Amiodarone

Question 1

Loading dose of Amiodarone

Answer 1

200mg TDS 7 days
200mg BD 7 days
200mg OD maintenance

Question 2

Side effects of Amiodarone

Answer 2

o Bradycardia
o Corneal microdeposits (blurred vision)
o Thyroid dysfunctions
o Photosensitivity reaction
o Hepatotoxicity
o Pulmonary toxicity
o Impaired driving and skilled tasks

Question 3

Interactions with Amiodarone

Answer 3

Very long half-life = potential for interactions after several weeks or months

Drugs that cause hypokalaemia
Drugs that cause QT prolongation
CYP450 enzyme substrates (amiodarone = inhibitor)
Other enzyme inhibitors (grapefruit will increase conc of amiodarone because grapefruit juice is an inducer) and inducers will affect amiodarone too e.g., warfarin, contraceptives, statins
Drugs that cause bradycardia

Question 4

Monitoring of Amiodarone

Answer 4

Thyroid function tests: before treatment, then every 6 months

Live function tests: before treatment and then every 6 months

Serum potassium concentration: before treatment

Chest x-ray: before treatment as it can cause pulmonary toxicity

Annual eye examination

IV use: ECG and liver transaminases

Question 5

Amiodarone and pregnancy

Answer 5

Risk of neonatal goitre; use only if no alternative