Critical Care Trauma Centre

VERAPAMIL (Isoptin)

 

Name: VERAPAMIL (IsoptinR)
Classification: calcium channel blocker
  • decreases supraventricular tachyarrhythmias
  • decreases cardiac output
  • coronary vasodilator (in presence of cardiac disease, beta blockers, or hepatic failure)
Dose:
  • Bolus:
    • 5-10mg IV direct (over one minute)
Administration: IV Infusion:
50mg/100 mL dextrose 5%, sodium chloride 0.9% or Ringer's Lactate (maximum concentration 100mg/100mL)
  • should be weaned off
Adverse Effects:
  • hypotension (especially with rapid administration)
  • decreased cardiac output
  • arrhythmias
  • bradycardia
  • AV block, asystole
  • prolonged QT 
  • flushing
  • hepatic dysfunction
  • dizziness
  • dyspnea
  • headache
Caution:
  • contraindicated in patients with hypotension, sick sinus syndrome, second and complete AV block, and in patients with acute myocardial infarction and pulmonary edema
  • use cautiously in patients with AV conduction delays or transient sinus pauses
  • use cautiously with digoxin and beta blockers
  • use with caution in heart failure
  • do not administer to wide complex tachycardias unless VT has been ruled out
Antidote:
  • toxic cardiac effects may be treated with 1-2g calcium gluconate IV or 1mg atropine IV
Drug Interactions:
  • verapamil + digoxin = increased serum digoxin levels; depression of AV node
  • verapamil + propranolol = additive negative inotropic effects and cardiac depressant effects
  • verapamil + beta-agonists = decreased action of verapamil
  • verapamil + theophylline = increased theophylline level
Monitoring Therapy:
  • continuous heart rate and rhythm
  • PR and QT intervals
  • blood pressure
Adult Critical Care Protocol:
  • May be administed IV direct or by IV infusion by a nurse in Adult Critical Care
  • Continuous infusions must be administered by infusion device with pump library enabled.


Lynne Kelly, Pharmacist, CCTC
Brenda Morgan, Clinical Nurse Specialist, CCTC
Last Update: September 20, 2018