When to discontinue diltiazem (Cardizem) intravenous (IV) infusion?

From the Guidelines

Diltiazem drip should be stopped when the patient achieves adequate heart rate or blood pressure control, typically a heart rate below 100 beats per minute for atrial fibrillation or flutter, or when the patient is transitioned to oral medications. This decision is based on the guidelines for the management of adult patients with supraventricular tachycardia, which recommend the use of intravenous diltiazem for acute rate control in patients with atrial flutter who are hemodynamically stable 1. The guidelines also suggest that diltiazem should be avoided in patients with advanced heart failure and in patients with heart block or sinus node dysfunction in the absence of pacemaker therapy 1. Key considerations for stopping the diltiazem drip include:

• Achieving adequate heart rate or blood pressure control
• Transitioning to oral medications
• Developing significant hypotension (systolic blood pressure below 90 mmHg)
• Developing bradycardia (heart rate below 50 beats per minute)
• Exhibiting signs of heart failure such as increased shortness of breath or pulmonary edema It is essential to taper the infusion gradually rather than stopping it abruptly to prevent rebound tachycardia or hypertension 1. Regular monitoring of vital signs and cardiac rhythm is crucial during both administration and discontinuation of diltiazem infusion 1. Additionally, when transitioning to oral therapy, the first oral dose should typically be given 1-3 hours before stopping the infusion to ensure therapeutic levels are maintained 1. Diltiazem works by blocking calcium channels in cardiac tissue, which slows conduction through the AV node and reduces heart rate 1. Abrupt discontinuation can lead to sudden loss of these effects, potentially causing clinical deterioration 1.

From the FDA Drug Label

If high-degree AV block occurs in sinus rhythm, intravenous diltiazem should be discontinued and appropriate supportive measures instituted

The diltiazem drip should be stopped if high-degree AV block occurs in sinus rhythm 2.

From the Research

Stopping Diltiazem Drip

• The decision to stop a diltiazem drip should be based on the patient's response to treatment and their individual clinical needs 3.
• In patients with atrial fibrillation or flutter, the diltiazem drip can be stopped 4 hours after the first oral dose of long-acting diltiazem, as long as the patient has achieved stable heart rate control 3.
• The efficacy of oral long-acting diltiazem in controlling ventricular response has been shown to be 77% effective over 48 hours in patients with AF or AFl who were initially controlled with intravenous diltiazem 3.
• It is essential to monitor the patient's heart rate and other clinical parameters closely after stopping the diltiazem drip to ensure that they remain stable 3.

Clinical Considerations

• Diltiazem is a calcium-channel blocker that is commonly used to treat angina, hypertension, and certain types of arrhythmias, including atrial fibrillation and flutter 4, 5.
• The choice of drug for rate control in atrial fibrillation should be based on the patient's individual clinical needs and medical history, with consideration of factors such as efficacy, safety, and potential interactions with other medications 6.
• Therapeutic drug monitoring may be useful in certain cases, such as when using antiarrhythmic agents with a narrow therapeutic index, but is not typically necessary for calcium-channel blockers like diltiazem 7.