What are the alternatives to diltiazem (Cardizem) 24 ER (extended release) for patients?

Alternatives to Diltiazem 24 ER

For most patients requiring an alternative to diltiazem ER, beta-blockers (such as metoprolol or atenolol) are the preferred first-line substitution, with verapamil as a reasonable alternative calcium channel blocker if beta-blockers are contraindicated or not tolerated. 1

Primary Alternatives Based on Indication

For Hypertrophic Cardiomyopathy (HCM)

• Beta-blockers are the first-line alternative and should be titrated until physiologic beta-blockade is achieved (evidenced by resting heart rate suppression) 1
• Verapamil is a reasonable second-line alternative to diltiazem for symptomatic relief in obstructive HCM, though it carries important safety warnings 1
  • Verapamil is potentially harmful in patients with severe dyspnea at rest, hypotension, very high resting gradients (>100 mm Hg), and all children <6 weeks of age 1
• For refractory cases, escalation options include mavacamten (cardiac myosin inhibitor in adults only), disopyramide, or septal reduction therapy at comprehensive HCM centers 1

For Hypertension

• Thiazide or thiazide-type diuretics (chlorthalidone 12.5-25 mg daily preferred over hydrochlorothiazide due to longer half-life and proven CVD reduction) 1
• ACE inhibitors (lisinopril 10-40 mg daily, enalapril 5-40 mg daily) or ARBs (losartan 50-100 mg daily, valsartan 80-320 mg daily) 1
• Beta-blockers (metoprolol succinate 50-200 mg daily, atenolol 25-100 mg daily) 1
• Dihydropyridine calcium channel blockers (amlodipine 2.5-10 mg daily, nifedipine LA 30-90 mg daily) if no contraindications exist 1

For Supraventricular Tachycardia (SVT/AVNRT)

• Verapamil is the preferred alternative for both acute termination and ongoing management of AVNRT 1
• Beta-blockers (intravenous or oral) are reasonable alternatives with excellent safety profiles 1
• Catheter ablation of the slow pathway is first-line definitive therapy and should be strongly considered as it is potentially curative 1

For Angina and Ischemic Heart Disease

• Beta-blockers are the drugs of first choice for angina in patients with CAD, particularly cardioselective β1-agents without intrinsic sympathomimetic activity 1
• Long-acting dihydropyridine calcium channel blockers (amlodipine, felodipine) can be added to or substituted for beta-blockers when BP remains elevated or angina persists 1
• Verapamil is a reasonable alternative when beta-blockers are contraindicated or produce intolerable side effects, but should not be used in patients with LV dysfunction 1, 2

Key Clinical Considerations

When Beta-Blockers Are Preferred Over Diltiazem

• Patients with prior MI or heart failure (Class I ACC/AHA recommendation) 1
• Obstructive HCM as first-line therapy 1
• Angina with coronary artery disease 1

When Verapamil May Be Chosen Over Diltiazem

• Similar efficacy profile for hypertension, angina, and SVT 1, 2
• Dosing: Start low and titrate up to 480 mg/day for symptom control 2
• Same contraindications apply: Avoid in LV systolic dysfunction, heart failure, significant AV block, hypotension 2
• Caution with beta-blocker combination due to increased risk of bradyarrhythmias 2

Critical Contraindications to Consider

When selecting alternatives, ensure the patient does not have contraindications to the chosen agent:

• Beta-blockers: Avoid in severe bronchospastic disease, significant sinus/AV node dysfunction, decompensated HF, hypotension 1
• Verapamil/Diltiazem: Avoid in HF with reduced ejection fraction, second/third-degree AV block without pacemaker, severe LV dysfunction 1, 2
• Dihydropyridines: Avoid in obstructive HCM as they can worsen outflow tract obstruction 1

Practical Algorithm for Selection

1. Identify the primary indication for diltiazem (HCM, hypertension, angina, SVT)
2. For HCM: Switch to beta-blocker first-line; consider verapamil if beta-blocker fails or is contraindicated 1
3. For hypertension alone: Choose thiazide diuretic, ACE inhibitor, or ARB based on comorbidities 1
4. For angina/CAD: Switch to beta-blocker; add long-acting dihydropyridine if needed 1
5. For SVT: Consider verapamil or proceed directly to catheter ablation for definitive cure 1
6. Assess for contraindications to each alternative before prescribing
7. Monitor closely during transition: BP, heart rate, symptoms, and ECG if conduction disease present 1