PHARMACOKINETICS OF PENTOBARBITAL IN THE DOG

  • 1 January 1983
    • journal article
    • research article
    • Vol. 225  (2) , 355-360
Abstract
The pharmacokinetics of pentobarbital were studied after i.v. administration of a 30 mg/kg dose to 5 dogs. Pentobarbital plasma concentrations were measured with a new gas chromatographic method, utilizing on-column methylation of pentobarbital and as a butabarbital internal standard. The kinetics of pentobarbital distribution and elimination were analyzed with a 3-compartment open mammillary model. The elimination-phase half-life of pentobarbital was 8.2 .+-. 2.2 h. The steady-state volume of pentobarbital distribution was 1.08 .+-. 0.21 l/kg and the elimination clearance was 0.0013 .+-. 0.0004 l/min .cntdot. kg. Threshold pentobarbital concentrations required to suppress the corneal reflex and withdrawal response to pain were 26.4 .+-. 4.6 and 23.0 .+-. 2.9 .mu.g/ml, respectively. These results should facilitate the design of i.v. anesthetic regimens with pentobarbital.