Name

Procainamide (Pronestyl®)

Class

Antidysrhythmic (Class I-A)

Description/Mechanism

Procainamide suppresses Phase 4 depolarization in normal ventricular muscle and Purkinje fibers, reducing the automaticity of ectopic pacemakers by decreasing sodium influx.

It also suppresses reentry dysrhythmias by slowing intraventricular conduction.

Onset

10-30 minutes

Duration

3-6 hours

Indications

VT/VF

SVT

Afib/Aflutter with uncontrolled ventricular response.

Contraindications

Second and third degree AV block

Digitalis toxicity

Torsades de pointes

Adverse Reactions

Hypotension

Bradycardia

Reflex tachycardia

AV block

Widened QRS

Prolonged PR or QT interval

Torsades des Pointes

PVCs

VT, VT, asystole

CNS depression

Confusion

Seizure

Drug Interactions

None significant

Supplied

1 g in 10 ml vials (100mg/ml)

1 g in 2 ml (500 mg/ml) for infusion

Dose/Administration

Adult

IV: 20 mg/min (30 mg/min in refractory VF) slow push (max total 17mg/kg). May give as 100 mg bolus every 5 minutes in cardiac arrest.

Infusion after conversion: 1-4 mg/ml

Discontinue if:

1) the dysrhythmia is suppressed

2) hypotension develops

3) the QRS complex widens by more than 50%

4) a total of 1 g is administered.

Pediatric

Not recommended.

Special Consideration

Pregnancy Safety: Category C

Procainamide has potent vasodilating and inotropic effects

Rapid injection may cause procainamide-induced hypotension.

Carefully monitor vital signs and ECG

Administer cautiously to patients with asthma, digitalis-induced dysrhythmias, AMI or cardiac, hepatic, or renal insufficiency