Amiodarone

Question 1

Introduction to the drug

Answer 1

• Amiodarone is an oral and injectable drug that is used to correct abnormal rhythms of the heart.
• Amiodarone is considered a “broad spectrum” antiarrhythmic medication, that is, it has multiple and complex effects on the electrical activity of the heart which is responsible for the heart’s rhythm. Among its most important electrical effects are:
• a delay in the rate at which the heart’s electrical system “recharges” after the heart contracts (repolarization);
• a prolongation in the electrical phase during which the heart’s muscle cells are electrically stimulated (action potential);
• a slowing of the speed of electrical conduction (how fast each individual impulse is conducted through the heart’s electrical system);
• a reduction in the rapidity of firing of the normal generator of electrical impulses in the heart (the heart’s pacemaker);
• a slowing of conduction through various specialized electrical pathways (called accessory pathways) which can be responsible for arrhythmias.

Question 2

Presentation of the drug

Answer 2

• Pre filled syringe 300mg in 10ml

Question 3

Why would you prescribe this drug

Answer 3

• Ventricular arrhythmia

- Cardiac Arrest (Shockable rhythm)

Question 4

Typical dose

Answer 4

• Cardiac Arrest (shockable rhythm) After 3rd Shock

- Adults = 300mg initial, Repeat 150mg Max 450mg

Question 5

Pharmacodynamics

Answer 5

• Lengthens cardiac action potential and therefore refractory period
• Prolongs QT interval on ECG
• Blocks sodium/ potassium channels in cardiac muscle
• Stabilises and reduce electrical irritability of cardiac muscle

Question 6

Pharmacokinetics

Answer 6

• ## Amiodarone is eliminated primarily by hepatic metabolism and biliary excretion and there is negligible excretion of Amiodarone or DEA in urine.

Question 7

Side Effects

Answer 7

• Bradycardia
• Vasodilation
• Hypotension
• Bronchospasm
• Arrtyhmias