The pharmacokinetics of minaxolone, a new steroidal anesthetic agent, were derived after continuous i.v. infusion and bolus administration in the chronically catheterized sheep. There was a linear relationship between the steady-state blood concentration after continuous i.v. infusion rate used, indicating that minaxolone pharmacokinetics were linear. Further experimental evidence in support of this finding was the lack of dose dependence in any pharmacokinetic parameter following bolus doses through the clinical range of 12.5-100 mg. Minaxolone had a high total body clearance between 3-4 l/min and a terminal half-life between 10-20 min. Renal excretion of unchanged minaxolone was < 1%. Organ clearance studies indicated that minaxolone was totally extracted during passage through the liver but negligible extraction occurred during passage through the kidney and lung.