What is the protocol for using nicardipine (calcium channel blocker) in a hypertensive emergency?

Nicardipine Protocol for Hypertensive Emergency

For hypertensive emergencies, nicardipine should be initiated at 5 mg/h IV, increased by 2.5 mg/h every 5-15 minutes to a maximum of 15 mg/h until the desired blood pressure reduction is achieved. 1, 2

Initial Assessment and Preparation

• Confirm hypertensive emergency (severe BP elevation with evidence of acute target organ damage)
• Establish IV access, preferably through a central line or large peripheral vein
• Dilute nicardipine if using single-dose vials:
  • Each 25 mg vial must be diluted with 240 mL of compatible IV fluid (e.g., D5W, NS) to create 250 mL of solution at 0.1 mg/mL 2
  • Pre-mixed solutions (0.1 mg/mL or 0.2 mg/mL) do not require dilution 2

Administration Protocol

Dosing and Titration

• Starting dose: 5 mg/h IV infusion 1, 2
• Titration: Increase by 2.5 mg/h every 5-15 minutes 1, 2
  • For gradual BP reduction: increase every 15 minutes
  • For rapid BP reduction: increase every 5 minutes
• Maximum dose: 15 mg/h 1, 2
• If hypotension occurs: discontinue infusion and restart at lower dose (3-5 mg/h) when stabilized 2

Blood Pressure Targets

• General target: Reduce mean arterial pressure by 20-25% within several hours 1
• Condition-specific targets (immediate goals) 1:
  • Aortic dissection: <120 mmHg systolic within first hour
  • Hypertensive encephalopathy: Reduce MAP by 20-25% immediately
  • Acute ischemic stroke with BP >220/120 mmHg: Reduce MAP by 15% within first hour
  • Acute hemorrhagic stroke with BP >180 mmHg: 130-180 mmHg systolic immediately
  • Acute coronary event or cardiogenic pulmonary edema: <140 mmHg systolic immediately

Monitoring

• Continuous BP and heart rate monitoring during infusion and after discontinuation
• Monitor for signs of hypotension, tachycardia, or too rapid reduction in BP 2
• For patients receiving thrombolysis, maintain BP <180/105 mmHg 1

Administration Considerations

Infusion Site Management

• Change infusion site every 12 hours if administered via peripheral vein to minimize risk of phlebitis 1, 2
• Avoid small veins such as those on the dorsum of the hand or wrist 2
• Avoid intraarterial administration or extravasation 2

Compatibility

• Compatible with: D5W, NS, D5NS, D5 with 0.45% NaCl 2
• Not compatible with: Sodium Bicarbonate 5% or Lactated Ringer's 2

Transition to Oral Therapy

• Begin oral antihypertensives 1 hour before discontinuing IV nicardipine to prevent rebound hypertension 1
• When substituting for oral nicardipine, use appropriate IV infusion rate based on oral dose 2
• Transfer to oral medication as soon as clinical condition permits 2

Special Considerations

• Closely monitor patients with:
  • Angina
  • Congestive heart failure
  • Impaired hepatic or renal function
  • Portal hypertension
  • Pheochromocytoma 2
• Nicardipine is not a beta-blocker; if withdrawing beta-blockers, do so gradually 2
• Most common adverse effects: headache (13%), hypotension (5%), tachycardia (4%), and nausea/vomiting (4%) 2

By following this protocol, nicardipine can effectively manage hypertensive emergencies with rapid onset of action and predictable dose-response relationship, allowing for precise blood pressure control.