What is the recommended dosage of Verapamil (calcium channel blocker) for rate control?

Verapamil Dosage for Rate Control

For rate control in atrial fibrillation, the recommended intravenous verapamil dosage is 2.5-10 mg given over 2 minutes, which may be repeated as 5-10 mg every 15-30 minutes to a total dose of 20-30 mg. 1

Intravenous Verapamil Dosing

• Initial dose: 2.5-5 mg IV bolus over 2 minutes (use 3 minutes in older patients) 1
• If no therapeutic response and no adverse effects occur, repeated doses of 5-10 mg may be administered every 15-30 minutes 1
• Maximum total dose: 20-30 mg 1
• Alternative regimen: 5 mg bolus every 15 minutes to a total dose of 30 mg 1

Oral Verapamil Dosing for Long-term Rate Control

• Standard dosing: 40-120 mg three times daily 1
• Extended/sustained-release formulation: 120-480 mg once daily 1
• Typical maintenance dose range: 120-360 mg daily in divided doses 1

Important Considerations and Contraindications

• Verapamil should only be administered to patients with narrow-complex tachycardias or arrhythmias known with certainty to be of supraventricular origin 1
• Verapamil is contraindicated in patients with:
  • Wide-complex tachycardias 1
  • Impaired ventricular function or heart failure 1
  • Left ventricular ejection fraction <40% 1
  • Pre-excited atrial fibrillation or flutter 1

Side Effects and Monitoring

• Common adverse effects include:
  • Hypotension (potentially prolonged) 1
  • Bradycardia 1
  • Atrioventricular block 1
  • Heart failure precipitation 1
• Monitor for hemodynamic stability during administration 1
• Use with caution in combination with beta-blockers 1

Clinical Pearls

• For acute rate control in atrial fibrillation, verapamil is a Class I recommendation with Level of Evidence B 1
• In critically ill patients with severely impaired LV function, intravenous amiodarone may be preferred over verapamil for rate control 1
• Verapamil has negative inotropic effects and should be avoided in patients with heart failure 1
• For patients requiring long-term rate control, beta-blockers are often considered first-line therapy, with calcium channel blockers like verapamil as alternatives 1
• When transitioning from IV to oral therapy, consider the pharmacokinetics of verapamil, which has a half-life of approximately 3-7 hours 1, 2

Dosage Adjustments

• Consider lower initial doses in:
  • Elderly patients (administer initial IV dose over 3 minutes) 1
  • Patients with hepatic impairment 1
  • Patients with renal impairment (start with smaller doses) 1
• For patients requiring long-term therapy, twice-daily dosing of 120 mg may be as effective as three times daily dosing and may improve compliance 3