What is the recommended protocol for a nicardipine drip in a patient with severe hypertension?

Nicardipine Drip Protocol for Severe Hypertension (180/100)

Start nicardipine at 5 mg/hr IV infusion and titrate by 2.5 mg/hr every 5-15 minutes up to a maximum of 15 mg/hr, targeting a 10-15% reduction in blood pressure rather than normalization to avoid organ hypoperfusion. 1, 2, 3

Initial Setup and Administration

• Administer through a central line or large peripheral vein at a concentration of 0.1 mg/mL 4
• Change the infusion site every 12 hours if using a peripheral vein to prevent phlebitis 4
• Single dose vials (25 mg) must be diluted with 240 mL of compatible IV fluid (D5W, NS, or D5NS) to achieve 0.1 mg/mL concentration 4

Titration Protocol

Standard Approach (Gradual Reduction)

• Begin at 5 mg/hr IV infusion 1, 2, 3
• Increase by 2.5 mg/hr every 15 minutes for gradual blood pressure reduction 3
• Maximum dose is 15 mg/hr 1, 2, 3

Rapid Reduction (When Clinically Indicated)

• Increase by 2.5 mg/hr every 5 minutes for more urgent situations 1, 3
• Onset of action occurs within 5-15 minutes 1
• Therapeutic response typically achieved within 45 minutes at higher infusion rates 4, 5

Blood Pressure Targets

Critical: Do not normalize blood pressure to 120/80 mmHg in acute severe hypertension 2

• General severe hypertension: Target 10-15% reduction from baseline (approximately 160-165/85-90 mmHg for your patient with 180/100) 1, 2, 3
• Pre-thrombolytic stroke: Strict target <185/110 mmHg before rtPA administration 1, 2, 3
• Post-thrombolytic stroke: Maintain <180/105 mmHg 3

Monitoring Requirements

During Active Titration

• Check blood pressure every 15 minutes while adjusting the infusion rate 2, 3
• Monitor heart rate continuously (expect increase of approximately 10 beats/minute) 5, 6

After Achieving Target

• Every 15 minutes for the first 2 hours 1, 3
• Every 30 minutes for the next 6 hours 1, 3
• Every hour for the subsequent 16 hours 1, 3

Maintenance Dosing

• Once desired blood pressure is achieved, reduce to 3 mg/hr as maintenance dose 1
• Average maintenance dose in clinical trials was 3-8 mg/hr depending on clinical scenario 4, 7
• Sustained blood pressure control occurs at constant infusion rates for 4-6 hours 1

Downtitration and Transition

When Blood Pressure Stabilizes

• Decrease infusion rate by 2.5 mg/hr every 5-15 minutes while monitoring continuously 1
• Find the lowest effective maintenance rate that keeps blood pressure at target 1

Transitioning to Oral Therapy

• Administer first oral dose 1 hour before discontinuing IV infusion 3
• Equivalent dosing: Oral 30 mg TID ≈ IV 1.2 mg/hr; Oral 40 mg TID ≈ IV 2.2 mg/hr 1, 3
• Offset of action occurs within 30-40 minutes after discontinuation 1, 4

Critical Safety Considerations

Common Pitfalls to Avoid

• Do not reduce blood pressure by more than 25% in the first 24 hours to prevent organ hypoperfusion 1, 2
• Do not aim for "normal" blood pressure (120/80) in acute severe hypertension 2
• Do not infuse through the same line as sodium bicarbonate or lactated Ringer's (incompatible) 4

Special Populations

• Stroke patients: Exercise extreme caution to avoid systemic hypotension as cerebral autoregulation is impaired 1, 3
• Ischemic stroke (first 5-7 days): Excessive blood pressure reduction is associated with adverse neurological outcomes 1
• Immunosuppressed patients: Monitor cyclosporine and tacrolimus levels closely as nicardipine inhibits CYP3A4 1, 3

Side Effects

• Flushing and headache are common but typically mild 1, 5
• Local phlebitis may develop after 14+ hours at a single peripheral site (change site every 12 hours) 4, 5
• Reflex tachycardia of approximately 10 beats/minute is expected 5, 6

Alternative Agent

• If nicardipine is unavailable or contraindicated, consider labetalol 10-20 mg IV over 1-2 minutes, repeatable or doubled every 10 minutes up to 300 mg maximum 2