Enzyme induction effects in the human metabolism of butobarbitone

Summary  The human metabolism of butobarbitone has been studied in two healthy volunteers at two dose levels, and using sequential dosing. The results are examined graphically, and shown to be consistent with first order processes, provided that due allowance is made for the effects of liver induction. Induction reaches a maximum 3–4 days after a single therapeutic dose; but is still rising after about 10 days, when repetitive doses are given. There is no evidence for saturable kinetics, in the therapeutic dose ranges used in this study.