DOSE REGIMEN OF KANAMYCIN AND GENTAMICIN

Abstract

Abstract. The half‐lives of kanamycin and gentamicin have been determined in 74 and 49 patients, respectively. In patients with normal serum creatinine values the kanamycin T ½ varied from 90 to 538 min and the gentamicin T ½ from 40 to 370 min, and in both cases an inversely proportional relationship with creatinine clearance was found. The half‐lives of both drugs increased with advancing age, reflecting the age‐dependent decrease in endogenous creatinine clearance which takes place with unaltered serum creatinine values. This finding invalidates many calculations of drug half‐lives based solely upon serum creatinine values. Using a previously described nomogram it is possible to evaluate a patient's creatinine clearance if the age, sex, weight and serum creatinine are known. Calculations of kanamycin and gentamicin half‐lives based upon evaluation of creatinine clearance from the nomogram are compared with the measured half‐lives. Dose regimens for kanamycin and gentamicin are suggested.