The effects of acute changes in renal function on the pharmacokinetics of midazolam during long-term infusion in ICU patients.
This study investigated the pharmacokinetics of midazolam and its main metabolite, 1-hydroxymethylmidazolam glucoronide, during long-term i.v. infusion in 39 mechanically ventilated ICU patients of whom 6 were in acute renal failure (ARF). The mean infusion rate of midazolam was similar (9.4 vs 8.7 mg/h) in the control patients and those with ARF. The renal clearance of 1-hydroxymethylmidazolam glucuronide was much lower in the ARF group than in the control group (3.9 vs 136 ml/min). Consequently, its plasma elimination half-life after discontinuation was also greatly prolonged, but this shouldn't cause very prolonged sedative effects since this metabolite is much less active than the parent drug. However, the half-life of midazolam itself was also significantly longer in patients with ARF than in the control group (13.2 vs 7.6 h). Apparently, this was caused by a combination of a slightly lower total clearance and a higher volume of distribution. Therefore, regular reassessment of the degree of sedation and appropriate adaptation of the infusion rate of midazolam are recommended in ICU patients with ARF.
Driessen
J J
JJ
Department of Anesthesiology, University Hospital, Nijmegen, The Netherlands.
Vree
T B
TB
Guelen
P J
PJ
D058186:Acute Kidney Injury / Q000097:blood*; D016638:Critical Illness; D005260:Female; D005965:Glucuronates / Q000097:blood; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008874:Midazolam / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics*; D008875:Middle Aged; D012121:Respiration, Artificial
D005965:Glucuronates; C040081:1-hydroxymethylmidazolam; D008874:Midazolam