Class I Antiarrhythmic Drugs

Question 1

Ia: Disopyramide, procainamide, quinidine

Ib: Lidocaine, mexiletine

Ic : Flecainide. propafenone

Answer 1

Block the sodium channels in the cell membrane during an action potential

Question 2

THERAPEUTIC ACTION

What does this drug do to our body?

Answer 2

Decreases depolarization, decreasing automaticity of the ventricular cells; increases ventricular fibrillation threshold

Question 3

INDICATION

Why are we giving this drug?

Answer 3

Management of acute ventricular arrhythmias during cardiac surgery or MI

Question 4

CONTRAINDICATIONS

When NOT to give the drug

Answer 4

Allergy
bradycardia or heart block
CHF
hypotension or shock
electrolyte disturbances

Question 5

CAUTIONS

Answer 5

Renal or hepatic dysfunction

pregnancy

Question 6

ADVERSE EFFECTS

What we are monitoring for

Answer 6

CNS effects: Dizziness, fatigue, slurred speech

GI – Nausea and vomiting

CV – Arrhythmias

Respiratory depression

Misc. – Rash, loss of hair, and potential bone marrow suppression

Question 7

DRUG - DRUG INTERTACTIONS

Answer 7

Quinidine & digoxin
Oral anticoagulants
Digoxin and Beta-blockers

Question 8

DRUG-FODD INTERACTIONS

Answer 8

Foods that alkalinize the urine (citrus juice, vegetables, antacids, milk products)
Grapefruit juice

Question 9

PROTOTYPE

Answer 9

LIDOCAINE