The comparative amnestic effects of midazolam, propofol, thiopental, and fentanyl at equisedative concentrations Journal Article


Authors: Veselis, R. A.; Reinsel, R. A.; Feshchenko, V. A.; Wroński, M.
Article Title: The comparative amnestic effects of midazolam, propofol, thiopental, and fentanyl at equisedative concentrations
Abstract: Background: The authors evaluated the effects of midazolam, propofol, thiopental, and fentanyl on volunteer participants memory for words and pictures at equisedative concentrations. Methods: Sixty-seven healthy volunteers were randomized to receive intravenous infusions of midazolam (n- 11), propofol (n=11), thiopental (n=10), fentanyl with ondansetron pretreatment (n=11), ondansetron alone (n=8), or placebo (n=16) in a double- blind design. Three increasing and then two decreasing sedative concentrations were achieved by computer-controlled infusion in each volunteer. Measures of sedation, memory, and drug concentration were obtained at each target concentration. Drug concentrations were normalized to equisedative effects using both Emax and logistic regression methods of pharmacodynamic modeling. The serum concentrations at 50% memory effect (Cp50s) were determined using four different memory end points. The relative potencies compared with midazolam for memory impairment were determined. Results: Equisedative concentrations were midazolam, 64.5 ± 9.4 ng/ml; propofol, 0.7 ± 0.2 μg/ml; thiopental, 2.9 ± 1.0 μg/ml; and fentanyl 0.9 ± 0.2 ng/ml. The Cp50s for 50% loss of memory for words were midazolam, 56 ± 4 ng/ml; propofol, 0.62 ± 0.04 μg/ml; thiopental, 4.5 ± 0.3 μg/ml; and fentanyl, 3.2 ± 0.4 ng/ml. Compared with midazolam, relative potencies (with 95% confidence intervals) were propofol, 0.96 (0.44-1.78); thiopental, 0.76 (0.52-0.94); and fentanyl, 0.34 (0.05-0.76). Large effects on memory were only produced by propofol and midazolam. Conclusions: At equal sedation, propofol produces the same degree of memory impairment as midazolam. Thiopental has mild memory effects whereas fentanyl has none. Ondansetron alone has no sedative or amnesic effects.
Keywords: adult; controlled study; middle aged; clinical trial; drowsiness; controlled clinical trial; randomized controlled trial; midazolam; propofol; sedation; drug potency; ondansetron; drug blood level; high performance liquid chromatography; memory; double blind procedure; double-blind method; amnesia; intravenous drug administration; normal human; fentanyl; hypnotics and sedatives; human experiment; thiopental; radioimmunoassay; humans; human; male; female; priority journal; article; analgesics, opioids: fentanyl; anesthetics, intravenous: midazolam, propofol, thiopental; barbiturates: thiopental; benzodiazepines: midazolam; memory, recall and recognition; modeling, pharmacokinetic- pharmacodynamic
Journal Title: Anesthesiology
Volume: 87
Issue: 4
ISSN: 0003-3022
Publisher: Lippincott Williams & Wilkins  
Date Published: 1997-10-01
Start Page: 749
End Page: 764
Language: English
DOI: 10.1097/00000542-199710000-00007
PUBMED: 9357875
PROVIDER: scopus
DOI/URL:
Notes: Article -- Export Date: 17 March 2017 -- Source: Scopus
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  1. Robert A Veselis
    98 Veselis
  2. Ruth A Reinsel
    78 Reinsel
  3. Marek Wronski
    27 Wronski