Anti-dysrhythmics

Question 1

What are the generic and brand names of Anti-dysrhythmics?

Answer 1

• Amiodarone (Cordarone)

* Flecainide

Question 2

What is the method of action of anti-dysrhythmics?

Answer 2

• Prolongs phase III of cardiac potential – repolarization
• Blocks Na and L activated myocardial adenosine triphosphatase
• Inhibits alpha and beta adrenergic receptors
• ↓ spontaneous depolarization through AV node
• ↓ chance of slow conduction velocity through AV node

Question 3

What are the indications of anti-dysrhythmics?

Answer 3

• Wide range of tachycardia’s – not first line
• AF
• Atrial flutter
• SVT
• VT
• Refractory VF (including cardiac arrest)

Question 4

What are the contraindications of anti-dysrhythmics?

Answer 4

• Severe hypotension
• Heart block
• Active thyroid disease

Question 5

What are the side effects of anti-dysrhythmics?

Answer 5

• Hypotension – mainly during IV infusions
• Pneumonitis
• Bradycardia
• AV block
• Hepatitis
• Photosensitivity
• Grey discolorations
• Hyper/hypothyroidism – due to being structurally similar to thyroid hormone

Question 6

What are the interactions with anti-dysrhythmics?

Answer 6

• Interacts with many drugs! – drug dose should be halved
• Digoxin – increases plasma concentration
• Diltiazem – increases plasma concentration
• Verapamil – increases plasma concentration

Question 7

What patient information should be given to patients on anti-dysrhythmics?

Answer 7

• Report any breathlessness, persistent cough, jaundice, restlessness, weight loss/gain, tiredness
• Do not drink grapefruit - ↑ side effects
• Avoid exposure of skin to sunlight - ↑ sensitivity