From the Guidelines
To titrate a diltiazem (Cardizem) drip, start with an initial infusion rate of 5-15 mg/hour after administering a loading dose of 15 to 20 mg (0.25 mg/kg) IV over 2 minutes, and adjust as needed to achieve the target heart rate or blood pressure, with a maximum recommended dose of 15 mg/hour, as recommended by the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 1. The initial loading dose should be administered over 2 minutes, and if needed, an additional dose of 20 to 25 mg (0.35 mg/kg) can be given in 15 minutes. Key considerations for titration include:
- Monitoring the patient's blood pressure and heart rate every 5-15 minutes initially, then every 30 minutes once stable
- Increasing the dose by 5 mg/hour every 15-30 minutes as needed to achieve the target heart rate (usually 60-100 beats per minute) or blood pressure
- Decreasing the infusion rate if the patient develops hypotension (systolic blood pressure below 90 mmHg) or bradycardia (heart rate below 60 beats per minute)
- Documenting vital signs, dose changes, and patient response throughout the titration process Diltiazem works by blocking calcium channels in the heart and blood vessels, which slows conduction through the AV node and causes vasodilation, making it effective for rate control in atrial fibrillation/flutter and other supraventricular tachycardias, as supported by guidelines from the American College of Cardiology, American Heart Association, and European Society of Cardiology 1.
From the FDA Drug Label
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From the Research
Titrating a Diltiazem Drip
To titrate a diltiazem drip, consider the following steps:
- Start with a loading dose, if necessary, and then begin the continuous infusion at a rate of 5-15 mg/hour, titrating to achieve the desired heart rate or blood pressure response 2.
- Monitor the patient's heart rate, blood pressure, and electrocardiogram (ECG) closely during the titration process, as diltiazem can cause hypotension, bradycardia, and conduction disturbances 3, 4.
- Adjust the infusion rate in small increments (e.g., 2.5-5 mg/hour) and reassess the patient's response after 5-10 minutes before making further adjustments 2.
- Be aware of the potential for acute kidney injury, particularly in patients with decreased ejection fraction, and monitor renal function during the titration process 3.
Considerations for Specific Patient Populations
- In patients with atrial fibrillation or flutter, diltiazem may be more effective than metoprolol for achieving rate control, with a more rapid and substantial decrease in heart rate 2.
- In patients with contraindications to beta-blockers, diltiazem may be a suitable alternative for reducing heart rate in coronary artery computed tomography angiography 5.
- In patients with reduced ejection fraction, diltiazem may be associated with an increased risk of acute kidney injury, but not increased risk of hypotension, intensive care unit transfer, or in-hospital mortality 3.