An increase in the half-life of pentobarbitone with the administration of halothane in sheep.

The effect of halothane on the half-life of pentobarbitone was studied in sheep. Pentobarbitone was given in a dose of 20 mg/kg and halothane was administered via a mask for periods from 30 min up to 2 hr. Concentrations of pentobarbitone in whole Hood were measured and the half-life determined. In cross-over tests giving pentobarbitone alone, and pentobarbitone and halothane to eight sheep, increases in the half-life with halothane ranging from 4 to 323% (mean 71%) were observed.