Influence of the stage of pregnancy on gentamicin disposition in the ewe.

The influence of the state of pregnancy (mid- and end of pregnancy) on the kinetic disposition of gentamicin was determined in the ewe. Kinetic parameters were determined after a single intravenous bolus administration (4 mg/kg). It was shown that the steady state volume of distribution was significantly increased from mid to end of pregnancy (from 0.09 I.kg-1 to 0.194 I.kg-1). Similarly, plasma clearance was increased by about 150% at the end of pregnancy. These modifications must be taken into account in order to adapt the dosage regimen and determine a withdrawal time for gentamicin.