Plasma pharmacokinetics of midazolam in chickens, turkeys, pheasants and bobwhite quail.

In vivo plasma pharmacokinetics of midazolam hydrochloride (5 mg/kg i.v.) were determined in commercially raised broiler chickens, turkeys, ring-necked pheasants and bobwhite quail. Pharmacokinetic profiles of midazolam were similar for all four species, especially with regard to the area under the plasma drug concentration-time curve. Estimates of the half-life of elimination of midazolam were 0.42, 1.45, 1.90, and 9.71 h for turkeys, chickens, bobwhite quail, and pheasant, respectively. This was similar to the major metabolite (1-hydroxymidazolam). Elimination half-lives for 1-hydroxymidazolam were 1.35, 1.86, 1.97, and 13.97 h for turkey, chicken, bobwhite quail and pheasant, respectively. Elimination half-lives for 4-hydroxymidazolam were 0.76, 1.23, 2.85, and 13.82 h for chicken, turkey, pheasant, and bobwhite quail, respectively. In addition to traditional pharmacokinetic approaches to parameter estimation, a bootstrapping technique was employed to attempt to achieve more realistic approximations of the concentrations at later time-points.