Procainamide

Question 1

Procainamide (Pronestyl)

Class

Answer 1

Antiarrhythmic

Question 2

Procainamide (Pronestyl)

Mechanism of Actions

Answer 2

Suppress phase 4 depolarization in normal ventricular muscle and Purkinje fibers, reducing ectopic pacemaker automaticity; suppresses intraventricular conduction.

Question 3

Procainamide (Pronestyl)

Indications

Answer 3

Stable monomorphic V-tach with normal QT interval, reentry SVT uncontrolled by vagal maneuvers or adenosine, stable wide-complex tachycardia of unknown origin, a-fib with rapid ventricular rate in patients with W-P-W.

Question 4

Procainamide (Pronestyl)

Contraindications

Answer 4

Torsade de pointes, second- or third-degree AV block (without functional pacemaker), digitalis toxicity, tricyclic antidepressant overdose.

Question 5

Procainamide (Pronestyl)

Adverse Reactions

Answer 5

Widening of the PR, QRS, and QT intervals, AV heart block, hypotension, reflex tachycardia, bradycardia, nausea, and vomiting.

Question 6

Procainamide (Pronestyl)

Drug Interactions

Answer 6

May increase plasma levels of amiodarone and quinidine.

Question 7

Procainamide (Pronestyl)

Adult Dosage

Answer 7

Recurrent V-fib/pulseless V-tach: 20 mg/min IV infusion (maximum dose 17 mg/kg). In urgent situations up to 50 mg/min may be administered. Maintenance infusion: 1 – 4 mg/min diluted in NS.

Question 8

Procainamide (Pronestyl)

Pediatric Dosage

Answer 8

Loading dose of 15 mg/kg IV/IO over 30 – 60 minutes.

Question 9

Procainamide (Pronestyl)

Onset

Answer 9

10 - 30 minutes

Question 10

Procainamide (Pronestyl)

Peak Effect

Answer 10

Variable

Question 11

Procainamide (Pronestyl)

Duration

Answer 11

3 - 6 hours

Question 12

Procainamide (Pronestyl)

Special Considerations

Answer 12

Hypotension may occur with rapid infusion. Administer cautiously in patients with renal, hepatic, cardiac insufficiency, asthma or digitalis-induced arrhythmias.