Unbound and Periprostatic Adipose Tissue Cefazolin Pharmacokinetics in Robotic-Assisted Radical Prostatectomy

Area of Science:

• Pharmacology
• Clinical Pharmacy
• Surgical Oncology

Background:

• Optimizing cefazolin (CFZ) dosing is crucial for preventing infections during robotic-assisted radical prostatectomy (RARP).
• Understanding CFZ pharmacokinetics in serum and periprostatic tissue is key for effective treatment.

Purpose of the Study:

• To characterize the population pharmacokinetics of unbound cefazolin (CFZ).
• To optimize CFZ dosing regimens for patients undergoing RARP.
• To evaluate target attainment probabilities based on renal function.

Main Methods:

• Population pharmacokinetic analysis using nonlinear mixed-effects modeling.
• Analysis of unbound serum and periprostatic adipose tissue CFZ concentrations.
• Pharmacodynamic target: unbound concentrations > MIC90 against MSSA for >90% of the dosing interval.

Main Results:

• Unbound CFZ systemic clearance correlated with creatinine clearance (CLcr).
• A 1g CFZ infusion achieved target concentrations for >90% of a 3-hour interval in normal renal function.
• In mild renal impairment (CLcr ≤ 80 mL/min), a 5-hour interval maintained target concentrations >90% of the time.

Conclusions:

• Simulations indicate >90% probability of target attainment for up to 5 hours in mild renal impairment.
• Standard additional cefazolin doses may be unnecessary for patients with mild renal impairment.
• Further clinical studies are required to confirm safety and efficacy.