[Is endogenous creatinine clearance a sound basis for estimation of elimination half life of gentamicin?]

The elimination half life of gentamicin after intravenous administration of 80 mg of Refobacin was determined experimentally in 24 patients with normal and variably reduced renal function in the agar diffusion test. Experimentally found elimination half lives were compared to values determined from the creatinine clearance. Although there was good correlation between both parameters, satisfactory agreement between experimentally determined and calculated half life was found only in patients with normal or slightly reduced renal function. With decreasing creatinine clearance the calculated value was constantly bigger than the measured value, and the range of both values increased. Gentamicin treatment in patients with grossly decreased renal function should thus be performed under control of serum levels.