Gentamicin-PMMA beads. Pharmacokinetic and nephrotoxicological study

Area of Science:

• Orthopedics
• Pharmacology
• Infectious Diseases

Background:

• Local antibiotic delivery is crucial for treating bone infections.
• Gentamicin-polymethylmethacrylate (PMMA) beads offer a potential method for sustained drug release.
• Understanding the pharmacokinetics and safety of gentamicin-PMMA beads is essential.

Purpose of the Study:

• To evaluate the gentamicin release kinetics from PMMA beads in patients.
• To assess the safety and efficacy of gentamicin-PMMA beads in treating bone infections.
• To determine the systemic absorption and renal excretion of gentamicin delivered via PMMA beads.

Main Methods:

• Five patients undergoing treatment with gentamicin-PMMA beads were monitored.
• Blood and urine samples were collected regularly to measure gentamicin concentrations.
• Renal function (tubular and glomerular) was precisely assessed throughout the treatment period.

Main Results:

• Gentamicin serum concentrations ranged from 0.03-0.4 µg/ml with a renal excretion rate of 3-40 µg/min.
• The in vivo half-life of gentamicin was determined to be 5.7-10 days.
• No evidence of nephrotoxicity was detected despite precise renal function measurements.

Conclusions:

• Gentamicin-PMMA beads function as effective slow-release carriers for local antibiotic therapy.
• The blood-bone barrier appears to protect the body from high local gentamicin concentrations.
• This localized gentamicin delivery method demonstrates a favorable safety profile with no observed nephrotoxicity.