Diltiazem Dosage and Usage for Hypertension and Angina
For hypertension, diltiazem should be administered at 180-360 mg daily, while for angina, the recommended dosage is 30-90 mg three to four times daily or 120-360 mg once daily in extended-release form. The specific dosing regimen depends on the formulation used and the severity of the condition.
Dosing for Hypertension
Immediate-Release Formulation
- Starting dose: 30 mg four times daily
- Titration: Increase gradually at 1-2 day intervals
- Maintenance dose: 180-360 mg/day divided into 3-4 doses 1
Extended-Release Formulation
- Starting dose: 120-180 mg once daily
- Titration: Increase as needed based on blood pressure response
- Effective dose range: 240-480 mg once daily 2
- Median effective dose: 300 mg/day 3
Research shows that diltiazem is often underdosed for hypertension, with studies demonstrating a clear linear dose-response relationship through the 480-540 mg/day range 4. Higher doses (360 mg/day) are typically required for hypertension compared to angina treatment 4.
Dosing for Angina
Immediate-Release Formulation
- Starting dose: 30 mg four times daily (before meals and at bedtime)
- Titration: Increase gradually at 1-2 day intervals
- Maintenance dose: 180-360 mg/day divided into 3-4 doses 1
Sustained-Release Formulation
Administration Guidelines
- Immediate-release tablets may be swallowed whole, crushed, or chewed 1
- Extended-release formulations should be swallowed whole
- Start with lower doses in elderly patients and those with renal or hepatic impairment 3
- Titrate cautiously in patients with impaired renal or hepatic function 1
Monitoring and Safety Considerations
- Monitor for bradycardia, hypotension, and signs of worsening heart failure 3
- Contraindications:
- Decompensated heart failure
- Severe left ventricular dysfunction
- Pre-excitation syndromes (e.g., WPW syndrome with atrial fibrillation/flutter)
- Sick sinus syndrome 3
- Use with caution in patients with first-degree AV block 3
Combination Therapy
- May be safely coadministered with short- and long-acting nitrates 1
- Use caution when combining with beta-blockers due to increased risk of bradycardia and heart block 3
- If beta-blockers are contraindicated, diltiazem can be substituted, but not if there is LV dysfunction 7
- For uncontrolled angina, a long-acting dihydropyridine CCB can be added to the basic regimen of beta-blocker, ACE inhibitor, and diuretic 7
Specific Recommendations by Condition
For Chronic Stable Angina
- Diltiazem can be effective monotherapy for most patients with chronic stable angina 8
- Doses of up to 360 mg/day may be required in some patients 8
- Major adverse effect of high-dose therapy is mild pedal edema 8
For Hypertension with CAD
- If beta-blockers are contraindicated, diltiazem can be substituted (but not with LV dysfunction) 7
- For patients with hypertension and chronic stable angina, diltiazem can be part of a regimen including beta-blockers, ACE inhibitors/ARBs, and thiazide diuretics 7
For Acute Coronary Syndromes
- In NSTE-ACS with contraindication to beta-blockers, diltiazem can be given as initial therapy in the absence of LV dysfunction, risk for cardiogenic shock, or conduction abnormalities 7
Practical Considerations
- Diltiazem decreases elevated baseline heart rate, with increasing effect at higher initial rates, making it particularly useful in patients with tachycardia 6
- It has minimal effect on heart rates below 74 beats/min, suggesting a regulatory effect 6
- Caution regarding orthostatic hypotension when high-dose diltiazem is combined with nitrate therapy or used in patients with poor left ventricular function 8
By following these dosing guidelines and monitoring parameters, diltiazem can be effectively and safely used to manage both hypertension and angina.