Nicardipine: Mechanism, Uses, and Administration

Nicardipine IV Drip Protocol Concentration

• Mix 20 mg of nicardipine in 80 mL to 100 mL of normal saline (NSS).

• This results in a concentration of 0.2 mg/mL.
  

Infusion Rate

• Administer between 10-70 mL/hour, adjusting based on the patient's blood pressure and clinical condition.

• Titrate by 5 mL/hour every 5-15 minutes to achieve the desired systolic blood pressure (SBP).

Target SBP

• Maintain systolic blood pressure (SBP) ≤ 160 mmHg (adjust further based on specific clinical scenarios or comorbidities).

• In hypertensive emergencies, aim to reduce mean arterial pressure (MAP) by no more than 25% within the first hour, then a gradual reduction over the next 2-6 hours.

  
  

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Mechanism of Action

Nicardipine is a dihydropyridine calcium channel blocker that acts as a vasodilator to lower blood pressure by:

1. Blocking L-type calcium channels: Inhibits calcium influx, primarily in vascular smooth muscle cells.

2. Inducing arterial vasodilation: Reduces systemic vascular resistance (afterload), effectively decreasing blood pressure.

   
   

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Indications

Nicardipine is primarily indicated for:

• Hypertensive emergencies

• Chronic hypertension (oral formulation)

• Angina pectoris: Dilates coronary arteries, improving myocardial oxygen supply.

  
  

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Comparison with Other Calcium Channel Blockers

• Verapamil/Diltiazem: Affect cardiac conduction and heart rate, making them suitable for atrial fibrillation or arrhythmia management.

• Nicardipine: Lacks significant action on the sinoatrial (SA) or atrioventricular (AV) nodes, focusing instead on vascular effects.

  
  

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Preparation and Administration

1. Preparation

   • Mix 20 mg of nicardipine in 80-100 mL NSS (0.2 mg/mL).

   • Ensure thorough mixing of the solution.

2. Administration

   • Start infusion at 10-15 mL/hour.

   • Titrate by 5 mL/hour every 5-15 minutes to achieve the target BP.

   • Maximum rate: 70 mL/hour.
     

Example Dose Calculation

• Initial Rate: 15 mL/hour = 3 mg/hour.

• Adjustment: Increase to 20 mL/hour = 4 mg/hour.

• Max Dose: 70 mL/hour = 14 mg/hour.

  
  

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Monitoring and Safety

1. Blood Pressure and Heart Rate

   • Continuous monitoring is critical.

   • Avoid overshooting target BP, which can result in hypotension.

2. Infusion Site

   • Monitor for signs of phlebitis or extravasation.

     
     

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Common Side Effects

• Hypotension: Excessive vasodilation.

• Reflex tachycardia: Compensatory mechanism for decreased BP.

• Headache, flushing, dizziness: Due to systemic vasodilation.

  
  

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Key Considerations

• Use an IV pump for precise control of infusion rates.

• Individualize BP targets based on patient-specific factors.

• Gradual adjustment is essential to prevent ischemia or other complications.