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van Groen BD, Krekels EHJ, Mooij MG, van Duijn E, Vaes WHJ, Windhorst AD, van Rosmalen J, Hartman SJF, Hendrikse NH, Koch BCP, Allegaert K, Tibboel D, Knibbe CAJ, de Wildt SN. The Oral Bioavailability and Metabolism of Midazolam in Stable Critically Ill Children: A Pharmacokinetic Microtracing Study. Clin Pharmacol Ther 2021; 109:140-149. [PMID: 32403162 PMCID: PMC7818442 DOI: 10.1002/cpt.1890] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 04/15/2020] [Indexed: 12/21/2022]
Abstract
Midazolam is metabolized by the developmentally regulated intestinal and hepatic drug-metabolizing enzyme cytochrome P450 (CYP) 3A4/5. It is frequently administered orally to children, yet knowledge is lacking on the oral bioavailability in term neonates up until 1 year of age. Furthermore, the dispositions of the major metabolites 1-OH-midazolam (OHM) and 1-OH-midazolam-glucuronide (OHMG) after oral administration are largely unknown for the entire pediatric age span. We aimed to fill these knowledge gaps with a pediatric [14 C]midazolam microtracer population pharmacokinetic study. Forty-six stable, critically ill children (median age 9.8 (range 0.3-276.4) weeks) received a single oral [14 C]midazolam microtracer (58 (40-67) Bq/kg) when they received a therapeutic continuous intravenous midazolam infusion and had an arterial line in place enabling blood sampling. For midazolam, in a one-compartment model, bodyweight was a significant predictor for clearance (0.98 L/hour) and volume of distribution (8.7 L) (values for a typical individual of 5 kg). The typical oral bioavailability in the population was 66% (range 25-85%). The exposures of OHM and OHMG were highest for the youngest age groups and significantly decreased with postnatal age. The oral bioavailability of midazolam, largely reflective of intestinal and hepatic CYP3A activity, was on average lower than the reported 49-92% for preterm neonates, and higher than the reported 21% for children> 1 year of age and 30% for adults. As midazolam oral bioavailability varied widely, systemic exposure of other CYP3A-substrate drugs after oral dosing in this population may also be unpredictable, with risk of therapy failure or toxicity.
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Affiliation(s)
- Bianca D. van Groen
- Intensive Care and Pediatric SurgeryErasmus Medical Center – Sophia Children’s HospitalRotterdamThe Netherlands
| | - Elke H. J. Krekels
- Leiden Academic Center for Drug ResearchLeiden UniversityLeidenThe Netherlands
| | - Miriam G. Mooij
- Department of PediatricsLeiden University Medical CentreLeidenThe Netherlands
| | | | | | - Albert D. Windhorst
- Amsterdam University Medical Centers – Location VU Medical CenterAmsterdamThe Netherlands
| | - Joost van Rosmalen
- Department of BiostatisticsErasmus Medical CenterRotterdamthe Netherlands
| | - Stan J. F. Hartman
- Department of Pharmacology and ToxicologyRadboud University Medical CenterRadboud Institute for Health SciencesNijmegenThe Netherlands
| | - N. Harry Hendrikse
- Amsterdam University Medical Centers – Location VU Medical CenterAmsterdamThe Netherlands
| | - Birgit C. P. Koch
- Department of Hospital PharmacyErasmus Medical CenterRotterdamThe Netherlands
| | - Karel Allegaert
- Department of Hospital PharmacyErasmus Medical CenterRotterdamThe Netherlands
- Katholieke Universiteit LeuvenLeuvenBelgium
| | - Dick Tibboel
- Intensive Care and Pediatric SurgeryErasmus Medical Center – Sophia Children’s HospitalRotterdamThe Netherlands
| | - Catherijne A. J. Knibbe
- Leiden Academic Center for Drug ResearchLeiden UniversityLeidenThe Netherlands
- St Antonius HospitalNieuwegeinThe Netherlands
| | - Saskia N. de Wildt
- Intensive Care and Pediatric SurgeryErasmus Medical Center – Sophia Children’s HospitalRotterdamThe Netherlands
- Department of Pharmacology and ToxicologyRadboud University Medical CenterRadboud Institute for Health SciencesNijmegenThe Netherlands
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Evaluation of IV to Enteral Benzodiazepine Conversion Calculations in a Pediatric Intensive Care Setting. Pediatr Crit Care Med 2018; 19:e569-e575. [PMID: 30080777 DOI: 10.1097/pcc.0000000000001687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To evaluate if institutionally established calculations for transitioning continuous IV midazolam to enteral benzodiazepines maintain Withdrawal Assessment Tool-Version 1 scores equal to or less than preconversion values. DESIGN Retrospective cohort study evaluating the effectiveness and safety of benzodiazepine conversion calculations embedded within an institution-specific clinical pathway for sedation and weaning of mechanically ventilated pediatric patients. SETTING A 55-bed, mixed-medical, noncardiac surgical PICU in a tertiary care children's hospital. PATIENTS All patients age 6 months to 18 years who received continuous midazolam for 5 days or longer while mechanically ventilated for 5-21 days and were then converted to either enteral diazepam or lorazepam following extubation (or return to baseline ventilator settings in tracheostomy-dependent patients) between January 1, 2015, and June 30, 2016. INTERVENTIONS Benzodiazepine conversion calculations were applied according to institutional clinical pathway guidance. MEASUREMENTS AND MAIN RESULTS Withdrawal Assessment Tool-Version 1 scores were compared pre and post benzodiazepine conversion. Patient demographics, benzodiazepine dose escalations, as needed benzodiazepine requirements, and severe adverse events within 48 hours of conversion were assessed. Seventy-one patient encounters were analyzed (median age, 2.5 yr; interquartile range, 1.2-5.3). The median Withdrawal Assessment Tool-Version 1 scores pre conversion and post conversion were not significantly different (1 [interquartile range, 0.75-2] and 1 [interquartile range, 0.25-2], respectively, p = 0.1). As needed benzodiazepine doses were administered in 38% of encounters post conversion, but escalation of a scheduled enteral benzodiazepine regimen was only required in 2.8% of encounters. Post conversion, one patient (1.4%) had increased seizure activity, and four patients (5.6%) required fluid boluses secondary to tachycardia or dehydration, but not hypotension. CONCLUSIONS These findings suggest that standardized benzodiazepine conversions successfully achieved consistent Withdrawal Assessment Tool-Version 1 scores compared with preconversion values. Severe adverse events associated with oversedation and/or withdrawal were minimal and confounded by underlying disease states.
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Brussee JM, Vet NJ, Krekels EHJ, Valkenburg AJ, Jacqz-Aigrain E, van Gerven JMA, Swart EL, van den Anker JN, Tibboel D, de Hoog M, de Wildt SN, Knibbe CAJ. Predicting CYP3A-mediated midazolam metabolism in critically ill neonates, infants, children and adults with inflammation and organ failure. Br J Clin Pharmacol 2017; 84:358-368. [PMID: 29072785 PMCID: PMC5777436 DOI: 10.1111/bcp.13459] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/04/2017] [Accepted: 10/19/2017] [Indexed: 12/14/2022] Open
Abstract
AIMS Inflammation and organ failure have been reported to have an impact on cytochrome P450 (CYP) 3A-mediated clearance of midazolam in critically ill children. Our aim was to evaluate a previously developed population pharmacokinetic model both in critically ill children and other populations, in order to allow the model to be used to guide dosing in clinical practice. METHODS The model was evaluated externally in 136 individuals, including (pre)term neonates, infants, children and adults (body weight 0.77-90 kg, C-reactive protein level 0.1-341 mg l-1 and 0-4 failing organs) using graphical and numerical diagnostics. RESULTS The pharmacokinetic model predicted midazolam clearance and plasma concentrations without bias in postoperative or critically ill paediatric patients and term neonates [median prediction error (MPE) <30%]. Using the model for extrapolation resulted in well-predicted clearance values in critically ill and healthy adults (MPE <30%), while clearance in preterm neonates was over predicted (MPE >180%). CONCLUSION The recently published pharmacokinetic model for midazolam, quantifying the influence of maturation, inflammation and organ failure in children, yields unbiased clearance predictions and can therefore be used for dosing instructions in term neonates, children and adults with varying levels of critical illness, including healthy adults, but not for extrapolation to preterm neonates.
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Affiliation(s)
- Janneke M Brussee
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands
| | - Nienke J Vet
- Department of Pediatrics, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Elke H J Krekels
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands
| | - Abraham J Valkenburg
- Intensive Care and Department of Pediatric Surgery, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Evelyne Jacqz-Aigrain
- Department of Pediatric Pharmacology and Pharmacogenetics, Hôpital Robert Debré, Paris, France
| | | | - Eleonora L Swart
- Department of Clinical Pharmacology and Pharmacy, VU University Medical Centre, Amsterdam, The Netherlands
| | - Johannes N van den Anker
- Intensive Care and Department of Pediatric Surgery, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands.,Division of Paediatric Pharmacology and Pharmacometrics, University of Basel Children's Hospital, Basel, Switzerland.,Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA
| | - Dick Tibboel
- Department of Pediatrics, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Matthijs de Hoog
- Department of Pediatrics, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Saskia N de Wildt
- Intensive Care and Department of Pediatric Surgery, Erasmus MC - Sophia Children's Hospital, Rotterdam, The Netherlands.,Department of Pharmacology and Toxicology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Catherijne A J Knibbe
- Division of Systems Biomedicine and Pharmacology, Leiden Academic Centre for Drug Research (LACDR), Leiden University, Leiden, The Netherlands.,Department of Clinical Pharmacy, St Antonius Hospital, Nieuwegein, The Netherlands
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Germovsek E, Barker CIS, Sharland M, Standing JF. Scaling clearance in paediatric pharmacokinetics: All models are wrong, which are useful? Br J Clin Pharmacol 2016; 83:777-790. [PMID: 27767204 PMCID: PMC5346879 DOI: 10.1111/bcp.13160] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 10/06/2016] [Accepted: 10/15/2016] [Indexed: 12/11/2022] Open
Abstract
Linked Articles This article is commented on in the editorial by Holford NHG and Anderson BJ. Why standards are useful for predicting doses. Br J Clin Pharmacol 2017; 83: 685–7. doi: 10.1111/bcp.13230 Aim When different models for weight and age are used in paediatric pharmacokinetic studies it is difficult to compare parameters between studies or perform model‐based meta‐analyses. This study aimed to compare published models with the proposed standard model (allometric weight0.75 and sigmoidal maturation function). Methods A systematic literature search was undertaken to identify published clearance (CL) reports for gentamicin and midazolam and all published models for scaling clearance in children. Each model was fitted to the CL values for gentamicin and midazolam, and the results compared with the standard model (allometric weight exponent of 0.75, along with a sigmoidal maturation function estimating the time in weeks of postmenstrual age to reach half the mature value and a shape parameter). For comparison, we also looked at allometric size models with no age effect, the influence of estimating the allometric exponent in the standard model and, for gentamicin, using a fixed allometric exponent of 0.632 as per a study on glomerular filtration rate maturation. Akaike information criteria (AIC) and visual predictive checks were used for evaluation. Results No model gave an improved AIC in all age groups, but one model for gentamicin and three models for midazolam gave slightly improved global AIC fits albeit using more parameters: AIC drop (number of parameters), –4.1 (5), –9.2 (4), –10.8 (5) and –10.1 (5), respectively. The 95% confidence interval of estimated CL for all top performing models overlapped. Conclusion No evidence to reject the standard model was found; given the benefits of standardised parameterisation, its use should therefore be recommended.
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Affiliation(s)
- Eva Germovsek
- Inflammation, Infection and Rheumatology Section, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
| | - Charlotte I S Barker
- Inflammation, Infection and Rheumatology Section, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.,St George's University Hospitals NHS Foundation Trust, Blackshaw Road, London, UK
| | - Mike Sharland
- Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.,St George's University Hospitals NHS Foundation Trust, Blackshaw Road, London, UK
| | - Joseph F Standing
- Inflammation, Infection and Rheumatology Section, Great Ormond Street Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK.,Paediatric Infectious Diseases Research Group, Institute for Infection and Immunity, St George's, University of London, Cranmer Terrace, London, SW17 0RE, UK
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Abstract
OBJECTIVES To determine the extent of inter-individual variation in clearance of midazolam in children and establish which factors are responsible for this variation. METHODS A systematic literature review was performed to identify papers describing the clearance of midazolam in children. The following databases were searched: Medline, Embase, International Pharmaceutical Abstracts, CINAHL and Cochrane Library. From the papers, the range in plasma clearance and the coefficient of variation (CV) in plasma clearance were determined. RESULTS 25 articles were identified. Only 13 studies gave the full range of clearance values for individual patients. The CV was greater in critically ill patients (18%-170%) than non-critically ill patients (13%-54%). Inter-individual variation was a major problem in all age groups of critically ill patients. The CV was 72%-106% in preterm neonates, 18%-73% in term neonates, 31%-130% in infants, 21%-170% in children and 47%-150% in adolescents. The mean clearance was higher in children (1.1-16.7 mL/min/kg) than in neonates (0.78-2.5 mL/min/kg). CONCLUSIONS Large inter-individual variation was seen in midazolam clearance values in critically ill neonates, infants, children and adolescents.
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Affiliation(s)
- Mohammed I Altamimi
- Academic Division of Child Health, University of Nottingham, Derbyshire Children's Hospital, Derby, UK
| | - Helen Sammons
- Academic Division of Child Health, University of Nottingham, Derbyshire Children's Hospital, Derby, UK
| | - Imti Choonara
- Academic Division of Child Health, University of Nottingham, Derbyshire Children's Hospital, Derby, UK
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Korzeniewska-Eksterowicz A, Przysło Ł, Fendler W, Stolarska M, Młynarski W. Palliative sedation at home for terminally ill children with cancer. J Pain Symptom Manage 2014; 48:968-74. [PMID: 24751437 DOI: 10.1016/j.jpainsymman.2014.01.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 01/07/2014] [Accepted: 01/08/2014] [Indexed: 11/20/2022]
Abstract
CONTEXT The presence of symptoms that are difficult to control always requires adjustment of treatment, and palliative sedation (PS) should be considered. OBJECTIVES We analyzed our experience in conducting PS at home for terminally ill children with cancer during a seven-year period. METHODS We performed a retrospective analysis of medical records of children with cancer treated at home between the years 2005 and 2011. RESULTS We analyzed the data of 42 cancer patients (18% of all patients); in 21 cases, PS was initiated (solid tumors n = 11, brain tumors [5], bone tumors [4], leukemia [1]). Sedation was introduced because of pain (n = 13), dyspnea (9), anxiety (5), or two of those symptoms (6). The main drug used for sedation was midazolam; all patients received morphine. There were no significant differences in the dose of morphine or midazolam depending on the patient's sex; age was correlated with an increase of midazolam dose (R = 0.68; P = 0.005). Duration of sedation (R = 0.61; P = 0.003) and its later initiation (R = 0.43; P = 0.05) were correlated with an increase of the morphine dose. All patients received adjuvant treatment; in patients who required a morphine dose increase, metoclopramide was used more often (P = 0.0002). Patients did not experience any adverse reactions. Later introduction of sedation was associated with a marginally higher number of intervention visits and a significantly higher number of planned visits (R = 0.53; P = 0.013). CONCLUSION Sedation may be safely used at home. It requires close monitoring and full cooperation between the family and hospice team. Because of the limited data on home PS in pediatric populations, further studies are needed.
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Affiliation(s)
- Aleksandra Korzeniewska-Eksterowicz
- Pediatric Palliative Care Unit, Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland; Gajusz Foundation, Pediatric Palliative Care Center - Home Hospice for Children of Lodz Region, Lodz, Poland.
| | - Łukasz Przysło
- Pediatric Palliative Care Unit, Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland; Gajusz Foundation, Pediatric Palliative Care Center - Home Hospice for Children of Lodz Region, Lodz, Poland
| | - Wojciech Fendler
- Pediatric Palliative Care Unit, Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland; Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland
| | - Małgorzata Stolarska
- Pediatric Palliative Care Unit, Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland; Gajusz Foundation, Pediatric Palliative Care Center - Home Hospice for Children of Lodz Region, Lodz, Poland; Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland
| | - Wojciech Młynarski
- Pediatric Palliative Care Unit, Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland; Department of Pediatrics, Oncology, Hematology and Diabetology, Medical University of Lodz, Lodz, Poland
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Postovsky S, Moaed B, Krivoy E, Ofir R, Ben Arush MW. Practice of palliative sedation in children with brain tumors and sarcomas at the end of life. Pediatr Hematol Oncol 2007; 24:409-15. [PMID: 17710658 DOI: 10.1080/08880010701451079] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Despite progress in the treatment of pediatric cancer, approximately 25% of these children will die of the disease. The last period of life is characterized by profound physical and psychological suffering, both of the children and their loved ones. Adequate alleviation of this suffering becomes the priority in the management of these patients. The authors retrospectively evaluated the indications, incidence, and characteristics of palliative sedation (PS) in 19 children with brain tumors (BT) and 18 with sarcomas (S) at the end of life. Twelve of the 18 S patients received PS, as did 13 of the 19 BT patients. Indications for initiation of PS for those with BT were seizures and/or pain, for those with S were pain and/or respiratory insufficiency. It was concluded that PS may be the only efficacious and safe treatment for the alleviation of suffering in these children at the end of life, despite differing indications.
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Affiliation(s)
- Sergey Postovsky
- Department of Pediatric Hematology-Oncology, Meyer Children's Hospital, Rambam Health Care Campus, Haifa, Israel. s
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Treluyer JM, Zohar S, Rey E, Hubert P, Iserin F, Jugie M, Lenclen R, Chevret S, Pons G. Minimum effective dose of midazolam for sedation of mechanically ventilated neonates. J Clin Pharm Ther 2005; 30:479-85. [PMID: 16164495 DOI: 10.1111/j.1365-2710.2005.00678.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine the minimal effective dose (MED) of intravenous midazolam, required for appropriate sedation in 95% of patients, 1 h after drug administration. METHODS A double-blind dose-finding study using the continual reassessment method, a Bayesian sequential design. Twenty-three newborn infants hospitalized in intensive care unit participated. Inclusion criteria were: (i) post-natal age <28 days, (ii) gestational age >33 weeks, (iii) intubation and ventilatory support required for respiratory distress syndrome, (iv) need for sedation (i.e. one of the six following criteria: agitation or grimacing or crying facial expression before tracheal suctioning, agitation or grimacing or crying facial expression during tracheal suctioning). Each neonate was allocated to a loading dose, ranging from 75 to 200 microg/kg, and a maintenance dose ranging from 37.5 to 100 microg/kg/h. RESULTS The primary endpoint was the level of sedation 1 h after the onset of infusion. The sedation procedure was classified as a success if all the following clinical criteria were met: no agitation, no grimacing and no crying facial expression before as well as during tracheal suctioning. Based on the 23 patients, the final estimated probability of success was 76.9% (95% credibility interval: 56.6-91.4%) for the 200 microg/kg loading dose. no significant adverse effect was observed. CONCLUSIONS Continual reassessment is a new approach, suitable for dose-finding study in neonates. this method overcomes some of the ethical, statistical and practical problems associated with this population. Using this method, the MED was estimated to be the 200 mug/kg loading dose of midazolam.
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Affiliation(s)
- J-M Treluyer
- Pharmacologie, Hôpital Cochin-Saint-Vincent de Paul, AP-HP, Université Paris V, Paris, France.
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Bolon M, Boulieu R, Flamens C, Paulus S, Bastien O. [Sedation induced by midazolam in intensive care: pharmacologic and pharmacokinetic aspects]. ANNALES FRANCAISES D'ANESTHESIE ET DE REANIMATION 2002; 21:478-92. [PMID: 12134593 DOI: 10.1016/s0750-7658(02)00662-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Review on midazolam in order to optimize drug utilisation and therapeutic monitoring. DATA SOURCES Research of English or French articles published until August 2001, using Medline database. The key words were: midazolam, pharmacokinetics, pharmacodynamic, sedation, drug interaction. STUDY SELECTION Original articles, clinical cases and letters to the Editor were selected. Animal studies were excluded. DATA EXTRACTION The articles were analysed according to their interest in midazolam clinical practice. DATA SYNTHESIS Midazolam is a benzodiazepine widely used in intensive care unit, as a sedative, anxiety-relieving, and amnesic drug. Midazolam could be used in patients with cardiac, or respiratory failure, and in neurosurgery. A great interindividual variability on pharmacokinetic and pharmacodynamic response was observed. In intensive care patients, elimination half-life is known to be widely increased. Midazolam is metabolised by hepatic microsomes. The major metabolite is the 1-hydroxymidazolam, which is pharmacologically active. A prolonged sedation due to an accumulation of conjugated metabolite was observed in renal failure patients. Enzymatic inductors or inhibitors could influence pharmacokinetics and pharmacodynamic effects of midazolam. CONCLUSION According to midazolam pharmacokinetic and pharmacodynamic variability, an individual dosage adjustment is essential for long-term sedation. Target controlled sedation could be a mean to limit the variability and to reach quickly the pharmacodynamic effect.
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Affiliation(s)
- M Bolon
- Université Claude Bernard Lyon 1, institut des sciences pharmaceutiques et biologiques, département de pharmacie clinique, de pharmacocinétique et d'évaluation du médicament, 8, avenue Rockefeller, 69373 Lyon, France
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