THYROXINE

Question 1

Drug class (3)

Answer 1

1. thyroid hormone
2. levothyroxine
3. liothyronine

Question 2

How does it work? (3)

Answer 2

1. T4 = Levothyroxine
2. converted into T3 (active form) triodothyronine
3. regulate metabolism and growth

Question 3

Indications

Answer 3

hypothyroidism

Question 4

Contraindications (2)

Answer 4

1. heart

• cardiac ischaemia
• coronary artery disease

2. hypopituitarism
   - must give cortisol to prevent Addison’s disease

Question 5

Side effects (4)

Answer 5

1. too much
   - hyperthyroidism
2. GI

• vomitting
• diarrhoea
• weight loss

3. Cardiac

• palpitations
• angina
• arrhythmias

4. neurological

• tremors
• restlessness
• insomnia

Question 6

Interactions (4)

Answer 6

1. antacids, iron, calcium and salt

• reduce absorption
• admin 4 hrs gap

2. cytochrome P450 inducers
   - increase levothyroxine
   e. g. phenytoin
3. diabetics
   - increases insulin requirements
4. warfarin
   - enhances it’s effects

Question 7

Elimination

Answer 7

urine