Recommended Dosing of Diltiazem for Hypertension
For hypertension treatment, diltiazem should be initiated at 120 mg daily and titrated up to 360 mg daily as a maximum maintenance dose, with higher doses (240-360 mg) typically required for optimal blood pressure control. 1
Initial Dosing and Titration
- Start with 120 mg daily, using either divided doses for immediate-release formulations or a single daily dose for extended-release formulations 1
- Titrate cautiously and progressively over several weeks to reach effective blood pressure control 2
- For extended-release formulations, initial doses of 180 mg once daily can be used, with subsequent increases based on response 3
Effective Dosing Range
- The therapeutic range for hypertension is typically 240-360 mg daily 1, 4
- Lower doses (90-120 mg/day) are often subtherapeutic for hypertension management 4
- Studies demonstrate a clear linear dose-response relationship between diltiazem dose and blood pressure lowering through the 480-540 mg/day range 4
Formulation Considerations
- Extended-release formulations allow for once-daily dosing, improving adherence 3, 5
- Once-daily diltiazem CD and twice-daily diltiazem SR both effectively control blood pressure over a 24-hour period 5
- Doses ≥240 mg/day provide trough drug blood levels within the therapeutic range (≥40 ng/mL) 3
Efficacy Data
- Doses of 240 mg and above significantly decrease clinic diastolic blood pressure, while higher doses (360-540 mg) are more effective for both systolic and diastolic blood pressure control 6
- Ambulatory blood pressure monitoring shows that doses of 360 mg and 540 mg provide significant 24-hour blood pressure reduction 6
- Trough/peak ratios for systolic and diastolic blood pressures are 50% or higher at dose levels of 240 mg and above 6
Safety and Monitoring
- Monitor blood pressure and heart rate regularly during dose titration 1
- Watch for common adverse effects including hypotension, bradycardia, peripheral edema, and constipation 1, 2
- Use caution in patients with bradycardia, as this may be dose-limiting 2
Special Considerations
- Avoid diltiazem in patients with AV block greater than first degree, SA node dysfunction without pacemaker, hypotension, decompensated heart failure, or severe LV dysfunction 1
- Use caution when combining with beta-blockers due to risk of significant bradyarrhythmias 1
- For patients with relative tachycardia, diltiazem may be preferred over other calcium channel blockers like nifedipine 2
Common Pitfalls
- Underdosing is common in clinical practice, with many prescriptions written for subtherapeutic doses (180-240 mg daily) 4
- Failure to titrate to effective doses may result in inadequate blood pressure control 4
- Adding diuretics may help manage peripheral edema side effects 2
For optimal hypertension management, diltiazem doses should be titrated to the 240-360 mg daily range for most patients, with careful monitoring for efficacy and tolerability.