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Hirjak D, Fricchione G, Wolf RC, Northoff G. Lorazepam in catatonia - Past, present and future of a clinical success story. Schizophr Res 2024; 263:27-34. [PMID: 36805317 DOI: 10.1016/j.schres.2023.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/20/2023]
Abstract
The effect of lorazepam in the treatment of catatonia is outstanding and almost immediate. Clinicians are familiar with its effects: mute patients can speak again, akinetic patients can move again and patients with negativism can eat and drink again within usually a short duration of about 10 min to 1-2 h. Fear is often gone after lorazepam administration. While not always effective, the introduction of lorazepam into clinical practice represented a breakthrough and was often life-saving for many patients suffering from catatonia. It is rare to observe such rapid therapeutic effects in other domains of psychiatry. In this narrative review we will briefly look at the past, present and future of lorazepam in the treatment of catatonia. It is gratifying to reflect on the fact that clinicians using the age-old medical practice of observation and empirical treatment succeeded in advancing the management of catatonia 40 years ago. The present evidence shows that the clinical effect of lorazepam in catatonia treatment is excellent and more or less immediate although it remains to be explicitly tested against other substances such as diazepam, zolpidem, clozapine, quetiapine, amantadine, memantine, valproate and dantrolene in randomized clinical trials. In addition, future studies need to answer the question how long lorazepam should be given to patients with catatonia, months or even years? This narrative review promotes the rapid use of lorazepam in the treatment of acute catatonic patients and stipulates further scientific examination of its often impressive clinical effects.
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Affiliation(s)
- Dusan Hirjak
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
| | - Gregory Fricchione
- Benson-Henry Institute for Mind Body Medicine, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Robert Christian Wolf
- Center for Psychosocial Medicine, Department of General Psychiatry, University of Heidelberg, Heidelberg, Germany
| | - Georg Northoff
- Mind, Brain Imaging and Neuroethics Research Unit, The Royal's Institute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada
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King C, Lewinsohn A, Keeliher C, McLachlan S, Sherrin J, Khan-Cheema H, Sherren P. Cardiovascular complications of prehospital emergency anaesthesia in patients with return of spontaneous circulation following medical cardiac arrest: a retrospective comparison of ketamine-based and midazolam-based induction protocols. Emerg Med J 2021; 39:672-678. [PMID: 34588175 DOI: 10.1136/emermed-2020-210531] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 09/19/2021] [Indexed: 11/04/2022]
Abstract
BACKGROUND Hypotension following intubation and return of spontaneous circulation (ROSC) after cardiac arrest is associated with poorer patient outcomes. In patients with a sustained ROSC requiring emergency anaesthesia, there is limited evidence to guide anaesthetic practice. At the Essex & Herts Air Ambulance Trust, a UK-based helicopter emergency medical service, we assessed the relative haemodynamic stability of two different induction agents for post-cardiac arrest medical patients requiring prehospital emergency anaesthesia (PHEA). METHODS We performed a retrospective database review over a 5-year period between December 2014 and December 2019 comparing ketamine-based and midazolam-based anaesthesia in this patient cohort. Our primary outcome was clinically significant hypotension within 30 min of PHEA, defined as a new systolic BP less than 90 mm Hg, or a 10% drop if less than 90 mm Hg before induction. RESULTS One hundred ninety-eight patients met inclusion criteria. Forty-eight patients received a ketamine-based induction, median dose (IQR) 1.00 (1.00-1.55) mg/kg, and a 150 midazolam-based regime, median dose 0.03 (0.02-0.04) mg/kg. Hypotension occurred in 54.2% of the ketamine group and 50.7% of the midazolam group (p=0.673). Mean maximal HRs within 30 min of PHEA were 119 beats/min and 122 beats/min, respectively (p=0.523). A shock index greater than 1.0 beats/min/mm Hg and age greater than 70 years were both associated with post-PHEA hypotension with ORs 1.96 (CI 1.02 to 3.71) and 1.99 (CI 1.01 to 3.90), respectively. Adverse event rates did not significantly differ between groups. CONCLUSION PHEA following a medical cardiac arrest is associated with potentially significant cardiovascular derangements when measured up to 30 min after induction of anaesthesia. There was no demonstrable difference in post-induction hypotension between ketamine-based and midazolam-based PHEA. Choice of induction agent alone is insufficient to mitigate haemodynamic disturbance, and alternative strategies should be used to address this.
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Affiliation(s)
| | | | | | - Sarah McLachlan
- Research Department, Essex & Herts Air Ambulance, Essex, UK.,Department of Allied Health and Medicine, Anglia Ruskin University, Chelmsford, UK
| | - James Sherrin
- University College London Medical School, London, UK
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Srinivas N, Maffuid K, Kashuba ADM. Clinical Pharmacokinetics and Pharmacodynamics of Drugs in the Central Nervous System. Clin Pharmacokinet 2018; 57:1059-1074. [PMID: 29464550 PMCID: PMC6062484 DOI: 10.1007/s40262-018-0632-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Despite contributing significantly to the burden of global disease, the translation of new treatment strategies for diseases of the central nervous system (CNS) from animals to humans remains challenging, with a high attrition rate in the development of CNS drugs. The failure of clinical trials for CNS therapies can be partially explained by factors related to pharmacokinetics/pharmacodynamics (PK/PD), such as lack of efficacy or improper selection of the initial dosage. A focused assessment is needed for CNS-acting drugs in first-in-human studies to identify the differences in PK/PD from animal models, as well as to choose the appropriate dose. In this review, we summarize the available literature from human studies on the PK and PD in brain tissue, cerebrospinal fluid, and interstitial fluid for drugs used in the treatment of psychosis, Alzheimer's disease and neuro-HIV, and address critical questions in the field. We also explore newer methods to characterize PK/PD relationships that may lead to more efficient dose selection in CNS drug development.
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Affiliation(s)
- Nithya Srinivas
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, 1094 Genetic Medicine Building, CB# 7361, 120 Mason Farm Road, Chapel Hill, NC, 27599, USA
| | - Kaitlyn Maffuid
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, 1094 Genetic Medicine Building, CB# 7361, 120 Mason Farm Road, Chapel Hill, NC, 27599, USA
| | - Angela D M Kashuba
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina, 1094 Genetic Medicine Building, CB# 7361, 120 Mason Farm Road, Chapel Hill, NC, 27599, USA.
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Nourbakhsh M, Miller A, Gofton J, Jones G, Adeagbo B. Cannabinoid Hyperemesis Syndrome: Reports of Fatal Cases. J Forensic Sci 2018; 64:270-274. [DOI: 10.1111/1556-4029.13819] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/17/2018] [Accepted: 04/23/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Mahra Nourbakhsh
- Department of Pathology and Laboratory Medicine Foothills Medical Center Cumming School of Medicine University of Calgary McCaig Tower 7542, 1403 29 Street NW Calgary AB T2N 2T9 Canada
| | - Angela Miller
- Department of Pathology and Laboratory Medicine Foothills Medical Center Cumming School of Medicine University of Calgary McCaig Tower 7542, 1403 29 Street NW Calgary AB T2N 2T9 Canada
- Department of Laboratory Medicine and Pathology 4B1.18 Walter Mackenzie Centre University of Alberta 8440‐112 Street Edmonton AB T6G 2B7 Canada
- Office of the Chief Medical Examiner 4070 Bowness Rd NW Calgary AB T3B 3R7 Canada
| | - Jeff Gofton
- Office of the Chief Medical Examiner 4070 Bowness Rd NW Calgary AB T3B 3R7 Canada
- Office of the Chief Medical Examiner 400 East Jackson Street Richmond VA 23219‐3694
| | - Graham Jones
- Department of Laboratory Medicine and Pathology 4B1.18 Walter Mackenzie Centre University of Alberta 8440‐112 Street Edmonton AB T6G 2B7 Canada
- Office of the Chief Medical Examiner 4070 Bowness Rd NW Calgary AB T3B 3R7 Canada
| | - Bamidele Adeagbo
- Department of Pathology and Laboratory Medicine Foothills Medical Center Cumming School of Medicine University of Calgary McCaig Tower 7542, 1403 29 Street NW Calgary AB T2N 2T9 Canada
- Department of Laboratory Medicine and Pathology 4B1.18 Walter Mackenzie Centre University of Alberta 8440‐112 Street Edmonton AB T6G 2B7 Canada
- Office of the Chief Medical Examiner 4070 Bowness Rd NW Calgary AB T3B 3R7 Canada
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Wilson FJ, Leiser SC, Ivarsson M, Christensen SR, Bastlund JF. Can pharmaco-electroencephalography help improve survival of central nervous system drugs in early clinical development? Drug Discov Today 2013; 19:282-8. [PMID: 23954252 DOI: 10.1016/j.drudis.2013.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 07/03/2013] [Accepted: 08/01/2013] [Indexed: 11/25/2022]
Abstract
Pharmaco-electroencephalography has significant yet unrealised promise as a translatable intermediate biomarker of central pharmacodynamic activity that could help reduce Phase 2 attrition in the development of central nervous system drugs. In an effort to understand its true potential, a framework for decision-making was proposed and the utility of pharmaco-electroencephalography was assessed through several case studies. A key finding was that lack of standardisation reduces the value of data pooling and meta-analyses and renders assessment of translatability difficult, limiting utility in all but simple cases. Pre-competitive collaboration is essential both to improving understanding of translation and developing modern signal processing techniques.
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Affiliation(s)
- Frederick J Wilson
- Medical Imaging and Physiological Measurements Consultant, Canterbury, Kent, UK.
| | - Steven C Leiser
- Lundbeck Research USA, Inc., 215 College Road, Paramus, NJ 07652, USA
| | - Magnus Ivarsson
- Science for Life Laboratory (SciLifeLab Stockholm), AstraZeneca Research and Development, Tomtebodavägen 23, S-171 65 Solna, Sweden
| | - Søren R Christensen
- Clinical Pharmacology, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
| | - Jesper F Bastlund
- Synaptic Transmission, H. Lundbeck A/S, Ottiliavej 9, DK-2500 Valby, Denmark
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Berry JD, Shefner JM, Conwit R, Schoenfeld D, Keroack M, Felsenstein D, Krivickas L, David WS, Vriesendorp F, Pestronk A, Caress JB, Katz J, Simpson E, Rosenfeld J, Pascuzzi R, Glass J, Rezania K, Rothstein JD, Greenblatt DJ, Cudkowicz ME. Design and initial results of a multi-phase randomized trial of ceftriaxone in amyotrophic lateral sclerosis. PLoS One 2013; 8:e61177. [PMID: 23613806 PMCID: PMC3629222 DOI: 10.1371/journal.pone.0061177] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 02/27/2013] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES Ceftriaxone increases expression of the astrocytic glutamate transporter, EAAT2, which might protect from glutamate-mediated excitotoxicity. A trial using a novel three stage nonstop design, incorporating Phases I-III, tested ceftriaxone in ALS. Stage 1 determined the cerebrospinal fluid pharmacokinetics of ceftriaxone in subjects with ALS. Stage 2 evaluated safety and tolerability for 20-weeks. Analysis of the pharmacokinetics, tolerability, and safety was used to determine the ceftriaxone dosage for Stage 3 efficacy testing. METHODS In Stage 1, 66 subjects at ten clinical sites were enrolled and randomized equally into three study groups receiving intravenous placebo, ceftriaxone 2 grams daily or ceftriaxone 4 grams daily divided BID. Participants provided serum and cerebrospinal fluid for pharmacokinetic analysis on study day 7. Participants continued their assigned treatment in Stage 2. The Data and Safety Monitoring Board (DSMB) reviewed the data after the last participants completed 20 weeks on study drug. RESULTS Stage 1 analysis revealed linear pharmacokinetics, and CSF trough levels for both dosage levels exceeding the pre-specified target trough level of 1 µM (0.55 µg/mL). Tolerability (Stages 1 and 2) results showed that ceftriaxone at dosages up to 4 grams/day was well tolerated at 20 weeks. Biliary adverse events were more common with ceftriaxone but not dose-dependent and improved with ursodeoxycholic (ursodiol) therapy. CONCLUSIONS The goals of Stages 1 and 2 of the ceftriaxone trial were successfully achieved. Based on the pre-specified decision rules, the DSMB recommended the use of ceftriaxone 4 g/d (divided BID) for Stage 3, which recently closed. TRIAL REGISTRATION ClinicalTrials.gov NCT00349622.
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Affiliation(s)
- James D. Berry
- Neurology Clinical Research Institute, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jeremy M. Shefner
- Department of NeurologyState University of New York Upstate Medical University, Syracuse, New York, United States of America
| | - Robin Conwit
- National Institute of Neurologic Disorders and Stroke, Bethesda, Maryland, United States of America
| | - David Schoenfeld
- Department of Biostatistics, Massachusetts General Hospital, Boston, Massachusetts, United States of America
| | - Myles Keroack
- Department of Gastroenterology, Marshfield Clinic, Eau Claire, Wisconsin, United States of America
| | - Donna Felsenstein
- Infectious Disease Unit/Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lisa Krivickas
- Neurology Clinical Research Institute, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - William S. David
- Neurology Clinical Research Institute, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Francine Vriesendorp
- Department of NeurologyState University of New York Upstate Medical University, Syracuse, New York, United States of America
| | - Alan Pestronk
- Department of Neurology, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - James B. Caress
- Department of Neurology, Wake Forest University, Winston-Salem, North Carolina, United States of America
| | - Jonathan Katz
- Department of Neurology, California Pacific Medical Center, San Francisco, California, United States of America
| | - Ericka Simpson
- Department of Neurology, Methodist Neurological Institute, Houston, Texas, United States of America
| | - Jeffrey Rosenfeld
- Department of Neurology, University of California San Francisco Fresno, Neuroscience Institute, Fresno, California, United States of America
| | - Robert Pascuzzi
- Department of Neurology, Indiana University, Indianapolis, Indiana, United States of America
| | - Jonathan Glass
- Department of Neurology, Emory University, Atlanta, Georgia, United States of America
| | - Kourosh Rezania
- Department of Neurology, University of Chicago, Chicago, Illinois, United States of America
| | - Jeffrey D. Rothstein
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - David J. Greenblatt
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Merit E. Cudkowicz
- Neurology Clinical Research Institute, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
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Harvey AT, Flockhart D, Gorski JC, Greenblatt DJ, Burke M, Werder S, Preskorn SH. Intramuscular Haloperidol or Lorazepam and QT Intervals in Schizophrenia. J Clin Pharmacol 2013; 44:1173-84. [PMID: 15342619 DOI: 10.1177/0091270004267807] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objective of this study was to estimate the effects of intramuscular haloperidol and lorazepam on the QT interval in volunteers with schizophrenia. Intramuscular haloperidol and intramuscular lorazepam are standard treatments in the acute management of agitation and aggression. Although prolongation of the QT interval and sequelae, including torsade de pointes and death, have been reported for haloperidol (but not lorazepam), formal studies have been lacking. Volunteers with schizophrenia (n = 12) were administered a single intramuscular injection of 7.5 mg haloperidol or 4 mg lorazepam in a blinded, randomized, placebo-controlled crossover design. Serial EKGs and concurrent blood samples were obtained over 6 hours following each injection. Changes in the QT interval were evaluated, as were plasma drug and prolactin concentrations. Haloperidol injection increased the heart rate-corrected QT interval an average of 5.1 msec using Bazett's correction (QTb 90% confidence interval [CI]: 0.3, 9.8), 3.6 msec using Fridericia's correction (QTf 90% CI: 0.02, 7.2), and 4.2 msec using an empirically derived "baseline correction" (QT(ii) 90% CI: 0.3, 8.0). Effects of lorazepam on QT were nullified by correction for the heart rate elevation (QTb 3.8 msec, 90% CI: 0.6, 7.1; QTf 0.0 msec, 90% CI: -3.2, 3.4; QTii -2.3 msec, 90% CI: -6.6, 2.0). An association between QT prolongation and occurrence of extrapyramidal symptoms was observed. On average, intramuscular haloperidol led to minimal prolongation of the QT interval. This propensity is of theoretical concern in individuals with risk factors for torsade de pointes but seems unlikely to be a problem in the vast majority of patients.
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Affiliation(s)
- Anne T Harvey
- Psychiatric Research, Institute, Wichita, KS 67214-2878
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Clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit. Crit Care Med 2013; 41:263-306. [PMID: 23269131 DOI: 10.1097/ccm.0b013e3182783b72] [Citation(s) in RCA: 2284] [Impact Index Per Article: 207.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To revise the "Clinical Practice Guidelines for the Sustained Use of Sedatives and Analgesics in the Critically Ill Adult" published in Critical Care Medicine in 2002. METHODS The American College of Critical Care Medicine assembled a 20-person, multidisciplinary, multi-institutional task force with expertise in guideline development, pain, agitation and sedation, delirium management, and associated outcomes in adult critically ill patients. The task force, divided into four subcommittees, collaborated over 6 yr in person, via teleconferences, and via electronic communication. Subcommittees were responsible for developing relevant clinical questions, using the Grading of Recommendations Assessment, Development and Evaluation method (http://www.gradeworkinggroup.org) to review, evaluate, and summarize the literature, and to develop clinical statements (descriptive) and recommendations (actionable). With the help of a professional librarian and Refworks database software, they developed a Web-based electronic database of over 19,000 references extracted from eight clinical search engines, related to pain and analgesia, agitation and sedation, delirium, and related clinical outcomes in adult ICU patients. The group also used psychometric analyses to evaluate and compare pain, agitation/sedation, and delirium assessment tools. All task force members were allowed to review the literature supporting each statement and recommendation and provided feedback to the subcommittees. Group consensus was achieved for all statements and recommendations using the nominal group technique and the modified Delphi method, with anonymous voting by all task force members using E-Survey (http://www.esurvey.com). All voting was completed in December 2010. Relevant studies published after this date and prior to publication of these guidelines were referenced in the text. The quality of evidence for each statement and recommendation was ranked as high (A), moderate (B), or low/very low (C). The strength of recommendations was ranked as strong (1) or weak (2), and either in favor of (+) or against (-) an intervention. A strong recommendation (either for or against) indicated that the intervention's desirable effects either clearly outweighed its undesirable effects (risks, burdens, and costs) or it did not. For all strong recommendations, the phrase "We recommend …" is used throughout. A weak recommendation, either for or against an intervention, indicated that the trade-off between desirable and undesirable effects was less clear. For all weak recommendations, the phrase "We suggest …" is used throughout. In the absence of sufficient evidence, or when group consensus could not be achieved, no recommendation (0) was made. Consensus based on expert opinion was not used as a substitute for a lack of evidence. A consistent method for addressing potential conflict of interest was followed if task force members were coauthors of related research. The development of this guideline was independent of any industry funding. CONCLUSION These guidelines provide a roadmap for developing integrated, evidence-based, and patient-centered protocols for preventing and treating pain, agitation, and delirium in critically ill patients.
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Jung M, Metzger D. Purkinje-neuron-specific down-regulation of p38 protects motoric function from the repeated use of benzodiazepine. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/abb.2013.46a009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Roberts DJ, Haroon B, Hall RI. Sedation for critically ill or injured adults in the intensive care unit: a shifting paradigm. Drugs 2012; 72:1881-916. [PMID: 22950534 DOI: 10.2165/11636220-000000000-00000] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
As most critically ill or injured patients will require some degree of sedation, the goal of this paper was to comprehensively review the literature associated with use of sedative agents in the intensive care unit (ICU). The first and selected latter portions of this article present a narrative overview of the shifting paradigm in ICU sedation practices, indications for uninterrupted or prolonged ICU sedation, and the pharmacology of sedative agents. In the second portion, we conducted a structured, although not entirely systematic, review of the available evidence associated with use of alternative sedative agents in critically ill or injured adults. Data sources for this review were derived by searching OVID MEDLINE and PubMed from their first available date until May 2012 for relevant randomized controlled trials (RCTs), systematic reviews and/or meta-analyses and economic evaluations. Advances in the technology of mechanical ventilation have permitted clinicians to limit the use of sedation among the critically ill through daily sedative interruptions or other means. These practices have been reported to result in improved mortality, a decreased length of ICU and hospital stay and a lower risk of drug-associated delirium. However, in some cases, prolonged or uninterrupted sedation may still be indicated, such as when patients develop intracranial hypertension following traumatic brain injury. The pharmacokinetics of sedative agents have clinical importance and may be altered by critical illness or injury, co-morbid conditions and/or drug-drug interactions. Although use of validated sedation scales to monitor depth of sedation is likely to reduce adverse events, they have no utility for patients receiving neuromuscular receptor blocking agents. Depth of sedation monitoring devices such as the Bispectral Index (BIS©) also have limitations. Among existing RCTs, no sedative agent has been reported to improve the risk of mortality among the critically ill or injured. Moreover, although propofol may be associated with a shorter time to tracheal extubation and recovery from sedation than midazolam, the risk of hypertriglyceridaemia and hypotension is higher with propofol. Despite dexmedetomidine being linked with a lower risk of drug-associated delirium than alternative sedative agents, this drug increases risk of bradycardia and hypotension. Among adults with severe traumatic brain injury, there are insufficient data to suggest that any single sedative agent decreases the risk of subsequent poor neurological outcomes or mortality. The lack of examination of confounders, including the type of healthcare system in which the investigation was conducted, is a major limitation of existing pharmacoeconomic analyses, which likely limits generalizability of their results.
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Affiliation(s)
- Derek J Roberts
- Departments of Surgery, Community Health Sciences (Division of Epidemiology) and Critical Care Medicine, University of Calgary and the Foothills Medical Centre, Calgary, AB, Canada
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Abstract
Pharmacokinetics and pharmacodynamics can provide a useful modeling framework for predicting drug activity and can serve as a basis for dose optimization. Determining a suitable biomarker or surrogate measure of drug effect for pharmacodynamic models can be challenging. The electroencephalograph is a widely-available and non-invasive tool for recording brainwave activity simultaneously from multiple brain regions. Certain drug classes (such as drugs that act on the central nervous system) also generate a reproducible electroencephalogram (EEG) effect. Characterization of such a drug-induced EEG effect can produce pharmacokinetic/pharmacodynamic models useful for titrating drug levels and expediting development of chemically-similar drug analogs. This paper reviews the relevant concepts involved in pharmacokinetic/pharmacodynamic modeling using EEG-based pharmacodynamic measures. In addition, examples of such models for various drugs are organized by drug activity as well as chemical structure and presented.
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Morris C, Perris A, Klein J, Mahoney P. Anaesthesia in haemodynamically compromised emergency patients: does ketamine represent the best choice of induction agent? Anaesthesia 2009; 64:532-9. [PMID: 19413824 DOI: 10.1111/j.1365-2044.2008.05835.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In rapid sequence induction of anaesthesia in the emergency setting in shocked or hypotensive patients (e.g. ruptured abdominal aortic aneurysm, polytrauma or septic shock), prior resuscitation is often suboptimal and comorbidities (particularly cardiovascular) may be extensive. The induction agents with the most favourable pharmacological properties conferring haemodynamic stability appear to be ketamine and etomidate. However, etomidate has been withdrawn from use in some countries and impairs steroidogenesis. Ketamine has been traditionally contra-indicated in the presence of brain injury, but we argue in this review that any adverse effects of the drug on intracranial pressure or cerebral blood flow are in fact attenuated or reversed by controlled ventilation, subsequent anaesthesia and the greater general haemodynamic stability conferred by the drug. Ketamine represents a very rational choice for rapid sequence induction in haemodynamically compromised patients.
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Affiliation(s)
- C Morris
- Derby Hospitals Foundation Trust Derby, UK.
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Navarro V, Mazoit JX. [Drugs for status epilepticus treatment]. Rev Neurol (Paris) 2009; 165:355-65. [PMID: 19223054 DOI: 10.1016/j.neurol.2008.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 12/04/2008] [Indexed: 01/16/2023]
Abstract
The pharmacokinetics and pharmacodynamics of major antiepileptic agents are presented. The onset of action and the factors leading to extraction across the blood brain barrier are described as well as the mechanism and extent of metabolism, and the main interactions with other drugs. For each class, the dosing scheme and practical issues related to administration are described, based on evidence when available in the literature.
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Affiliation(s)
- V Navarro
- Unité d'épilepsie, département de neurophysiologie clinique, hôpital de la Pitié-Salpêtrière, AP-HP, Paris, France
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Continuous intravenous infusion of lorazepam as seizure prophylaxis in children treated with high-dose busulfan. Bone Marrow Transplant 2008; 42:135-6. [DOI: 10.1038/bmt.2008.91] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Masica AL, Girard TD, Wilkinson GR, Thomason JW, Truman Pun B, Nair UB, Light RW, Canonico AE, Dunn J, Pandharipande P, Shintani AK, Ely EW. Clinical sedation scores as indicators of sedative and analgesic drug exposure in intensive care unit patients. ACTA ACUST UNITED AC 2007; 5:218-31. [DOI: 10.1016/j.amjopharm.2007.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2007] [Indexed: 11/30/2022]
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Kimiskidis VK, Papagiannopoulos S, Kazis DA, Sotirakoglou K, Vasiliadis G, Zara F, Kazis A, Mills KR. Lorazepam-induced effects on silent period and corticomotor excitability. Exp Brain Res 2006; 173:603-11. [PMID: 16525803 DOI: 10.1007/s00221-006-0402-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Accepted: 02/04/2006] [Indexed: 10/24/2022]
Abstract
TMS studies on the CNS effects of benzodiazepines have provided contradictory results. The objective of this study is to describe the effects of lorazepam on silent period (SP) and corticomotor excitability. Twelve healthy male subjects (median age 35 years) were studied at baseline, following i.v. lorazepam administration and after reversal of the benzodiazepine effects with i.v. flumazenil. Lorazepam was given at a low-dose in one subject (0.0225 mg/kg bolus + 2 microg/kg/h infusion) and at a high-dose (0.045 mg/kg bolus + 2.6 microg/kg/h infusion) in the rest. Threshold (Thr) was measured at 1% steps. SPs were investigated with two complementary methods. First, SPs were elicited using a wide range of stimulus intensities (SIs) (from 5 to 100% maximum SI at 5% increments). At each SI, four SPs were obtained and the average value of SP duration was used to construct a stimulus/response (S/R) curve of SI versus SP .The resulting S/R curves were then fitted to a Boltzman function, the best-fit values of which were statistically compared for each experimental condition (i.e., baseline vs. lorazepam vs. flumazenil). Second, a large number of SPs (n=100) was elicited during each of the three experimental conditions using blocks of four stimuli with an intensity alternating between MT and 200% MT. This method was employed so as to reveal the dynamic, time-varying effects of lorazepam and flumazenil on SP duration at two stimulus intensity (SI) levels. MEP recruitment curves were constructed at rest and during activation and fitted to a Boltzman function the best-fit values of which were statistically compared for each experimental condition. Lorazepam at a low dose did not affect Thr, SP, or the active MEP recruitment curves. The high dose also had no effect on Thr and the active MEPs whereas the resting MEP recruitment curves were depressed post-lorazepam at the higher range of stimulus intensities. With regard to SP, the Max value of the S/R curve decreased from 251+/-4.6 ms at baseline to 215.2+/-3.1 ms post-lorazepam (P<0.01). V50 also decreased significantly (from 47.92+/-0.9% to 43.73+/-0.81%, P<0.01) whereas there was no significant change regarding slope and SP Thr. The statistical analysis of the SP S/R curves as well as the study of SPs at two SI levels revealed that lorazepam reduced SP duration when high intensity stimuli were used (>60%). In contrast, at low SIs a small increase in SP duration was noted post-drug. Enhancement of GABAergic inhibition by lorazepam results in a reduction of SP duration when high SIs is used. At the lower range of SIs, a small but statistically significant increase in SP duration is observed. The kinetic behavior of this phenomenon as well as the possible underlying mechanisms are discussed.
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Affiliation(s)
- V K Kimiskidis
- Department of Neurology III, G.Papanikolaou Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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Papini O, da Cunha SP, da Silva Mathes ADC, Bertucci C, Moisés ECD, de Barros Duarte L, de Carvalho Cavalli R, Lanchote VL. Kinetic disposition of lorazepam with focus on the glucuronidation capacity, transplacental transfer in parturients and racemization in biological samples. J Pharm Biomed Anal 2006; 40:397-403. [PMID: 16143486 DOI: 10.1016/j.jpba.2005.07.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Accepted: 07/20/2005] [Indexed: 11/22/2022]
Abstract
The present study investigates the kinetic disposition with focus on the racemization, glucuronidation capacity and the transplacental transfer of lorazepam in term parturients during labor. The study was conducted on 10 healthy parturients aged 18-37 years with a gestational age of 36-40.1 weeks, treated with a single oral dose of 2 mg racemic lorazepam 2-9 h before delivery. Maternal venous blood and urine samples were obtained over a 0-48 h interval and the umbilical cord sample was obtained immediately after clamping. Lorazepam enantiomers were determined in plasma and urine samples by LC-MS/MS using a Chiralcel OD-R column. In vitro racemization of lorazepam required the calculation of the pharmacokinetic parameters as isomeric mixtures. The data were fitted to two-compartment model and the pharmacokinetic parameters are reported as means (95% CI): t(1/2a) 3.2h (2.6-3.7 h), K(a) 0.23 h(-1) (0.19-0.28 h(-1)), t(1/2) 10.4h (9.4-11.3h), beta 0.068 h(-1) (0.061-0.075h(-1)), AUC(0-infinity) 175.3(ngh)/ml (145.7-204.8(ngh)/ml), Cl/F 2.6 ml/(minkg) (2.3-2.9 ml/(minkg)), Vd/F178.8l (146.5-211.1l), Fel 0.3% (0.1-0.5%), and Cl(R) 0.010 ml/(minkg) (0.005-0.015 ml/(minkg)). Placental transfer of lorazepam evaluated as the ratio of vein umbilical/maternal vein plasma concentrations, obtained as an isomeric mixture, was 0.73 (0.52-0.94). Pregnancy changes the pharmacokinetics of lorazepam, with an increase in the apparent distribution volume, an increase in apparent oral clearance, and a reduction of elimination half-life. The increase in oral clearance may indicate an increase in glucuronidation capacity, with a possible reduction in the plasma concentrations of drugs depending on glucuronidation capacity as the major metabolic pathway.
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Affiliation(s)
- Olga Papini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Avenida do Café s/n Campus da USP, 14040-903 Ribeirão Preto, SP, Brazil
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Papini O, Bertucci C, da Cunha SP, Dos Santos NAG, Lanchote VL. Quantitative assay of lorazepam and its metabolite glucuronide by reverse-phase liquid chromatography-tandem mass spectrometry in human plasma and urine samples. J Pharm Biomed Anal 2006; 40:389-96. [PMID: 16243469 DOI: 10.1016/j.jpba.2005.07.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Revised: 07/21/2005] [Accepted: 07/27/2005] [Indexed: 11/19/2022]
Abstract
A LC/MS/MS method for the quantitative determination of lorazepam in human plasma and urine samples was developed and validated. The enantioselective assay allowed to separate the enantiomers and to verify the stereochemical instability of lorazepam. The linearity assessed for lorazepam unchanged was 0.2-20 ng of each enantiomer/ml plasma and 0.2-15 ng of each enantiomer/ml urine. The linearity assessed for total lorazepam (after enzymatic hydrolysis) was 1-30 ng of each enantiomer/ml plasma and 10-150 ng of each enantiomer/ml urine. The coefficients of variation obtained for the intra- and interassay precision were less than 15%. The method was applied to the investigation of the kinetic disposition and metabolism of racemic lorazepam administered as a single oral dose of 2 mg to a parturient. The occurrence of racemization required the calculation of the pharmacokinetic parameters as enantiomeric mixtures of lorazepam (t(1/2a) 3.5h; K(a) 0.198 ngh(-1); t(1/2) 11.5h; beta 0.060 h(-1); AUC(0-infinity) 192.1ngh/ml; CLt/f 2.41ml/minkg; Vd/f 173.5l; Fel 0.41%, and Cl(R) 0.0099 ml/minkg) and its metabolite lorazepam-glucuronide (t(1/2f) 1.2h; K(f) 0.578 h(-1); t(1/2) 16.6h; beta 0.042 h(-1); AUC(0-infinity) 207.6 ngh/ml; Fel 51.80%, and Cl(R) 98.32 ml/minkg). However, the determined confidence limits make the method suitable for application to clinical pharmacokinetic studies, even if the quantification of both the enantiomers is required.
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Affiliation(s)
- Olga Papini
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Universidade de São Paulo, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Avenida do Café s/n, Campus da USP, 14040-903 Ribeirão Preto, Brazil
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Venkatakrishnan K, Culm KE, Ehrenberg BL, Harmatz JS, Corbett KE, Fleishaker JC, Greenblatt DJ. Kinetics and dynamics of intravenous adinazolam, N-desmethyl adinazolam, and alprazolam in healthy volunteers. J Clin Pharmacol 2005; 45:529-37. [PMID: 15831776 DOI: 10.1177/0091270004269105] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The pharmacokinetics and pharmacodynamics of adinazolam mesylate (10 mg), N-desmethyl adinazolam mesylate (NDMAD, 10 mg), and alprazolam (1 mg) were investigated in 9 healthy male subjects in a randomized, blinded, single-dose, 4-way crossover study. All drugs were intravenously infused over 30 minutes. Plasma adinazolam, NDMAD, and alprazolam concentrations, electroencephalographic (EEG) activity in the beta (12-30 Hz) range, performance on the Digit Symbol Substitution Test (DSST), and subjective measures of mood and sedation were monitored for 12 to 24 hours. Mean pharmacokinetic parameters for adinazolam, NDMAD, and alprazolam, respectively, were as follows: volume of distribution (L), 106, 100, and 77; elimination half-life (hours), 2.9, 2.8, and 14.6; and clearance (mL/min), 444, 321, and 84. More than 80% of the total infused adinazolam dose was converted to systemically appearing NDMAD. All 3 benzodiazepine agonists significantly increased beta EEG activity, with alprazolam showing the strongest agonist activity and adinazolam showing the weakest activity. Alprazolam and NDMAD significantly decreased DSST performance, whereas adinazolam had no effect relative to placebo. Adinazolam, NDMAD, and alprazolam all produced significant observer-rated sedation. Plots of EEG effect versus plasma alprazolam concentration demonstrated counterclockwise hysteresis, consistent with an effect site delay. This was incorporated into a kinetic-dynamic model in which hypothetical effect site concentration was related to pharmacodynamic EEG effect via the sigmoid E(max) model, yielding an effect site equilibration half-life of 4.8 minutes. The exponential effect model described NDMAD pharmacokinetics and EEG pharmacodynamics. The relation of both alprazolam and NDMAD plasma concentrations to DSST performance could be described by a modified exponential model. Pharmacokinetic-dynamic modeling was not possible for adinazolam, as the data did not conform to any known concentration-effect model. Collectively, these results indicate that the benzodiazepine-like effects occurring after adinazolam administration are mediated by mainly NDMAD.
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Affiliation(s)
- Karthik Venkatakrishnan
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
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Connemann BJ, Mann K, Lange-Asschenfeldt C, Ruchsow M, Schreckenberger M, Bartenstein P, Gründer G. Anterior limbic alpha-like activity: a low resolution electromagnetic tomography study with lorazepam challenge. Clin Neurophysiol 2005; 116:886-94. [PMID: 15792898 DOI: 10.1016/j.clinph.2004.11.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2004] [Revised: 10/23/2004] [Accepted: 11/15/2004] [Indexed: 11/21/2022]
Abstract
OBJECTIVE To verify findings of an independently regulated anterior limbic alpha band source. METHODS In a randomised cross-over study, the spontaneous EEG was recorded in nine healthy subjects after i.v. lorazepam or placebo. Intracerebral current densities within classical frequency bands were estimated with low resolution electromagnetic tomography [LORETA] and compared between groups with t-statistical parametric mapping [SPM[t]]. A region-of-interest [ROI] based method was used to compare frontal and occipital alpha band activity changes. RESULTS Irrespective of treatment group, local maxima of alpha band power were localised both in the occipital lobe, Brodman area [BA] 18, and in the anterior cingulate cortex [ACC], BA 32. Statistical parametric mapping showed reduced parieto-occipital, but unaltered frontal alpha band power after lorazepam. This result was confirmed by ROI-based comparison of BA 18 and BA 32. CONCLUSIONS There was an anterior limbic maximum of alpha band activity which, unlike occipital alpha, was not suppressed by lorazepam. SIGNIFICANCE The well-known anterior alpha band components may originate from a narrowly circumscribed source, located in the ACC. Frontal and occipital alpha band activities appear to be independently regulated.
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Affiliation(s)
- Bernhard J Connemann
- Department of Psychiatry III, University of Ulm, Leimgrubenweg 12, 89075 Ulm, Germany.
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Schreckenberger M, Lange-Asschenfeldt C, Lange-Asschenfeld C, Lochmann M, Mann K, Siessmeier T, Buchholz HG, Bartenstein P, Gründer G. The thalamus as the generator and modulator of EEG alpha rhythm: a combined PET/EEG study with lorazepam challenge in humans. Neuroimage 2004; 22:637-44. [PMID: 15193592 DOI: 10.1016/j.neuroimage.2004.01.047] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2003] [Revised: 01/27/2004] [Accepted: 01/28/2004] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Purpose of this study was to investigate the functional relationship between electroencephalographic (EEG) alpha power and cerebral glucose metabolism before and after pharmacological alpha suppression by lorazepam. METHODS Ten healthy male volunteers were examined undergoing two F18-fluorodeoxyglucose (18-FDG) positron emission tomography (PET) scans with simultaneous EEG recording: 1x placebo, 1x lorazepam. EEG power spectra were computed by means of Fourier analysis. The PET data were analyzed using SPM99, and the correlations between metabolism and alpha power were calculated for both conditions. RESULTS The comparison lorazepam versus placebo revealed reduced glucose metabolism of the bilateral thalamus and adjacent subthalamic areas, the occipital cortex and temporo-insular areas (P < 0.001). EEG alpha power was reduced in all derivations (P < 0.001). Under placebo, there was a positive correlation between alpha power and metabolism of the bilateral thalamus and the occipital and adjacent parietal cortex (P < 0.001). Under lorazepam, the thalamic and parietal correlations were maintained, whereas the occipital correlation was no longer detectable (P < 0.001). The correlation analysis of the difference lorazepam-placebo showed the alpha power exclusively correlated with the thalamic activity (P < 0.0001). CONCLUSIONS These results support the hypothesis of a close functional relationship between thalamic activity and alpha rhythm in humans mediated by corticothalamic loops which are independent of sensory afferences. The study paradigm could be a promising approach for the investigation of cortico-thalamo-cortical feedback loops in neuropsychiatric diseases.
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Greenblatt DJ, Ehrenberg BL, Culm KE, Scavone JM, Corbett KE, Friedman HL, Harmatz JS, Shader RI. Kinetics and EEG Effects of Midazolam during and after 1-Minute, 1-Hour, and 3-Hour Intravenous Infusions. J Clin Pharmacol 2004; 44:605-11. [PMID: 15145968 DOI: 10.1177/0091270004265368] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objective of this study was to evaluate the kinetics and dynamics of midazolam when administered by three different infusion schemes, using electroencephalography to measure pharmacodynamic effects. In a three-way crossover study, 8 volunteers received midazolam (0.1 mg/kg) by constant-rate intravenous infusion. The durations of midazolam infusions for the three trials were 1 minute, 1 hour, and 3 hours. Plasma midazolam concentrations and electroencephalographic (EEG) activity in the 13- to 30-Hz range were monitored for 24 hours. Based on separate analysis of each subject-trial, mean values for volume of distribution and distribution or elimination half-life did not significantly vary. Central compartment volume and clearance differed among the three midazolam infusion trials; however, the magnitude of change was small. EEG activity in the 13- to 30-Hz range significantly increased for all three midazolam infusion trials. Plots of midazolam plasma concentration versus pharmacodynamic EEG effect for the 1-hour and 3-hour infusion trials did not reveal evidence of either counterclockwise or clockwise hysteresis. Plots from the 1-minute infusion trial demonstrated counterclockwise hysteresis, consistent with an equilibration effect-site delay. This was incorporated into a kinetic-dynamic model in which hypothetical effect-site concentration was related to pharmacodynamic EEG effect via the sigmoid E(max) model. Analysis of all three infusion trials together yielded the following mean estimates: maximum EEG effect, 16.3% over baseline; 50% maximum effective concentration, 31 ng/mL; and an apparent rate constant for drug disappearance from the effect compartment which approached infinity. Despite the delay in effect onset during the 1-minute midazolam infusion, midazolam infusions in duration of up to 3 hours produce CNS sedation without evidence of tolerance.
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Affiliation(s)
- David J Greenblatt
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
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Abstract
Although the effective evaluation and management of agitated patients often receives less attention than other aspects of critical illness, it is among the most important and rewarding challenges that face critical care physicians. Key features of effective management include a thorough, organized search for potentially dangerous and correctable causes; a sound understanding of the pharmacology of analgesics and sedatives; and keeping a steady eye on appropriate management goals. In turn, the reward for excellent care will be shorter lengths of stay, more rapid liberation from mechanical ventilation, improved cognition, cost savings, and, perhaps, improved survival.
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Affiliation(s)
- Mark D Siegel
- Pulmonary and Critical Care Section, Yale University School of Medicine, Medical Intensive Care Unit, Yale-New Haven Hospital, New Haven, CT, USA.
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Kotegawa T, Laurijssens BE, Von Moltke LL, Cotreau MM, Perloff MD, Venkatakrishnan K, Warrington JS, Granda BW, Harmatz JS, Greenblatt DJ. In vitro, pharmacokinetic, and pharmacodynamic interactions of ketoconazole and midazolam in the rat. J Pharmacol Exp Ther 2002; 302:1228-37. [PMID: 12183684 DOI: 10.1124/jpet.102.035972] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Interactions of midazolam and ketoconazole were studied in vivo and in vitro in rats. Ketoconazole (total dose of 15 mg/kg intraperitoneally) reduced clearance of intravenous midazolam (5 mg/kg) from 79 to 55 ml/min/kg (p < 0.05) and clearance of intragastric midazolam (15 mg/kg) from 1051 to 237 ml/min/kg (p < 0.05), increasing absolute bioavailability from 0.11 to 0.36 (p < 0.05). Presystemic extraction occurred mainly across the liver as opposed to the gastrointestinal tract mucosa. Midazolam increased electroencephalographic (EEG) amplitude in the beta-frequency range. Ketoconazole shifted the concentration-EEG effect relationship rightward (increase in EC(50)), probably because ketoconazole is a neutral benzodiazepine receptor ligand. Ketoconazole competitively inhibited midazolam hydroxylation by rat liver and intestinal microsomes in vitro, with nanomolar K(i) values. At a total serum ketoconazole of 2 microg/ml (3.76 microM) in vivo, the predicted reduction in clearance of intragastric midazolam by ketoconazole (to 6% of control) was slightly greater than the observed reduction in vivo (to 15% of control). However, unbound serum ketoconazole greatly underpredicted the observed clearance reduction. Although the in vitro and in vivo characteristics of midazolam in rats incompletely parallel those in humans, the experimental model can be used to assess aspects of drug interactions having potential clinical importance.
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Affiliation(s)
- Tsutomu Kotegawa
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Tufts-New England Medical Center, 136 Harrison Avenue, Boston, MA 02111, USA
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Abstract
Several advances are likely to benefit the ICU patient requiring sedation, analgesia, and anxiolysis. The cooperative sedation induced by dexmedetomidine is a unique and valuable state that allows patients to be aroused easily and interferes little with ventilation. Remifentanil is the prototype of short-acting drugs, providing fast onset and offset; its relatively high cost may be balanced by limiting the risk for long-lasting respiratory depression. Lorazepam seems to be finding more proponents, especially in long-term ICU sedation where the costs of the newer agents may be prohibitive.
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Affiliation(s)
- M Maze
- Sir Ivan Magill Department of Anaesthetics and Intensive Care, Division of Surgery, Anaesthetics, and Intensive Care, Imperial College School of Medicine, Chelsea and Westminster Hospital, London, United Kingdom.
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