replacement therapy used in pregnancy

Answer 9

No

Question 10

What is thyrotoxic crisis (thyroid storm)

Answer 10

Poorly controlled overactive thyroid which is life threatening

Medical emergency

• Radioactive iodine contraindicated in pregnancy

Question 11

What are some symptoms of thyrotoxic crisis

Answer 11

Fast heart beat, high temp, diarrhoea, vomiting

Question 12

What is the treatment for thyrotoxic crisis

Answer 12

Emergency treatment with IV fluids

Propranolol (blocks conversion of T4 to active T3),

Hydrocortisone and oral iodine solution, carbimazole or propylthiouracil

Radioactive sodium also used

Question 13

Is radioactive iodine contraindicated in pregnancy?

Answer 13

Yes