Amiodarone

Question 1

What class of drug is Amiodarone?

Answer 1

Class III, potassium channel blocker

Question 2

What are the common indications for Amiodarone?

Answer 2

Wide spread use

* Most arrhythmias (especially ventricular tachycardia)

Question 3

What is the mechanism of action of Amiodarone?

Answer 3

It’s main mechanism of action is blocking potassium channels

Increased the refractory period and AP duration (Increased QRS and QT)

It has some action as a Na+, Ca2+ and beta blocker - decreased phase 0 and conduction, increase AP threshold, decrease phase 4 and decrease speed of AV conduction (Increased PR and decreased HR)

Question 4

What are the common adverse reactions of Amiodarone?

Answer 4

• pulmonary fibrosis (breathlessness)
• hepatic injury
• increase LDL cholesterol
• thyroid disease (as amiodarone has a high iodine content)
• photosensitivity
• optic neuritis

Question 5

What are the common drug-drug interactions of Amiodarone?

Answer 5

• May need to reduce digoxin dose

* May need to monitor warfarin more closely