What is the preferred treatment between Procardia (nifedipine) and diltiazem for hypertension and angina?

Diltiazem vs. Nifedipine for Hypertension and Angina

For patients with hypertension and angina, diltiazem is preferred over nifedipine (Procardia) due to its more favorable heart rate effects, better tolerability, and lower risk of adverse cardiovascular outcomes.

Mechanism of Action and Differences

Both medications are calcium channel blockers (CCBs) but belong to different subclasses:

• Diltiazem: Nondihydropyridine CCB

  • Decreases heart rate and slows AV conduction
  • Provides coronary vasodilation
  • Has negative inotropic effects
  • Reduces peripheral vascular resistance

• Nifedipine (Procardia): Dihydropyridine CCB

  • Produces marked peripheral vasodilation
  • Minimal direct effect on heart rate or contractility
  • May cause reflex tachycardia
  • More potent peripheral vasodilator

Evidence-Based Recommendations

For Hypertension with Angina:

1. First-line therapy:

   • Beta-blockers are first-line for patients with hypertension and angina 1
   • If beta-blockers are contraindicated or cause intolerable side effects, diltiazem is recommended as an alternative 1

2. When to use diltiazem:

   • In patients with continuing or recurring ischemia and contraindications to beta-blockers 1
   • When beta-blockers are not successful or cause unacceptable side effects 1
   • For patients with high heart rate (>70 bpm) 1

3. Cautions with diltiazem:

   • Should not be used in patients with significant LV dysfunction 1
   • Avoid in patients with increased risk for cardiogenic shock 1
   • Avoid in patients with PR interval >0.24 seconds or high-degree AV block without pacemaker 1

Specific Concerns with Nifedipine:

1. Safety concerns:

   • Immediate-release nifedipine should NOT be administered to patients with acute coronary syndromes (Class III: Harm recommendation) 1
   • Short-acting nifedipine should be avoided as it causes reflex sympathetic activation and worsening myocardial ischemia 1
   • Immediate-release nifedipine causes a dose-related increase in mortality in patients with CAD 1

2. Heart rate effects:

   • Nifedipine tends to increase heart rate, which can worsen angina 2, 3
   • Diltiazem decreases elevated baseline heart rate without causing excessive bradycardia 2

Special Populations and Considerations

Heart Rate Considerations:

• If heart rate is elevated (>70 bpm), diltiazem is preferred over nifedipine 1, 2
• Diltiazem has a "regulating effect" - it reduces tachycardia without inducing excessive bradycardia 2

Left Ventricular Dysfunction:

• Both diltiazem and nifedipine should be used with caution in patients with heart failure or LV dysfunction 1
• Beta-blockers are preferred in patients with LV dysfunction and angina 1

Combination Therapy:

• Long-acting dihydropyridines (like amlodipine) are preferred over nondihydropyridines (like diltiazem) when combining with beta-blockers 1
• The combination of beta-blockers and diltiazem should be used with caution due to risk of bradyarrhythmias and heart failure 1

Tolerability:

• Diltiazem appears to be better tolerated than nifedipine 3
• Side effects occur in only 2-10% of patients receiving diltiazem and are generally minor 4

Practical Prescribing Guidance

For diltiazem:

• Starting dose: 30 mg four times daily 5
• Gradually increase dose at 1-2 day intervals 5
• Average optimal dosage: 180-360 mg/day 5
• May be swallowed whole, crushed, or chewed 5

For patients with both hypertension and angina, a treatment algorithm:

1. Start with beta-blockers if not contraindicated
2. If beta-blockers contraindicated or ineffective, use diltiazem
3. If additional BP control needed, add long-acting dihydropyridine CCB or other agents
4. Avoid immediate-release nifedipine in all cases

Common Pitfalls to Avoid

1. Using immediate-release nifedipine without beta-blocker coverage (increases mortality)
2. Combining diltiazem with beta-blockers without careful monitoring (risk of heart block)
3. Using diltiazem in patients with significant LV dysfunction
4. Not adjusting doses carefully in patients with renal or hepatic impairment