Infusion model for fentanyl based on pharmacokinetic analysis

Area of Science:

• Pharmacology
• Anesthesiology
• Pharmacokinetics

Background:

• Fentanyl is a potent opioid analgesic used in anesthesia.
• Achieving steady-state plasma concentrations of fentanyl is crucial for effective and safe anesthesia.
• Optimizing intravenous (i.v.) infusion schemes can improve drug delivery and patient outcomes.

Purpose of the Study:

• To calculate pharmacokinetic parameters of fentanyl after bolus injection.
• To develop an i.v. infusion scheme for sustained analgesia during surgery.
• To validate a pharmacokinetic model for total i.v. anesthesia.

Main Methods:

• Pharmacokinetic analysis of fentanyl following bolus injection.
• Development of a two-stage infusion rate model for total i.v. anesthesia.
• Monitoring plasma concentrations during surgical anesthesia.

Main Results:

• Rapid initial decrease in serum fentanyl concentration (10 min) due to peripheral distribution.
• Slower elimination phase with a half-life of approximately 2 hours.
• Total volume of distribution (80 L) and plasma clearance (500 mL/min) were determined.
• Predicted steady-state plasma concentrations aligned with actual concentrations during anesthesia, ensuring continuous analgesia.

Conclusions:

• Fentanyl pharmacokinetic calculations allow for effective i.v. infusion schemes.
• The developed model ensures steady plasma concentrations and continuous analgesia throughout surgery.
• This approach is validated for total i.v. anesthesia, improving drug administration and patient comfort.