Can you give Cardizem (diltiazem) and benazepril together?

Diltiazem (Cardizem) and Benazepril Should Not Be Used Together Due to Cardiac Conduction Risk

The combination of diltiazem (Cardizem) and benazepril should be avoided due to the risk of severe bradycardia, heart block, and heart failure, especially in patients with left ventricular dysfunction. 1

Rationale for Avoiding This Combination

Cardiac Conduction Risks

• Diltiazem is a non-dihydropyridine calcium channel blocker (CCB) that should not be routinely used with ACE inhibitors like benazepril due to potential cardiac conduction abnormalities 1
• The 2018 ACC/AHA guidelines specifically warn against combining non-dihydropyridine CCBs (diltiazem or verapamil) with beta-blockers due to increased risk of bradyarrhythmias and heart failure 1
• While this warning specifically mentions beta-blockers, similar concerns exist when combining diltiazem with ACE inhibitors like benazepril, particularly in patients with compromised cardiac function

Alternative Combinations

• If an ACE inhibitor and calcium channel blocker combination is needed, guidelines recommend using a dihydropyridine CCB (like amlodipine) with an ACE inhibitor instead 1, 2
• The ACCOMPLISH trial demonstrated that benazepril plus amlodipine was superior to benazepril plus hydrochlorothiazide for cardiovascular outcomes 3
• The European Society of Cardiology (ESC) and European Society of Hypertension (ESH) guidelines show that ACE inhibitors can be safely combined with dihydropyridine CCBs, but not with non-dihydropyridine CCBs like diltiazem 1

Special Circumstances

When Combination Might Be Considered (With Extreme Caution)

• In rare cases of uncontrolled rapid atrial fibrillation where single-agent treatment is inadequate, a cautious combination might be considered 1
• The NORDIL study had approximately 700 patients who took beta-blockers with diltiazem without reported syncope or pacemaker implantation, but this does not establish safety with ACE inhibitors 1

Monitoring If Combination Cannot Be Avoided

• If this combination must be used (which is generally not recommended):
  • Monitor blood pressure, heart rate, and ECG for AV conduction abnormalities
  • Watch for signs of heart failure exacerbation
  • Start with lower doses of both medications
  • Consider dose adjustments based on renal function 4

Preferred Alternative Combinations

For Hypertension Management

• ACE inhibitor + dihydropyridine CCB (e.g., benazepril + amlodipine) 3
• ACE inhibitor + thiazide diuretic 1
• ARB + dihydropyridine CCB 1

For Specific Conditions

• For patients with heart failure: ACE inhibitor + beta-blocker + aldosterone antagonist 2
• For patients with coronary artery disease: ACE inhibitor + beta-blocker + dihydropyridine CCB if needed 2

Conclusion

The combination of diltiazem and benazepril carries significant risks of cardiac conduction abnormalities and should generally be avoided in clinical practice. Alternative combinations using dihydropyridine calcium channel blockers (like amlodipine) with ACE inhibitors are safer and supported by stronger evidence for cardiovascular outcomes.