Contraindications for Calcium Channel Blockers
Calcium channel blockers are absolutely contraindicated in patients with second- or third-degree AV block without a pacemaker, sick sinus syndrome, severe left ventricular dysfunction, and immediate-release nifedipine should never be used in acute coronary syndromes without concurrent beta-blocker therapy. 1
Absolute Contraindications
Cardiac Conduction Abnormalities
- Second- or third-degree AV block without a cardiac pacemaker is an absolute contraindication for all non-dihydropyridine CCBs (verapamil, diltiazem) 2, 1, 3
- Sick sinus syndrome contraindicates all CCBs due to risk of severe bradycardia and cardiac arrest 2, 1, 3
- PR interval >0.24 seconds is a contraindication specifically for non-dihydropyridines 1
Severe Left Ventricular Dysfunction
- Clinically significant left ventricular dysfunction or heart failure with reduced ejection fraction contraindicates non-dihydropyridine CCBs (verapamil, diltiazem) 1, 4, 5
- Most CCBs except amlodipine should be avoided in heart failure with reduced ejection fraction due to negative inotropic effects 1, 3
- Verapamil has the greatest negative inotropic effect, followed by diltiazem, then nifedipine 3
Acute Coronary Syndromes
- Immediate-release nifedipine is absolutely contraindicated in acute coronary syndromes without beta-blockade, as it causes dose-related increases in mortality 2, 1, 4
- Non-dihydropyridine CCBs should not be used in NSTE-ACS patients with left ventricular dysfunction or increased risk for cardiogenic shock 4
Severe Aortic Stenosis
- Advanced or severe aortic stenosis is listed as a contraindication for CCBs in hypertensive emergencies 2
- Recent research shows CCB use in moderate-to-severe AS was associated with 7-fold increased mortality risk (HR 7.09; 95% CI 2.15-23.38) 6
Relative Contraindications and High-Risk Situations
Combination Therapy Risks
- Verapamil or diltiazem should never be combined with beta-blockers in patients with LV dysfunction due to excessive bradycardia or heart block risk 1
- Diltiazem and verapamil must not be combined with ivabradine due to severe bradycardia risk 1
- Combining two dihydropyridine CCBs increases hypotension and peripheral edema risk 7
Cardiogenic Shock Risk Factors
- Age >70 years, heart rate >110 bpm, systolic BP <120 mm Hg, and late presentation increase shock risk with CCBs 1, 4
- Volume-depleted patients are at increased risk for profound hypotension 2
- Diastolic BP <60 mm Hg in patients with diabetes or age >60 years may worsen myocardial ischemia 1
Special Clinical Contexts
Pediatric Pulmonary Hypertension
- CCBs are contraindicated in children who have not undergone or are nonresponsive to acute vasoreactivity testing 2
- CCBs are contraindicated in patients with right-sided heart dysfunction due to negative inotropic effects 2
Cocaine-Associated Chest Pain
- Short-acting nifedipine should never be used in cocaine-associated ACS 2
- Verapamil or diltiazem should be avoided in patients with evidence of heart failure or left ventricular dysfunction in this setting 2
- CCBs should not be first-line treatment but may be considered only after benzodiazepines and nitroglycerin have failed 2
Common Pitfalls to Avoid
- Do not use CCBs as monotherapy for peripheral vascular disease or claudication—there is no supporting evidence 7
- Avoid prescribing CCBs in patients with Q-wave myocardial infarction and concomitant left ventricular dysfunction, as they are less effective than beta-blockade 5
- Never use immediate-release nifedipine for hypertension management due to unpredictable BP response and mortality risk 2, 1
- When CCBs are indicated in coronary disease, dihydropyridines require concomitant beta-blocker therapy 7