PHARMACOKINETICS OF ACETAMINOPHEN ELIMINATION BY ANEPHRIC PATIENTS

Abstract

The pharmacokinetics of acetaminophen elimination were determined in 5 surgically anephric and 5 physiologically anephric patients on an interdialysis day, and in 3 normal adult volunteers. There was no significant difference in the biologic half-life and no apparent difference in the volume of distribution of acetaminophen [an analgesic, antipyretic] between the 3 groups of subjects but the anephrics, unlike the normal subjects, showed pronounced accumulation of acetaminophen glucuronide and sulfate in plasma. The apparent volume of distribution for conjugated acetaminophen is considerably smaller than that for the unmetabolized drug even though neither acetaminophen nor its glucuronide or sulfate is significantly bound to plasma proteins. The kidneys do not contribute significantly to the elimination of acetaminophen in man. Since acetaminophen is eliminated largely by conjugation with glucuronic acid and sulfate, the kidneys do not contribute significantly to the formation of these metabolites.