Endocrine (Anti-Thyroid Drugs - Thionamides)

Question 1

Examples of drug (Anti-Thyroid Drugs - Thionamides)

Answer 1

• Carbimazole

- Propylthiouracil

Question 2

Mechanism of action (Anti-Thyroid Drugs - Thionamides)

Answer 2

• Reduces activity of peroxidase enzyme (required for the production of thyroid hormones)
• May also reduce peripheral conversion of T4 to T3
• Carbimazole is a pro-drug

Question 3

Indications (Anti-Thyroid Drugs - Thionamides)

Answer 3

• Hyperthyroidism
• Thyrotoxicosis
• Preparing patients for thyroid surgery

Question 4

Side-effects (Anti-Thyroid Drugs - Thionamides)

Answer 4

• Rash
• Agranulocytosis
• Sore throat

Question 5

Important pharmacokinetics/pharmacodynamics (Anti-Thyroid Drugs - Thionamides)

Answer 5

• Carbimazole is rapidly metabolised to thiamazole. The mean peak plasma concentration occurs one hour
• It crosses the placenta and can be found in breast milk
• The effect of anti-thyroid drugs can take several weeks to occur so are usually prescribed alongside a beta-blocker to reduce symptoms of hyperthyroidism

Question 6

Patient information (Anti-Thyroid Drugs - Thionamides)

Answer 6

• Compliance is important

- Regular blood checks will be needed to monitor treatment response and renal, hepatic function and full blood counts.