Za Pharmacy
Drugs, Supplies and Delivery
Amiodarone
Amiodarone is a potent class III antiarrhythmic medication widely used to treat and prevent life-threatening ventricular and supraventricular arrhythmias. Despite its efficacy, amiodarone has a complex pharmacokinetic profile and a significant side effect profile, requiring careful monitoring. This article synthesizes information from the British National Formulary (BNF), Lippincott Textbook of Pharmacology, and Lange Basic & Clinical Pharmacology to provide a detailed overview of amiodarone, including its mechanism, uses, dosing, side effects, precautions, and drug interactions.
Amiodarone is a multi-channel blocker with effects on sodium, potassium, and calcium channels, as well as non-competitive beta-blocking activity. Its primary mechanisms include:
- Potassium Channel Blockade:
- Prolongs the action potential duration and refractory period by blocking potassium channels, particularly the rapid component of the delayed rectifier potassium current (IKr) (Lippincott, Lange).
- Sodium Channel Blockade:
- Slows conduction velocity by inhibiting sodium channels during phase 0 of the cardiac action potential (BNF).
- Calcium Channel Blockade:
- Reduces calcium influx, contributing to its antiarrhythmic effects (Lippincott).
- Beta-Blocking Activity:
- Non-competitively inhibits beta-adrenergic receptors, reducing sympathetic stimulation and heart rate (Lange).
Amiodarone’s broad-spectrum activity makes it effective for a wide range of arrhythmias.
