title: Midazolam kinetics in women of two age groups.
abstract: Midazolam kinetics were determined in 11 younger (22 to 30 yr) and 11 older (50 to 60 yr) women to determine age-related differences in the kinetics of this water-soluble benzodiazepine. Midazolam, 0.2 mg/kg, was injected intravenously over 30 sec for induction of anesthesia that was maintained with 67% nitrous oxide in oxygen and intravenous fentanyl doses. There were no differences between the groups with respect to awakening times or plasma concentrations. Midazolam kinetics were described by a three-compartment open mamillary model. The only differences were small increases in the slow and total volumes of distribution in the older women. The kinetics we determined, including the steady-state volume of distribution of 1.23 l/kg and the elimination clearance of 419 ml/min, are in excellent agreement with those reported by others. Our data suggest that midazolam has advantages over other benzodiazepines, not only because of its water solubility and shorter elimination t1/2, but also because of little change in its kinetics with age.
mesh_terms: D000328:Adult; D000375:Aging; D001569:Benzodiazepines / Q000378:metabolism*; D005260:Female; D006801:Humans; D007700:Kinetics; D008874:Midazolam; D008875:Middle Aged
chemical_list: D001569:Benzodiazepines; D008874:Midazolam