Clinical pharmacokinetics of long-term infusion of midazolam in critically ill patients--preliminary results.

Seven intensive care patients were sedated with prolonged infusion of midazolam. One patient received a continuous infusion of midazolam for the treatment of status epilepticus. A bolus injection of 5 mg was administered, followed by infusion of 4-14 mg/hour depending on the required level of sedation. The length of infusion varied between 80 and 360 hours. The plasma concentrations of the midazolam during infusion were between 500-1000 ng/ml. All the patients were adequately sedated. The plasma elimination half-life of midazolam and its main metabolite, 1-OH-midazolam glucuronide, after stopping the infusion varied from 4-12 hours.