Amiodarone

Amiodarone (Cordarone, Sedacoron)

Mechanism of action

• Primarily blocks potassium channels of myocardial cells which prolongs their repolarisation and refractoriness and slows the conduction in the AV node.
• Secondly, it interferes with many other channels and receptors – acts as a nonselective beta-blocker, blocks sodium and calcium channels, causes peripheral vasodilation and even binds to thyroid receptors. 

Indications and dose

Pharmacokinetics

Onset of action: 7 days 

Duration of action: 10 days to 1 month after withdrawal

Half-life of elimination: 

• 3.2–20.7 hours after single dose
• 15–142 day after repetitive dosing

Metabolism: Hepatic (CYP3A4, CYP2C8) metabolization to desethylamiodarone (DEA)

Elimination: Liver 

Directions for administration

Infusion: administration via a central line is recommended.

Peroral: patient should be switched to peroral medication once an adequate response from initial IV administration has been obtained. Consumption of high-fat food before administration enhances absorption. 

Medicinal forms

Pills – 200 mg

Solution for injection/Infusion (50 mg/ml)

• 1 vial = 3 ml (150 mg)

Side-effects

Acute: 

• Bradycardia
• Sinus arrest, sino-atrial heart block
• Hypotension
• QT interval prolongation 
• Extrapyramidal tremor

Chronic

• Pulmonary fibrosis
• Hypothyroidism / Hyperthyroidism 
• Photosensitivity, grey-blue pigmentation of skin (mostly face)
• Eczema
• Corneal microdeposits (asymptomatic)
• Sleep disorders

‍

References

1. Amiodarone Uses, Dosage & Side Effects - Drugs.com
2. Pharm 101: Amiodarone • LITFL • Top 200 Drugs
3. Amiodarone: Uses, Interactions, Mechanism of Action | DrugBank Online
4. Amiodarone 200mg Tablets - Summary of Product Characteristics (SmPC) - (emc) (medicines.org.uk)

‍