Changes in erythromycin pharmacokinetics induced by renal failure.

Area of Science:

• Pharmacology
• Nephrology
• Toxicology

Background:

• Erythromycin ototoxicity is associated with renal insufficiency.
• Understanding erythromycin pharmacokinetics in chronic kidney disease is crucial for patient safety.

Purpose of the Study:

• To assess the pharmacokinetics of erythromycin ethylsuccinate in chronic uremic patients undergoing maintenance hemodialysis.
• To compare these pharmacokinetic parameters with those of normal subjects.

Main Methods:

• A single oral dose of 1 gram of erythromycin ethylsuccinate was administered to two groups of 8 patients each (interdialytic day and post-hemodialysis) and 8 healthy controls.
• Serum concentrations were measured over time to determine peak serum concentration, biological half-life, maximum serum concentration, area under the serum concentration time-curve, and apparent oral clearance.

Main Results:

• Peak serum concentrations and biological half-lives were similar between uremic patients and controls.
• Uremic patients exhibited higher maximum serum concentrations and areas under the serum concentration time-curve compared to controls.
• Apparent oral clearance was lower in uremic patients, suggesting enhanced bioavailability.

Conclusions:

• Pharmacokinetic changes in chronic renal failure indicate enhanced erythromycin bioavailability.
• This enhanced bioavailability may increase the risk of erythromycin-induced ototoxicity in uremic patients.