Procainamide

Question 1

Generic Name for Procainamide

Answer 1

Procainamide HCL

Question 2

Trade Name for Procainamide

Answer 2

Pronestyl

Question 3

Classification for Procainamide

Answer 3

ventricular and supraventricular antiarrhythmic (Class Ia)

Question 4

Procainamide is supplied in?

Answer 4

1 gm/10 mL (100 mg/mL)

Question 5

Pharmacodynamics for Procainamide

Answer 5

❑ Antiarrhythmic: Blocks open sodium channels and prolongs the cardiac action potential (outward potassium (K+) currents maybe blocked.) Decreases myocardial excitability, conduction velocity and may depress contractility.
❑ Prolongs PR and QT intervals.
❑ Has peripheral vasodilatory properties which may result in hypotension.

Question 6

Indications for Procainamide (4 points)

Answer 6

❑ stable monomorphic VT with normal QT interval and preserved LV function
❑ stable reentry SVT uncontrolled by adenosine and vagal maneuvers
❑ Stable wide complex tachycardia of unknown origin
❑ A-fib with rapid rate in WPW

Question 7

Dosages for Procainamide

Answer 7

Adult: Loading dose 20 to 50 mg/min IV until:
-arrhythmia suppressed
-hypotension
-QRS prolonged by 50%
-total cumulative dose of 17 mg/kg
If conversion is successful, may use maintenance infusion (avoid if prolonged QT or CHF);
-Mix: 1 gm/250 ml NS (4mg/mL); Infuse at 1-4 mg/min

Pediatric: 15mg/kg IV/IO load over 30 to 60 minutes

Question 8

Contraindications for Procainamide (9)

Answer 8

❑ Hypersensitivity to: 
-procainamide
-ester type local anesthetics
-benzyl alcohol
-sulphites
❑ Digoxin toxicity or TCA induced dysrhythmia 
❑ Atypical V-Tach (Torsades de Pointes)
❑ 2nd or 3rd degree AV block
❑ Preexisting QT prolongation
❑ Myasthenia gravis
❑ SLE - Lupus
❑ Pre-excitation with preexisting QT prolongation

Question 9

Precautions for Procainamide

Answer 9

❑ Reduce max total dose to 12 mg/kg if cardiac or renal dysfunction is present
❑ Pro-arrhythmic, especially in setting of AMI, hypokalemia or hypomagnesemia
❑ May induce hypotension is pts with impaired LV function
❑ Use with caution with other drugs that prolong QT interval (like amiodarone), expert consultation is needed.

Question 10

Noteworthy notes for Procainamide

Answer 10

❑ Obtain a baseline vitals and ECG strip

❑ If given too rapidly or if increased plasma concentration→ induced hypotension