Chapter 23 Antidysrhythmic Drugs

Question 1

Class 1a

Answer 1

• Act on phase 0

- procainamide and disopyramide

Question 2

Class 2 (Beta Blockers)

Answer 2

• acebutolol, esmolol, propranolol
• Reduce or block the sympathetic nervous system stimulation (adrenergic receptors), thus reducing transmission of impulses in the hearts conduction system
• Depress phase 4 depolarization
• B1 and B2 (selective or nonselective)
• Adverse effects: could exacerbate asthma or COPD, muscular pain, NKA, second or third degree heart block, diarrhea, constipation, weakness

Question 3

Class 3

Answer 3

• Amiodarone
• Increases APD (action potential duration)
• Prolong repolarization in phase 3
• Used for dysrhythmias that are difficult to treat
• Longer duration of action because the drug is lipophilic
• Adverse effects: photosensitivity, skin discoloration (blue/grey), numbness, tingling, blurred vision

Question 4

Nursing Considerations

Answer 4

• Check grapefruit interaction with cardiac meds

Question 5

Class 4 (Calcium Channel Blockers)

Answer 5

• verapamil and diltiazem (Cardizem)
• Inhibit CA2+ dependent pathways
• Depress phase 4 depolarization
• Reduce AV node conduction
• Adverse effects: diarrhea, constipation, dizziness, nausea, dysryhthmias, depression