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Liu LQ, Hong PX, Song XH, Zhou CC, Ling R, Kang Y, Qi QR, Yang J. Design, Synthesis, and Activity Study of Water-Soluble, Rapid-Release Propofol Prodrugs. J Med Chem 2020; 63:7857-7866. [PMID: 32588620 DOI: 10.1021/acs.jmedchem.0c00698] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In this work, a series of water-soluble propofol prodrugs were synthesized, and their propofol release rate and pharmacodynamic characteristics were measured. We found that inserting glycolic acid as a linker between propofol and the cyclic amino acid accelerated the release of propofol from prodrugs into the plasma while preserving its safety. In animal experiments, prodrugs (3e, 3g, and 3j) were significantly better than fospropofol (the only water-soluble propofol prodrug that has been used clinically) in terms of safety, onset, and duration time of anesthesia. Their molar dose, onset time, and anesthesia duration time were comparable to those of propofol, helping to maintain the clinical benefits of propofol. The experimental results showed the potential of such compounds as water-soluble prodrugs of propofol.
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Affiliation(s)
- Liang-Quan Liu
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China.,Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Industrial Technology, Sichuan Research Center of Precision Engineering Technology for Small Molecule Drugs, West China School of Pharmacy Sichuan University, Chengdu 610041, China
| | - Pei-Xi Hong
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xing-Hai Song
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chang-Cui Zhou
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China
| | - Rui Ling
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yi Kang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qing-Rong Qi
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Industrial Technology, Sichuan Research Center of Precision Engineering Technology for Small Molecule Drugs, West China School of Pharmacy Sichuan University, Chengdu 610041, China
| | - Jun Yang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, Department of Anesthesiology, Sichuan University West China Hospital, Sichuan University, Chengdu 610041, China
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Zhang W, Yang J, Fan J, Wang B, Kang Y, Liu J, Zhang W, Zhu T. An improved water-soluble prodrug of propofol with high molecular utilization and rapid onset of action. Eur J Pharm Sci 2018; 127:9-13. [PMID: 30290219 DOI: 10.1016/j.ejps.2018.09.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/25/2018] [Accepted: 09/29/2018] [Indexed: 02/05/2023]
Abstract
Water-soluble prodrugs of propofol often carry an excess of propofol at the effective dose and have a slower onset of action. Sustained release of the original drug can result in propofol accumulation in the body after administration, causing delays in wakefulness. This situation causes the prodrug to lose the benefits of rapid onset and recovery from the effects of propofol. In the present study, HX0921 (sodium 2-(2-(2,6-diisopropylphenoxy)-2-oxoethoxy)acetate), an improved prodrug of propofol with high utilization of propofol and fast onset of action, was studied. The rate of propofol release from HX0921 was much faster than that from fospropofol (a marketed propofol prodrug) in rat plasma. The 50% effective dose (ED50) of propofol, HX0921 and fospropofol to induce anesthesia in rats was 5.78, 22.19 and 42.44 mg/kg, respectively. After administration at 2 × ED50, the onset time of anesthesia in the HX0921 group was significantly shorter than that in the fospropofol group (0.26 ± 0.15 min vs. 2.24 ± 0.35 min, P < 0.01) and the duration of anesthesia in the HX0921 group was also significantly shorter than that in the fospropofol group (22.35 ± 4.05 min vs. 29.15 ± 5.25 min, P < 0.01). These results suggest that the rapid onset and short action time of HX0921 was due to the rapid release and high molecular utilization of propofol carried by HX0921.
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Affiliation(s)
- Weiyi Zhang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Jun Yang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Jing Fan
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Bin Wang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Yi Kang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Wensheng Zhang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
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Bartkowska-Śniatkowska A, Bienert A, Wiczling P, Rosada-Kurasińska J, Zielińska M, Warzybok J, Borsuk A, Tibboel D, Kaliszan R, Grześkowiak E. Pharmacokinetics of sufentanil during long-term infusion in critically ill pediatric patients. J Clin Pharmacol 2015; 56:109-15. [PMID: 26105145 DOI: 10.1002/jcph.577] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/17/2015] [Indexed: 11/07/2022]
Abstract
The aim of this study was to develop a population pharmacokinetic model of sufentanil and to assess the influence of covariates in critically ill children admitted to a pediatric intensive care unit. After institutional approval, 41 children were enrolled in the study. Blood samples for pharmacokinetic (PK) assessment were collected from routinely placed arterial catheters during and after discontinuation of infusion. Population nonlinear mixed-effects modeling was performed using NONMEM. A 2-compartment model described sufentanil PK sufficiently. Typical values of the central and peripheral volume of distribution and the metabolic and intercompartmental clearance for a theoretical patient weighing 70 kg were VC = 7.90 l, VT = 481 L, Cl = 5.3 L/h, and Q = 38.3 L/h, respectively. High interindividual variability of all PK parameters was noted. Allometric/isometric principles to scale sufentanil PK revealed that to achieve the same steady-state sufentanil concentrations in plasma for pediatric patients of different body weights, the infusion rate should follow the formula (infusion rate for a 70-kg adult patient, μg/h) × (body weight/70 kg)(0.75). Severity of illness described by PRISM score, the monitored physiological and laboratory parameters, and coadministered drugs such as vasopressors were not found to be significant covariates.
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Affiliation(s)
| | - Agnieszka Bienert
- Department of Clinical Pharmacy and Biopharmacy, Poznan University of Medical Sciences, Poznan, Poland
| | - Paweł Wiczling
- Department of Biopharmaceutics and Pharmacodynamics, Medical University of Gdansk, Gdansk, Poland
| | - Jowita Rosada-Kurasińska
- Department of Pediatric Anesthesiology and Intensive Therapy, Poznan University of Medical Sciences, Poznan, Poland
| | - Marzena Zielińska
- Department of Anesthesiology and Intensive Care, Pediatric Intensive Care Unit, Wroclaw Medical University, Wroclaw, Poland
| | - Justyna Warzybok
- Department of Clinical Pharmacy and Biopharmacy, Poznan University of Medical Sciences, Poznan, Poland
| | - Agnieszka Borsuk
- Department of Biopharmaceutics and Pharmacodynamics, Medical University of Gdansk, Gdansk, Poland
| | - Dick Tibboel
- Intensive Care and Department of Pediatric Surgery, Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Roman Kaliszan
- Department of Biopharmaceutics and Pharmacodynamics, Medical University of Gdansk, Gdansk, Poland
| | - Edmund Grześkowiak
- Department of Clinical Pharmacy and Biopharmacy, Poznan University of Medical Sciences, Poznan, Poland
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Wang C, Allegaert K, Peeters MYM, Tibboel D, Danhof M, Knibbe CAJ. The allometric exponent for scaling clearance varies with age: a study on seven propofol datasets ranging from preterm neonates to adults. Br J Clin Pharmacol 2014; 77:149-59. [PMID: 23772816 PMCID: PMC3895356 DOI: 10.1111/bcp.12180] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Accepted: 06/02/2013] [Indexed: 11/29/2022] Open
Abstract
AIM For scaling clearance between adults and children, allometric scaling with a fixed exponent of 0.75 is often applied. In this analysis, we performed a systematic study on the allometric exponent for scaling propofol clearance between two subpopulations selected from neonates, infants, toddlers, children, adolescents and adults. METHODS Seven propofol studies were included in the analysis (neonates, infants, toddlers, children, adolescents, adults1 and adults2). In a systematic manner, two out of the six study populations were selected resulting in 15 combined datasets. In addition, the data of the seven studies were regrouped into five age groups (FDA Guidance 1998), from which four combined datasets were prepared consisting of one paediatric age group and the adult group. In each of these 19 combined datasets, the allometric scaling exponent for clearance was estimated using population pharmacokinetic modelling (nonmem 7.2). RESULTS The allometric exponent for propofol clearance varied between 1.11 and 2.01 in cases where the neonate dataset was included. When two paediatric datasets were analyzed, the exponent varied between 0.2 and 2.01, while it varied between 0.56 and 0.81 when the adult population and a paediatric dataset except for neonates were selected. Scaling from adults to adolescents, children, infants and neonates resulted in exponents of 0.74, 0.70, 0.60 and 1.11 respectively. CONCLUSIONS For scaling clearance, ¾ allometric scaling may be of value for scaling between adults and adolescents or children, while it can neither be used for neonates nor for two paediatric populations. For scaling to neonates an exponent between 1 and 2 was identified.
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Affiliation(s)
- Chenguang Wang
- Division of Pharmacology, LACDR, Leiden University, Leiden, the Netherlands; Intensive Care and Department of Paediatric Intensive Care, Erasmus MC Sophia Children's Hospital, Rotterdam, the Netherlands
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Diepstraten J, Chidambaran V, Sadhasivam S, Blussé van Oud-Alblas HJ, Inge T, van Ramshorst B, van Dongen EPA, Vinks AA, Knibbe CAJ. An integrated population pharmacokinetic meta-analysis of propofol in morbidly obese and nonobese adults, adolescents, and children. CPT Pharmacometrics Syst Pharmacol 2013; 2:e73. [PMID: 24026252 PMCID: PMC4026632 DOI: 10.1038/psp.2013.47] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/09/2013] [Indexed: 01/22/2023] Open
Abstract
This study describes a population pharmacokinetic meta-analysis of propofol to characterize the influence of body size measures and age in morbidly obese and nonobese adults, adolescents, and children. Sixty morbidly obese and nonobese adult patients (55-167 kg; 21-79 years) and 34 morbidly obese and nonobese adolescents and children (37-184 kg; 9-20 years) were included. The results show that clearance increased with total body weight in an allometric function while age was found to influence clearance in a bilinear fashion with two distinct slopes, reflecting an initial increase and subsequent decrease as a result of aging. Using these two functions, the influence of both (over)weight and age on propofol clearance was well characterized, which may provide a basis for dosing across this diverse group of patients.CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e73; doi:10.1038/psp.2013.47; advance online publication 11 September 2013.
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Affiliation(s)
- J Diepstraten
- Department of Clinical Pharmacy, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - V Chidambaran
- Department of Anesthesiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - S Sadhasivam
- Department of Anesthesiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - T Inge
- Department of Surgery, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - B van Ramshorst
- Department of Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - E P A van Dongen
- Department of Anesthesiology and Intensive Care, St. Antonius Hospital, Nieuwegein, The Netherlands
| | - A A Vinks
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - C A J Knibbe
- Department of Clinical Pharmacy, St. Antonius Hospital, Nieuwegein, The Netherlands
- Division of Pharmacology, Leiden/Amsterdam Center for Drug Research, Leiden, The Netherlands
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Wang C, Peeters MYM, Allegaert K, Blussé van Oud-Alblas HJ, Krekels EHJ, Tibboel D, Danhof M, Knibbe CAJ. A bodyweight-dependent allometric exponent for scaling clearance across the human life-span. Pharm Res 2012; 29:1570-81. [PMID: 22287046 PMCID: PMC3349030 DOI: 10.1007/s11095-012-0668-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 01/03/2012] [Indexed: 11/25/2022]
Abstract
Purpose To explore different allometric equations for scaling clearance across the human life-span using propofol as a model drug. Methods Data from seven previously published propofol studies ((pre)term neonates, infants, toddlers, children, adolescents and adults) were analysed using NONMEM VI. To scale clearance, a bodyweight-based exponential equation with four different structures for the exponent was used: (I) 3/4 allometric scaling model; (II) mixture model; (III) bodyweight-cut-point separated model; (IV) bodyweight-dependent exponent model. Results Model I adequately described clearance in adults and older children, but overestimated clearance of neonates and underestimated clearance of infants. Use of two different exponents in Model II and Model III showed significantly improved performance, but yielded ambiguities on the boundaries of the two subpopulations. This discontinuity was overcome in Model IV, in which the exponent changed sigmoidally from 1.35 at a hypothetical bodyweight of 0 kg to a value of 0.56 from 10 kg onwards, thereby describing clearance of all individuals best. Conclusions A model was developed for scaling clearance over the entire human life-span with a single continuous equation, in which the exponent of the bodyweight-based exponential equation varied with bodyweight.
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Affiliation(s)
- Chenguang Wang
- Division of Pharmacology, LACDR, Leiden University, Leiden, the Netherlands
- Intensive Care and Department of Paediatric Surgery, Erasmus MC Sophia Children’s Hospital, Rotterdam, the Netherlands
| | - Mariska Y. M. Peeters
- Department of Clinical Pharmacy, St. Antonius Hospital, P.O. Box 2500, 3430 EM Nieuwegein, the Netherlands
| | - Karel Allegaert
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | | | - Elke H. J. Krekels
- Division of Pharmacology, LACDR, Leiden University, Leiden, the Netherlands
- Intensive Care and Department of Paediatric Surgery, Erasmus MC Sophia Children’s Hospital, Rotterdam, the Netherlands
| | - Dick Tibboel
- Intensive Care and Department of Paediatric Surgery, Erasmus MC Sophia Children’s Hospital, Rotterdam, the Netherlands
| | - Meindert Danhof
- Division of Pharmacology, LACDR, Leiden University, Leiden, the Netherlands
| | - Catherijne A. J. Knibbe
- Division of Pharmacology, LACDR, Leiden University, Leiden, the Netherlands
- Intensive Care and Department of Paediatric Surgery, Erasmus MC Sophia Children’s Hospital, Rotterdam, the Netherlands
- Department of Clinical Pharmacy, St. Antonius Hospital, P.O. Box 2500, 3430 EM Nieuwegein, the Netherlands
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7
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van Kralingen S, Diepstraten J, Peeters MYM, Deneer VHM, van Ramshorst B, Wiezer RJ, van Dongen EPA, Danhof M, Knibbe CAJ. Population pharmacokinetics and pharmacodynamics of propofol in morbidly obese patients. Clin Pharmacokinet 2012; 50:739-50. [PMID: 21973271 DOI: 10.2165/11592890-000000000-00000] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND OBJECTIVES In view of the increasing prevalence of morbidly obese patients, the influence of excessive total bodyweight (TBW) on the pharmacokinetics and pharmacodynamics of propofol was characterized in this study using bispectral index (BIS) values as a pharmacodynamic endpoint. METHODS A population pharmacokinetic and pharmacodynamic model was developed with the nonlinear mixed-effects modelling software NONMEM VI, on the basis of 491 blood samples from 20 morbidly obese patients (TBW range 98-167 kg) and 725 blood samples from 44 lean patients (TBW range 55-98 kg) from previously published studies. In addition, 2246 BIS values from the 20 morbidly obese patients were available for pharmacodynamic analysis. RESULTS In a three-compartment pharmacokinetic model, TBW proved to be the most predictive covariate for clearance from the central compartment (CL) in the 20 morbidly obese patients (CL 2.33 L/min × [TBW/70]^[0.72]). Similar results were obtained when the morbidly obese patients and the 44 lean patients were analysed together (CL 2.22 L/min × [TBW/70]^[0.67]). No covariates were identified for other pharmacokinetic parameters. The depth of anaesthesia in the morbidly obese patients was adequately described by a two-compartment biophase-distribution model with a sigmoid maximum possible effect (E(max)) pharmacodynamic model (concentration at half-maximum effect [EC(50)] 2.12 mg/L) without covariates. CONCLUSION We developed a pharmacokinetic and pharmacodynamic model of propofol in morbidly obese patients, in which TBW proved to be the major determinant of clearance, using an allometric function with an exponent of 0.72. For the other pharmacokinetic and pharmacodynamic parameters, no covariates could be identified. Trial registration number (clinicaltrials.gov): NCT00395681.
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Affiliation(s)
- Simone van Kralingen
- Department of Anesthesiology and Intensive Care, St Antonius Hospital, Nieuwegein, the Netherlands
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Sim JY, Lee SH, Park DY, Jung JA, Ki KH, Lee DH, Noh GJ. Pain on injection with microemulsion propofol. Br J Clin Pharmacol 2008; 67:316-25. [PMID: 19220277 DOI: 10.1111/j.1365-2125.2008.03358.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS To evaluate the incidence and severity of injection pain caused by microemulsion propofol and lipid emulsion propofol in relation to plasma bradykinin generation and aqueous free propofol concentrations. METHODS Injection pain was evaluated in 147 patients. Aqueous free propofol concentrations in each formulation, and in formulation mixtures containing agents that reduce propofol-induced pain, were measured by high-performance liquid chromatography. Plasma bradykinin concentrations in both formulations and in their components mixed with blood sampled from six volunteers were measured by radioimmunoassays. Injection pain caused by 8% polyethylene glycol 660 hydroxystearate (PEG660 HS) was evaluated in another 10 volunteers. RESULTS The incidence of injection pain [visual analogue scale (VAS) >30 mm] caused by microemulsion and lipid emulsion propofol was 69.7 and 42.3% (P < 0.001), respectively. The median VAS scores for microemulsion and lipid emulsion propofol were 59 and 24 mm, respectively (95% confidence interval for the difference 12.5, 40.0). The aqueous free propofol concentration of microemulsion propofol was seven times higher than that of lipid emulsion propofol. Agents that reduce injection pain did not affect aqueous free propofol concentrations. Microemulsion propofol and 8% PEG660 HS enhanced plasma bradykinin generation, whereas lipid emulsion propofol and lipid solvent did not. PEG660 HS did not cause injection pain. CONCLUSIONS Higher aqueous free propofol concentrations of microemulsion propofol produce more frequent and severe pain. The plasma kallikrein-kinin system may not be involved, and the agents that reduce injection pain may not act by decreasing aqueous free propofol concentrations.
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Affiliation(s)
- Ji-Yeon Sim
- Department of Anesthesiology and Pain Medicine, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea
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McLean S, Boyle RR, Brandon S, Davies NW, Sorensen JS. Pharmacokinetics of 1,8-cineole, a dietary toxin, in the brushtail possum (Trichosurus vulpecula): Significance for feeding. Xenobiotica 2008; 37:903-22. [PMID: 17896321 DOI: 10.1080/00498250701570277] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
1,8-Cineole (cineole) is a Eucalyptus leaf toxin that defends against predation by herbivores such as the brushtail possum (Trichosurus vulpecula). The aim of the current study was to characterize the pharmacokinetics of cineole in the possum to improve understanding about how possums can avoid cineole toxicity when eating a Eucalyptus diet. Nine male possums were trapped in the wild and acclimated to captivity; a subcutaneous port was then implanted for venous blood sampling. Cineole was administered intravenously (10 and 15 mg kg(-1)) via a lateral tail vein and orally (30, 100 and 300 mg kg(-1)) by gavage, and blood concentrations of cineole and its metabolites were determined by gas chromatography. Cineole had a large terminal volume of distribution (V(z) = 27 l kg(-1)) and a high clearance (43 ml min(-1) kg(-1)), equal to hepatic blood flow. The terminal half-life was approximately 7 h. Oral bioavailability was low (F = 0.05) after low doses, but increased tenfold with dose, probably due to saturable first-pass metabolism. These findings indicate that when possums feed on a cineole diet, they eat until the cineole consumed is sufficient to saturate pre-systemic metabolism, leading to a rapid rise in bioavailability and cineole blood levels, and a cessation of the feeding bout. This is the first report on the pharmacokinetics of a dietary toxin in a wild herbivore, and provides insights into the interactions between the blood concentration of a plant secondary metabolite and the browsing behaviour of a herbivore.
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Affiliation(s)
- S McLean
- School of Pharmacy, University of Tasmania, Hobart, Tasmania, Australia.
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Schicher M, Polsinger M, Hermetter A, Prassl R, Zimmer A. In vitro release of propofol and binding capacity with regard to plasma constituents. Eur J Pharm Biopharm 2008; 70:882-8. [PMID: 18640268 DOI: 10.1016/j.ejpb.2008.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 06/18/2008] [Accepted: 06/23/2008] [Indexed: 11/28/2022]
Abstract
PURPOSE New evidence suggests that the anesthetic effect of parenteral propofol emulsions varies between commercial preparations. We examined and compared different propofol preparations to determine propofol release and binding capacity with regard to plasma lipoproteins and albumin. METHODS We created a novel assay consisting of microtiter plates coated with either low-density lipoprotein (LDL) or albumin to analyze propofol binding kinetics. Using high performance liquid chromatography (HPLC), we measured propofol release from the oily phase and the corresponding amount of propofol bound to the plates in a time-dependent manner and at equilibrium conditions attained after 30 min of incubation at 37 degrees C. The concentrations of free propofol in the aqueous phase of different propofol preparations - Diprivan, and the generic formulations Propofol "Fresenius" (1% and 2% propofol) and Propofol-Lipuro - were analyzed using ultracentrifugation or dialysis for phase separation. Finally, we investigated the effect of isolated lipoprotein fractions on propofol release. RESULTS Propofol bound to LDL-coated plates with approximately twofold higher affinity than to albumin-coated plates. No significant differences in total propofol release were observed between preparations. Moreover, similar amounts of free propofol were observed in the aqueous phase of all products tested (1% propofol preparations: 18 microg/ml; 2% propofol preparations: 35 microg/ml), except for the medium-chain and long-chain triglyceride (MCT/LCT) preparation studied, in which the concentration of free propofol was lower. Lipoproteins had no effect on propofol release, except for high-density lipoprotein (HDL), which triggered almost 100% release from the oily phase at HDL concentrations above 1000 microg/ml. CONCLUSIONS No differences were observed between the binding/release capacity and lipoprotein interactions of any of the propofol preparations tested. We propose that clinical observations of inconsistent propofol activity are related to variations in the lipoprotein profile, enzyme activity or genetic disorders of individual patients, rather than to the propofol preparation itself.
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Mizuno J, Akune T, Tsuda T, Fukui Y, Otsuji M, Kin N, Saito Y, Orii R, Hayashida M, Arita H, Hanaoka K. Time course of systolic and diastolic blood pressure decreases during the preintubation period of anesthesia induction: modeling with a logistic function. J Clin Anesth 2007; 19:497-505. [PMID: 18063203 DOI: 10.1016/j.jclinane.2007.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 04/06/2007] [Accepted: 04/10/2007] [Indexed: 11/18/2022]
Abstract
STUDY OBJECTIVE To investigate whether systolic (SBP) and diastolic blood pressure (DBP) decreases during the preintubation period could be expressed as 4-parameter logistic and cubic functions giving S-shaped curves. DESIGN Prospective, clinical study. SETTING Operating room of a metropolitan general hospital. PATIENTS Seven ASA physical status I and II patients scheduled for elective spinal surgery during general anesthesia. INTERVENTIONS Anesthesia was induced with fentanyl, propofol, and vecuronium injection followed by inhalation of sevoflurane. MEASUREMENTS The SBP and DBP data were recorded at all beats from fentanyl injection to direct laryngoscopy. The respective changes were analyzed using a logistic function: P(t) = p(L) + (q(L) - p(L))/(1 + exp{[4 m(L)/(q(L) - p(L))][k(L) - t]}) and a cubic function: P(t) = at(3) + bt(2) + ct + d, where parameter p(L) is the upper asymptote, q(L) is the lower asymptote, m(L) is the slope at the inflection point, and k(L) is the time to the inflection point and where a, b, and c are coefficients, and d are constants. Goodness of fit of the two functions was compared using a correlation coefficient and residual mean squares. Each parameter was compared with the corresponding observed data. MAIN RESULTS Logistic correlation coefficient values for SBP and DBP decreases were larger than the cubic correlation coefficient values (0.990 [Z transformation: 2.64 +/- 0.32] vs 0.981 [Z: 2.32 +/- 0.37] and 0.977 [Z: 2.22 +/- 0.33] vs 0.967 [Z: 2.05 +/- 0.34], respectively; P < 0.05). Logistic residual mean squares values for SBP and DBP decreases were smaller than cubic residual mean squares values (20.6 vs 41.0 and 9.2 vs 13.7 mmHg(2), respectively; P < 0.05). There were significant correlations between p(L) and SBP or DBP after anesthesia induction, between q(L) and SBP or DBP before endotracheal intubation, and between k(L) and time to maximal rate of the SBP or DBP decrease (dP/dt(min)), but no significant correlation between m(L) and dP/dt(min) for SBP or DBP. CONCLUSIONS Time courses of SBP and DBP decreases during the preintubation period of anesthesia induction are modeled effectively by a logistic function.
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Affiliation(s)
- Ju Mizuno
- Department of Anesthesiology, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
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Knibbe CAJ, Naber H, Aarts LPHJ, Kuks PFM, Danhof M. Long-term sedation with propofol 60 mg ml(-1) vs. propofol 10 mg(-1) ml in critically ill, mechanically ventilated patients. Acta Anaesthesiol Scand 2004; 48:302-7. [PMID: 14982562 DOI: 10.1111/j.1399-6576.2004.0339.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Hypertriglyceridaemia is the main cause of therapeutic failure during propofol use in long-term sedated mechanically ventilated patients. Propofol 60 mg ml(-1) has been developed to reduce fat and volume load for the critically ill patient. The purpose of the study was to compare the effectiveness of sedation, achievability of effective concentrations and the effects on serum lipid concentrations of propofol 60 mg ml(-1) vs. propofol 10 mg ml(-1) for long-term sedation in critically ill patients. METHODS In this randomized, open, prospective study, 20 critically ill, mechanically ventilated patients who required sedation for a minimum of 48 h received propofol 60 mg ml(-1) or propofol 10 mg ml(-1) in doses as required during 2-5 days. RESULTS No differences between propofol 60 mg ml(-1) and propofol 10 mg ml(-1) were observed in the effectiveness of sedation using the Ramsay Sedation score and the Subjective Sedation score, nor in relation to the propofol concentrations. Between the two groups, there were no significant differences in the daily propofol dose, number of daily infusion rate adjustments or need for additional sedatives. Mean serum triglyceride concentrations were higher in the propofol 10 mg ml(-1) group compared with the propofol 60 mg ml(-1) group [5.26 (3.19) vs. 3.22 (2.05) mmol l(-1), P > 0.05][mean (SD)]. Patients in the propofol 10 mg ml(-1) group received more fat from the propofol infusion than from the propofol 60 mg ml(-1) group [53.2 (29.6) vs. 10.0 (4.7) % compared with fat from nutrition, respectively]. A significant relationship was observed between the daily total fat dose and the serum triglyceride concentration (r2 = 0.32, P < 0.001), whereas there was no significant correlation between the daily propofol dose and the serum triglyceride concentration. CONCLUSION Propofol 60 mg ml(-1) is a useful alternative to propofol 10 mg ml(-1) for the long-term sedation of critically ill patients. Sedation with propofol 60 mg ml(-1) reduces fat and volume load by 83%, which reduces the risk of hypertriglyceridaemia.
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Affiliation(s)
- C A J Knibbe
- Department of Clinical Pharmacy, St Antonius Hospital, Nieuwegein, the Netherlands.
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Abad-Santos F, Gálvez-Múgica MA, Santos MA, Novalbos J, Gallego-Sandín S, Méndez P, Casimiro C, Gilsanz F. Pharmacokinetics and pharmacodynamics of a single bolus of propofol 2% in healthy volunteers. J Clin Pharmacol 2003; 43:397-405. [PMID: 12723460 DOI: 10.1177/0091270003251391] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study was undertaken to assess the bioequivalence between a new formulation of propofol 2% and the commercially available product Diprivan. Secondary objectives were to compare the times to onset of and emergence from hypnosis, the hemodynamic effects, and the safety profiles. Twelve healthy male volunteers were included in a randomized crossover study. Subjects were administered a 2-mg/kg single bolus injection of each formulation separated by a 7- to 10-day washout period. Plasma propofol was determined by reversed-phase liquid chromatography with fluorescence detection. Eleven subjects completed the study, and both formulations were considered bioequivalent. There were no serious or severe adverse events. The concentration-time profiles of all the subjects could adequately be described using a three-compartment model. The mean times to cessation of counting out loud (17 vs. 18 s) and to eye opening (245 vs. 244 s) were not statistically different between treatment groups. Moreover, they seem to show some degree of pharmacodynamic bioequivalence, although a higher number of subjects are necessary to unequivocally demonstrate it.
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Affiliation(s)
- Francisco Abad-Santos
- Service of Clinical Pharmacology, Hospital Universitario de la Princesa, Instituto Teófilo Hernando, Universidad Autónoma de Madrid, Madrid, Spain
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Abstract
Intravenous anaesthetic agents are generally remarkably safe. However, it is clear that propofol infusion syndrome is a real, albeit rare, entity. This often lethal syndrome of metabolic acidosis, acute cardiomyopathy and skeletal myopathy is strongly associated with infusions of propofol at rates of 5 mg/kg/hour and greater for more than 48 hours. There is evidence to support the hypothesis that the syndrome is caused by the failure of free fatty acid metabolism due to inhibition of free fatty acid entry into the mitochondria and also specific sites in the mitochondrial respiratory chain. The syndrome therefore mimics the mitochondrial myopathies. Midazolam causes seizure-like activity in very-low-birthweight premature infants requiring the drug prior to tracheal intubation or during prolonged positive pressure ventilation. This can be successfully reversed with the specific benzodiazepine antagonist flumazenil. Midazolam can also cause paradoxical reactions, including increased agitation, poor co-operation and aggressive or violent behaviour, which has been successfully managed with flumazenil.
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Affiliation(s)
- Timothy G Short
- Department of Anaesthesia, Auckland Hospital, Park Road, Grafton, Auckland I, New Zealand
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Knibbe CAJ, Melenhorst-de Jong G, Mestrom M, Rademaker CMA, Reijnvaan AFA, Zuideveld KP, Kuks PFM, van Vught H, Danhof M. Pharmacokinetics and effects of propofol 6% for short-term sedation in paediatric patients following cardiac surgery. Br J Clin Pharmacol 2002; 54:415-22. [PMID: 12392590 PMCID: PMC1874439 DOI: 10.1046/j.1365-2125.2002.01652.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2001] [Accepted: 05/10/2002] [Indexed: 11/20/2022] Open
Abstract
AIMS This paper describes the pharmacokinetics and effects of propofol in short-term sedated paediatric patients. METHODS Six mechanically ventilated children aged 1-5 years received a 6 h continuous infusion of propofol 6% at the rate of 2 or 3 mg kg-1 h-1 for sedation following cardiac surgery. A total of seven arterial blood samples was collected at various time points during and after the infusion in each patient. Pharmacokinetic modelling was performed using NONMEM. Effects were assessed on the basis of the Ramsay sedation score as well as a subjective sedation scale. RESULTS The data were best described by a two-compartment pharmacokinetic model. In the model, body weight was a significant covariate for clearance. Pharmacokinetic parameters in the weight-proportional model were clearance (CL) = 35 ml kg-1 min-1, volume of central compartment (V1) = 12 l, intercompartmental clearance (Q) = 0.35 l min-1 and volume of peripheral compartment (V2) = 24 l. The interindividual variabilities for these parameters were 8%, < 1%, 11% and 35%, respectively. Compared with the population pharmacokinetics in adults following cardiac surgery and when normalized for body weight, statistically significant differences were observed the parameters CL and V1 (35 vs 29 ml kg-1 min-1 and 0.78 vs 0.26 l kg-1P < 0.05), whereas the values for Q and V2 were similar (23 vs 18 ml kg-1 min-1 and 1.6 vs 1.8 l kg-1, P > 0.05). In children, the percentage of adequately sedated patients was similar compared with adults (50% vs 67%) despite considerably higher propofol concentrations (1.3 +/- 0.10 vs 0.51 +/- 0.035 mg l-1, mean +/- s.e. mean), suggesting a lower pharmacodynamic sensitivity to propofol in children. CONCLUSIONS In children aged 1-5 years, a pharmacokinetic model for propofol was described using sparse data. In contrast to adults, body weight was a significant covariate for clearance in children. The model may serve as a useful basis to study the role of covariates in the pharmacokinetics and pharmacodynamics of propofol in paediatric patients of different ages.
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Affiliation(s)
- Catherijne A J Knibbe
- Department of Clinical Pharmacy, St Antonius Hospital, PO Box 2500, 3430 EM Nieuwegein, The Netherlands.
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Weigt HU, Georgieff M, Beyer C, Föhr KJ. Activation of Neuronal N-Methyl-d-Aspartate Receptor Channels by Lipid Emulsions. Anesth Analg 2002. [DOI: 10.1213/00000539-200202000-00018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Weigt HU, Georgieff M, Beyer C, Föhr KJ. Activation of neuronal N-methyl-D-aspartate receptor channels by lipid emulsions. Anesth Analg 2002; 94:331-7, table of contents. [PMID: 11812693 DOI: 10.1097/00000539-200202000-00018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
UNLABELLED Lipid emulsions are widely used as carriers for hypnotics such as propofol, etomidate, and diazepam. It is assumed that the emulsions alone exert no effect on cellular functions nor influence the pharmacokinetics, pharmacodynamics, or anesthetic and analgetic potency of the hypnotics they carry. To elucidate possible interactions between lipid emulsions and cell membranes, in particular membrane-bound proteins, we investigated the effects of commercially available lipid emulsions on the cell membranes of cultured cortical neurons from the mouse by using the whole-cell configuration of the patch-clamp technique. Of nine lipid emulsions tested, three, i.e., Intralipid, Structolipid, and, to a much lesser extent, Abbolipid, activated membrane currents in the neuronal cells in a dilution-dependent manner. The emulsion-induced currents were not affected by picrotoxin or bicuculline but were inhibited by DL-AP5 and ketamine. The voltage dependence of the currents was influenced by the presence of Mg(2+) in a way that is typical for currents conducted by N-methyl-D-aspartate receptor channels. We conclude that Intralipid, Structolipid, and Abbolipid activate N-methyl-D-aspartate receptor channels in cortical neurons. IMPLICATIONS Lipid emulsions are widely used as carriers for hypnotics such as propofol, etomidate, or diazepam. We tested nine commercially available lipid emulsions and demonstrate that three of them--Intralipid, Structolipid, and Abbolipid--activate NMDA receptor channels in the membranes of cortical neuronal cells.
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