Nicardipine IV Dosing for Severe Hypertension
Start nicardipine at 5 mg/hr IV infusion and titrate by 2.5 mg/hr every 5-15 minutes to a maximum of 15 mg/hr until desired blood pressure reduction is achieved. 1, 2, 3, 4
Initial Dosing Protocol
- Begin with 5 mg/hr as the initial infusion rate through a central line or large peripheral vein 1, 2, 3
- Increase by 2.5 mg/hr increments every 5-15 minutes based on blood pressure response 1, 2, 3
- Maximum dose is 15 mg/hr - this is an absolute ceiling regardless of clinical scenario 2, 3, 4
- Onset of action occurs within 5-15 minutes after starting infusion 3, 5
Blood Pressure Targets
- For severe hypertension (non-stroke), target a 10-15% reduction in mean arterial pressure within the first hour, not normalization 2, 3, 5
- Do not exceed 25% reduction in blood pressure within the first 24 hours to prevent organ hypoperfusion 3, 5
- Precipitous blood pressure drops are dangerous in patients with chronic severe hypertension due to disturbed autoregulation 3, 5
Maintenance Dosing
- Once goal blood pressure is achieved, reduce to 3 mg/hr for maintenance therapy 1, 3, 5
- The average maintenance dose in clinical trials was 8.0 mg/hr for severe hypertension and 3 mg/hr for postoperative hypertension 4
- Sustained blood pressure control is maintained at a constant infusion rate for 4-6 hours 3
Monitoring Requirements
- Monitor blood pressure every 15 minutes during active titration 2, 3
- Once stable at maintenance dose, extend monitoring to every 30 minutes, then hourly as appropriate 2, 3
- Continuously monitor for reflex tachycardia (4% incidence) and flushing 3, 5
Special Considerations for COPD Patients
- Nicardipine is safe in COPD patients as it has predominantly vasodilatory actions with minimal negative inotropic effects 6
- Unlike beta-blockers (such as labetalol), nicardipine does not cause bronchoconstriction and is preferred in patients with reactive airway disease 6, 7
- The intubated status does not alter dosing, but requires vigilant blood pressure monitoring to avoid hypotension 1, 2
When Maximum Dose Fails
- If blood pressure remains uncontrolled at 15 mg/hr, consider switching to sodium nitroprusside for refractory hypertension 1, 2
- Labetalol is an alternative option (10-20 mg IV bolus over 1-2 minutes, repeatable every 10 minutes up to 300 mg maximum), but avoid in COPD due to beta-blocker effects 1, 2
Critical Safety Points
- Offset of action occurs within 30-40 minutes after discontinuation, regardless of infusion duration 3, 5
- Nicardipine is contraindicated in liver failure and requires caution in hepatic impairment 5
- Local phlebitis can develop after 14+ hours of infusion at a single site - rotate IV sites to prevent this complication 8
- Common side effects include headache and flushing, which are generally mild 3, 8