Midazolam pharmacokinetics and electroencephalographic changes in eight Chinese men

Eight Chinese healthy male volunteers aged 27 +/- s 4 a were injected i.v. midazolam (Mid) 15 mg. Blood samples were collected at 0, 2, 5, 7, 10, 20, 30, 45, 60, 90, 120, 180, and 240 min. A HPLC method was established for determining the Mid concentrations in serum. The concentration-time data was fitted with biexponential curve. Pharmacokinetic parameters were: T1/2 alpha = 6.8 +2- 2.5 min, T1/2 beta = 118 +/- 27 min, Vc = 25 +/- 7 L, Cl = 393 +/- 79 ml.min-1, Vdss = 59 +/- 13 L, AUC0-infinity = 39.6 +/- 8.6 g.min.L-1. The electroencephalogram (EEG) showed a decrease in alpha activity and an increase in beta activity. The EEG pattern reverted toward baseline after 2-3 h. Pharmacokinetic and EEG findings suggest that Mid is a preferable anesthesia inducing agent.