Diltiazem Dosing for Hypertension and Angina
The typical starting dose of diltiazem for hypertension is 30-90 mg orally three to four times daily for immediate-release formulations, or 120-240 mg once daily for extended-release formulations, while for angina, the starting dose is typically lower at 30 mg four times daily for immediate-release or 120 mg once daily for extended-release formulations. 1, 2
Immediate-Release Formulations
- Hypertension: 30-90 mg orally 3-4 times daily (total daily dose: 90-360 mg)
- Angina: 30 mg orally 4 times daily (total daily dose: 120 mg)
Extended-Release Formulations
- Hypertension: 120-240 mg once daily, titrating up to 360 mg once daily
- Angina: 120 mg once daily, titrating up to 240-360 mg once daily
Dosing Considerations
Hypertension
- Higher doses are typically required for hypertension compared to angina 3
- The effective dose range is 240-480 mg/day, with a clear dose-response relationship 4
- Doses below 120 mg/day are generally ineffective for hypertension 3
- Many patients are underdosed, with optimal antihypertensive effects often requiring 360 mg/day 3
Angina
- Lower doses (typically 240 mg/day) are often effective for angina compared to hypertension 3, 5
- Both 240 mg/day and 360 mg/day doses significantly reduce weekly anginal attacks 5
Special Populations
Elderly Patients
- Start with lower doses (e.g., 200 mg once daily of sustained-release formulation) 6
- Titrate cautiously based on response and tolerability
- Monitor for hypotension, bradycardia, and edema
Heart Rate Effects
- Diltiazem decreases elevated heart rates, with greater effects at higher baseline rates 7
- No significant heart rate reduction occurs when baseline heart rate is ≤74 beats/min 7
- This heart rate-regulating effect differentiates diltiazem from dihydropyridine calcium channel blockers
Contraindications and Precautions
- Avoid in patients with:
- Left ventricular dysfunction (LVEF <40%)
- Decompensated heart failure
- AV block greater than first degree
- Sick sinus syndrome
- Cardiogenic shock 2
- Use with caution when combined with beta-blockers due to increased risk of bradycardia and heart block 1, 2
Monitoring
- Blood pressure response
- Heart rate and cardiac conduction
- Signs of fluid retention (edema)
- Symptoms of hypotension or bradycardia
Common Side Effects
- Hypotension
- Dizziness
- Flushing
- Bradycardia
- Edema 1
Remember that diltiazem has both peripheral arterial dilatory effects and prominent AV and sinus node effects, making it particularly useful for patients with both hypertension and angina, especially those with tachycardia.