Ketamine kinetics in unmedicated and diazepam-premedicated subjects

Publisher Website
Google Scholar
Abstract
Plasma ketamine concentrations after diazepam and placebo pretreatment were examined in a double-blind, randomized, cross-over study. Eight healthy male subjects received either diazepam or a 0.9% NaCl placebo before ketamine and received the alternate combination 5-24 days later. Ten min before ketamine dosing, diazepam, 0.3 mg/kg, or placebo in equal volume was injected i.v. at a rate not exceeding 5 mg/min. Ketamine, 2.2 mg/kg i.v., was injected over 1 min. For the clinically relevant period for anesthesia (l-30 min), diazepam-ketamine treatment resulted in higher plasma levels at most time points, but diazepam pretreatment did not alter plasma levels of metabolite Kl and pseudometabolite KII nor the 24-h urinary excretion of ketamine, KI, and KII. Ketamine kinetics followed a 3-term exponential decline under both treatment conditions. After placebo-ketamine dosing, plasma t1/2 [half-lives] were as follows: distribution(.pi.t1/2) = 24.1 s, redistribution(.alpha.t1/2) = 4.68 min, and elimination (.beta.t1/2) = 2.17 h. After diazepam-ketamine dosing, t1/2 were: .pi.t1/2 = 25.0 s. .alpha.t1/2 = 6.37min, and .beta.t1/2 = 2.32 h.

This publication has 1 reference indexed in Scilit: