From the Guidelines
Cardizem (diltiazem) and amiodarone can be given together, but this combination should be used with caution due to potential drug interactions and overlapping effects on cardiac function. According to the 2016 ESC guidelines for the management of atrial fibrillation 1, amiodarone can be useful for rate control as a last resort, and the choice of rate control agents, including combination therapy with beta-blockers, diltiazem/verapamil, or digoxin, should be made on an individual basis.
When considering the use of Cardizem and amiodarone together, it is essential to be aware of the potential for additive effects on the heart's electrical conduction system, which may lead to excessive bradycardia, heart block, or hypotension. The guidelines suggest that combination therapy, such as beta-blocker or verapamil/diltiazem combined with digoxin, can be used for rate control in patients with atrial fibrillation 1.
Key considerations for using this combination include:
- Careful monitoring of electrocardiogram (ECG) to assess for PR interval prolongation, QT interval changes, and development of heart block
- Regular blood pressure monitoring to assess for hypotension
- Potential for amiodarone to increase diltiazem blood levels by inhibiting its metabolism, which may enhance both therapeutic and adverse effects
- The need for close supervision by a cardiologist or electrophysiologist to evaluate the risk-benefit ratio for the individual patient.
From the FDA Drug Label
In amiodarone-treated patients who require additional antiarrhythmic therapy, the initial dose of such agents should be approximately half of the usual recommended dose. Antihypertensives: Amiodarone should be used with caution in patients receiving ß- receptor blocking agents (e.g., propranolol, a CYP3A4 inhibitor) or calcium channel antagonists (e.g., verapamil, a CYP3A4 substrate, and diltiazem, a CYP3A4 inhibitor) because of the possible potentiation of bradycardia, sinus arrest, and AV block; Hemodynamic and electrophysiologic interactions have also been observed after concomitant administration with propranolol, diltiazem, and verapamil.
Cardizem (diltiazem) and amiodarone can be given together, but with caution due to the possible potentiation of bradycardia, sinus arrest, and AV block. The initial dose of Cardizem should be approximately half of the usual recommended dose 2.
From the Research
Combination of Cardizem and Amiodarone
- The combination of Cardizem (diltiazem) and amiodarone can be considered in certain cases, as both drugs are used to treat atrial fibrillation and other heart rhythm disorders 3, 4.
- However, it is essential to note that amiodarone can interact with other drugs, including calcium channel blockers like diltiazem, which may lead to adverse effects 5.
- A study found that diltiazem pretreatment was less effective than amiodarone in determining spontaneous or electric conversion of atrial fibrillation, but it may still be considered as a second-choice treatment in certain cases 4.
- Another study suggested that amiodarone can be used in combination with beta-blockers, but the dosage of beta-blockers should be reduced to prevent interactions 5.
- The use of amiodarone and diltiazem together may require careful monitoring of the patient's condition and adjustment of dosages to minimize potential adverse effects 6, 7.
Potential Benefits and Risks
- The combination of amiodarone and diltiazem may provide benefits in reducing the incidence of atrial fibrillation and other cardiovascular events, but it also carries potential risks, such as adverse interactions and increased toxicity 3, 7.
- A meta-analysis found that amiodarone prophylaxis decreased the incidence of atrial fibrillation, ventricular tachyarrhythmias, and stroke after cardiac surgery, but it also increased the risk of adverse events, such as nausea and bradycardia 7.
- Therefore, the decision to use amiodarone and diltiazem together should be made on a case-by-case basis, taking into account the individual patient's condition, medical history, and potential risks and benefits 3, 4.