What is the dose of Diltiazem (Diltiazem) intravenous (IV) for atrial fibrillation (afib) with rapid ventricular response (RVR)?

From the Guidelines

For atrial fibrillation with rapid ventricular response (AFib with RVR), the recommended IV diltiazem dosing is an initial bolus of 0.25 mg/kg (typically 15-20 mg) administered over 2 minutes, as supported by the 2010 American Heart Association guidelines 1. This initial dose can be followed by a second bolus of 0.35 mg/kg (typically 20-25 mg) if the ventricular rate remains elevated after 15 minutes. After achieving rate control with bolus doses, a continuous infusion should be started at 5-15 mg/hour, titrated to maintain heart rate below 100 beats per minute, with the maximum recommended infusion rate generally being 15 mg/hour. Key considerations include:

• Monitoring blood pressure closely during administration due to the risk of hypotension, a common side effect.
• Using diltiazem cautiously in patients with heart failure, hypotension, or those on beta-blockers due to potential additive effects.
• Transitioning to oral diltiazem or another rate control agent for long-term management once the patient is stabilized. The use of diltiazem for rate control in AFib with RVR is further supported by the 2011 ACCF/AHA/HRS focused updates incorporated into the ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation 1, emphasizing the importance of controlling the ventricular rate to improve symptoms and reduce the risk of complications.

From the FDA Drug Label

The initial dose of diltiazem hydrochloride injection should be 0.25 mg/kg actual body weight as a bolus administered over 2 minutes (20 mg is a reasonable dose for the average patient). If response is inadequate, a second dose may be administered after 15 minutes. The second bolus dose of diltiazem hydrochloride injection should be 0.35 mg/kg actual body weight administered over 2 minutes (25 mg is a reasonable dose for the average patient).

The recommended initial dose of diltiazem for afib with rvr is 0.25 mg/kg as a bolus, which can be repeated with a second dose of 0.35 mg/kg after 15 minutes if response is inadequate.

• Key points:
  • Initial bolus dose: 0.25 mg/kg
  • Second bolus dose: 0.35 mg/kg
  • Administration: over 2 minutes
  • Average patient dose: 20 mg for the initial dose, 25 mg for the second dose 2

From the Research

Diltiazem Dose IV for Afib with RVR

• The ideal dose of IV diltiazem for afib with RVR is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
• However, the studies suggest that IV diltiazem is effective in achieving rate control in patients with afib with RVR, with some studies showing it to be more effective than metoprolol 5, 6.
• The studies also report that IV diltiazem is associated with a similar incidence of adverse effects, such as hypotension and bradycardia, compared to metoprolol 3, 5, 6, 7.
• In terms of specific dosing, the studies do not provide a clear recommendation, but they do suggest that the dose of IV diltiazem should be titrated to achieve the desired heart rate control while minimizing the risk of adverse effects 4, 7.

Key Findings

• IV diltiazem is effective in achieving rate control in patients with afib with RVR 5, 6.
• IV diltiazem is associated with a similar incidence of adverse effects, such as hypotension and bradycardia, compared to metoprolol 3, 5, 6, 7.
• The dose of IV diltiazem should be titrated to achieve the desired heart rate control while minimizing the risk of adverse effects 4, 7.

Study Limitations

• The studies have limitations, including small sample sizes, variability in dosing, and limited representation of important patient subgroups 3, 7.
• The studies also have conflicting results, with some showing IV diltiazem to be more effective than metoprolol, while others show no difference 5, 6, 7.