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Pan X, Giustarini D, Lang F, Rossi R, Wieder T, Köberle M, Ghashghaeinia M. Desipramine induces eryptosis in human erythrocytes, an effect blunted by nitric oxide donor sodium nitroprusside and N-acetyl-L-cysteine but enhanced by Calcium depletion. Cell Cycle 2023; 22:1827-1853. [PMID: 37522842 PMCID: PMC10599211 DOI: 10.1080/15384101.2023.2234177] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 06/29/2023] [Accepted: 06/30/2023] [Indexed: 08/01/2023] Open
Abstract
Background: Desipramine a representative of tricyclic antidepressants (TCAs) promotes recovery of depressed patients by inhibition of reuptake of neurotransmitters serotonin (SER) and norepinephrine (NE) in the presynaptic membrane by directly blocking their respective transporters SERT and NET.Aims: To study the effect of desipramine on programmed erythrocyte death (eryptosis) and explore the underlying mechanisms.Methods: Phosphatidylserine (PS) exposure on the cell surface as marker of cell death was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry. Hemolysis was determined photometrically, and intracellular glutathione [GSH]i from high performance liquid chromatography.Results: Desipramine dose-dependently significantly enhanced the percentage of annexin-V-binding cells and didn´t impact glutathione (GSH) synthesis. Desipramine-induced eryptosis was significantly reversed by pre-treatment of erythrocytes with either nitric oxide (NO) donor sodium nitroprusside (SNP) or N-acetyl-L-cysteine (NAC). The highest inhibitory effect was obtained by using both inhibitors together. Calcium (Ca2+) depletion aggravated desipramine-induced eryptosis. Changing the order of treatment, i.e. desipramine first followed by inhibitors, could not influence the inhibitory effect of SNP or NAC.Conclusion: Antidepressants-caused intoxication can be treated by SNP and NAC, respectively. B) Patients with chronic hypocalcemia should not be treated with tricyclic anti-depressants or their dose should be noticeably reduced.
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Affiliation(s)
- Xia Pan
- Physiological Institute, Department of Vegetative and Clinical Physiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Daniela Giustarini
- Department of Biotechnology Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Florian Lang
- Physiological Institute, Department of Vegetative and Clinical Physiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Ranieri Rossi
- Department of Biotechnology Chemistry and Pharmacy, University of Siena, Siena, Italy
| | - Thomas Wieder
- Physiological Institute, Department of Vegetative and Clinical Physiology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Martin Köberle
- Department of Dermatology and Allergology, School of Medicine, Technical University of Munich, München, Germany
| | - Mehrdad Ghashghaeinia
- Physiological Institute, Department of Vegetative and Clinical Physiology, Eberhard Karls University of Tübingen, Tübingen, Germany
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Karna SR, Chambers P, Singh P, Lopez-Villalobos N, Kongara K. Evaluation of analgesic interaction between morphine, maropitant and dexmedetomidine in dogs undergoing ovariohysterectomy. N Z Vet J 2021; 70:10-21. [PMID: 33950785 DOI: 10.1080/00480169.2021.1927231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
ABSTRACTAims: To compare the analgesic effect of morphine combined with maropitant and/or dexmedetomidine to morphine alone but at a higher dose, and to evaluate the pharmacokinetics of the drug combinations, in dogs undergoing ovariohysterectomy (OHE).Methods: Forty client-owned dogs were randomised into four treatment groups (n = 10 per group) each to receive a different analgesic protocol. After premedication with I/M acepromazine, anaesthesia was induced with propofol to effect and maintained with isoflurane in 100% oxygen delivered via a circle system. The heart rate, respiratory rate, blood pressure, haemoglobin oxygen saturation, end-tidal partial pressure of carbon dioxide, electrocardiogram and rectal temperature were monitored during anaesthesia. The test drugs (Mor: 0.6 mg/kg morphine; Maro + Mor: 0.3 mg/kg morphine and 1 mg/kg maropitant; Dex + Mor: 0.3 mg/kg morphine and 10 μg/kg dexmedetomidine; Dex + Maro + Mor: 0.2 mg/kg morphine, 7 μg/kg dexmedetomidine and 0.7 mg/kg maropitant) were administered I/M after induction of anaesthesia and 30 minutes before the expected start time of ovariohysterectomy, which was carried out by veterinary students under veterinary supervision. The short form of the Glasgow composite measure pain scale (CMPS-SF) and visual analogue scale (VAS) were used for pain assessment at 15 and 30 minutes and 1, 2, 3, 6, 9 and 24 hours after extubation. Dogs with CMPS-SF pain score ≥ 6 received rescue analgesia with S/C buprenorphine (0.02 mg/kg). Blood samples were collected before, 15, 30, 60 and 120 minutes after injection of the test drugs and concentration of the test drugs in plasma was determined by liquid chromatography-mass spectrometry.Results: Dogs that received Dex + Mor had significantly lower CMPS-SF (estimate of difference = -1.53 (SE 0.58); p = 0.010) and VAS (estimate of difference = -0.67 (SE 0.25); p = 0.007) scores compared to the dogs that received morphine alone. There was no evidence of a difference in the number of dogs requiring rescue between groups. All dogs that received dexmedetomidine showed cardiac arrhythmia and second-degree heart block. Mean (SD) maximum concentrations (Cmax,) of morphine in plasma were 6.8 (4.56), 9.56 (8.29), 9.30 (3.35) and 18.99 (9.41) ng/mL for the groups Dex + Mor, Dex + Maro + Mor, Maro + Mor and Mor respectively. The Cmax of morphine was significantly lower in the Dex + Mor (p = 0.004), Dex + Maro + Mor (p = 0.034) and Maro + Mor (p = 0.018) groups compared to the Mor group.Conclusions For dogs undergoing ovariohysterectomy, lower doses of morphine (0.2 and 0.3 mg/kg) combined with dexmedetomidine or maropitant may provide analgesia equivalent to or better than morphine when given alone at a higher dose (0.6 mg/kg).Abbreviations: AUC: Area under curve; Cmax: Maximum concentration in plasma; CMPS-SF: Glasgow composite measure pain scale - short form; NK1: Neurokinin-1; OHE: Ovariohysterectomy; Tmax: Time to Cmax; T1/2: Half-life of terminal elimination phase; VAS: Visual analogue scale.
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Affiliation(s)
- S R Karna
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P Chambers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - P Singh
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - N Lopez-Villalobos
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - K Kongara
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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Karna SR, Singh P, Chambers P, Kongara K. Pharmacokinetics of morphine in combination with dexmedetomidine and maropitant following intramuscular injection in dogs anaesthetized with halothane. J Vet Pharmacol Ther 2019; 43:153-161. [PMID: 31856324 DOI: 10.1111/jvp.12831] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/18/2019] [Accepted: 11/27/2019] [Indexed: 11/27/2022]
Abstract
The purpose of this study was to evaluate the pharmacokinetics of morphine in combination with dexmedetomidine and maropitant injected intramuscularly in dogs under general anaesthesia. Eight healthy dogs weighing 25.76 ± 3.16 kg and 3.87 ± 1.64 years of age were used in a crossover study. Dogs were randomly allocated to four groups: (1) morphine 0.6 mg/kg; (2) morphine 0.3 mg/kg + dexmedetomidine 5 μg/kg; (3) morphine 0.3 mg/kg + maropitant 1 mg/kg; (4) morphine 0.2 mg/kg + dexmedetomidine 3 μg/kg + maropitant 0.7 mg/kg. Blood samples were collected before, 15 and 30 min, and 1, 2, 3 4, 6 and 8 hr after injection of the test drugs. Plasma concentration of the drugs was determined by liquid chromatography-mass spectrometry. The elimination half-life (T1/2 ) of morphine was higher and the clearance rate (CL) was lower when combined with dexmedetomidine (T1/2 = 77.72 ± 20.27 min, CL = 119.41 ± 23.34 ml kg-1 min-1 ) compared to maropitant (T1/2 = 52.73 min ± 13.823 ml kg-1 min-1 , CL = 178.57 ± 70.55) or morphine alone at higher doses (T1/2 = 50.53 ± 12.55 min, CL = 187.24 ± 34.45 ml kg-1 min-1 ). Combining morphine with dexmedetomidine may increase the dosing interval of morphine and may have a clinical advantage.
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Affiliation(s)
- Sandeep Raj Karna
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Preet Singh
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Paul Chambers
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
| | - Kavitha Kongara
- School of Veterinary Science, Massey University, Palmerston North, New Zealand
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Poulin P. Drug Distribution to Human Tissues: Prediction and Examination of the Basic Assumption in In Vivo Pharmacokinetics-Pharmacodynamics (PK/PD) Research. J Pharm Sci 2015; 104:2110-2118. [PMID: 25808270 DOI: 10.1002/jps.24427] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 12/25/2022]
Abstract
The tissue:plasma partition coefficients (Kp ) are good indicators of the extent of tissue distribution. Therefore, advanced tissue composition-based models were used to predict the Kp values of drugs under in vivo conditions on the basis of in vitro and physiological input data. These models, however, focus on animal tissues and do not challenge the predictions with human tissues for drugs. The first objective of this study was to predict the experimentally determined Kp values of seven human tissues for 26 drugs. In all, 95% of the predicted Kp values are within 2.5-fold error of the observed values in humans. Accordingly, these results suggest that the tissue composition-based model used in this study is able to provide accurate estimates of drug partitioning in the studied human tissues. Furthermore, as the Kp equals to the ratio of total concentration between tissue and plasma, or the ratio of unbound fraction between plasma (fup ) and tissue (fut ), this parameter Kp would deviate from the unity. Therefore, the second objective was to examine the corresponding relationships between fup and fut values experimentally determined in humans for several drugs. The results also indicate that fup may significantly deviate to fut ; the discrepancies are governed by the dissimilarities in the binding and ionization on both sides of the membrane, which were captured by the tissue composition-based model. Hence, this violated the basic assumption in in vivo pharmacokinetics-pharmacodynamics (PK/PD) research, since the free drug concentration in tissue and plasma was not equal particularly for the ionizable drugs due to the pH gradient effect on the fraction of unionized drug in plasma (fuip ) and tissue (fuit ) (i.e., fup × fuip × total plasma concentration = fut × fuit × total tissue concentration, and, hence, the free drug concentration in plasma and tissue differed by fuip/fuit). Therefore, this assumption should be adjusted for the ionized drugs, and, hence, a mathematical correction to the basic assumption of similar free drug concentration in plasma and tissues can be derived from the tissue composition-based model. Note that this assumption will be further challenged in a dynamic in vivo system in a companion manuscript. Overall, this study was a first attempt to predict the in vivo Kp values for specific human tissues by considering separately the effect of fup and fut , with the aim of facilitating the use of physiologically-based PK (PBPK) model in PK/PD studies.
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The role of the protein-binding on the mode of drug action as well the interactions with other drugs. Eur J Drug Metab Pharmacokinet 2008; 33:225-30. [DOI: 10.1007/bf03190876] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sakamoto K, Mikami H, Kimura J. Involvement of organic anion transporting polypeptides in the toxicity of hydrophilic pravastatin and lipophilic fluvastatin in rat skeletal myofibres. Br J Pharmacol 2008; 154:1482-90. [PMID: 18500364 PMCID: PMC2492093 DOI: 10.1038/bjp.2008.192] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Accepted: 04/14/2008] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND AND PURPOSE There is a discrepancy in the adverse effect of 3-hydroxy-3-methylglutaryl-CoA reductase inhibitors, statins between the clinical reports and the studies using skeletal muscle cell models. In the clinical reports, both hydrophilic and lipophilic statins induce myotoxicity, whereas in in vitro experiments using cell lines of myoblasts, lipophilic, but not hydrophilic, statins exert myotoxicity. We investigated the cause of this discrepancy. EXPERIMENTAL APPROACH Skeletal myofibres, fibroblasts and satellite cells were isolated from rat flexor digitorum brevis (FDB) muscles. Using these primary cultured cells as well as the L6 myoblast cell line, we compared the toxicity of hydrophilic pravastatin and lipophilic fluvastatin. The mRNA expression levels of possible drug transporters for statins were also examined in these cells using reverse transcriptase-PCR. KEY RESULTS In the skeletal myofibres, both pravastatin and fluvastatin induced vacuolation and cell death, whereas in the mononuclear cells only fluvastatin, but not pravastatin, was toxic. mRNA of the organic anion transporting polypeptides (Oatp) 1a4 and Oatp2b1 were expressed in the skeletal myofibres, but not in mononucleate cells. Estrone-3-sulphate, a substrate for Oatps, attenuated the effects of pravastatin and fluvastatin in skeletal myofibres; p-aminohippuric acid, a substrate for the organic anion transporters (Oats), but not Oatps, failed to do so. CONCLUSIONS AND IMPLICATIONS The statin transporters Oatp1a4 and Oatp2b1 are expressed in rat skeletal myofibres, but not in satellite cells, fibroblasts or in L6 myoblasts. This is probably why hydrophilic pravastatin affects skeletal muscle, but not skeletal myoblasts.
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Affiliation(s)
- K Sakamoto
- Department of Pharmacology, School of Medicine, Fukushima Medical University, Fukushima, Japan.
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Jacobson TA. Combination lipid-lowering therapy with statins: safety issues in the postcerivastatin era. Expert Opin Drug Saf 2003; 2:269-86. [PMID: 12904106 DOI: 10.1517/14740338.2.3.269] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Combination lipid-altering regimens represent an emerging clinical paradigm to meet increasingly stringent consensus lipoprotein targets for coronary prevention. This practice, together with escalating prevalences of coronary artery disease in certain ageing (western industrial) populations, polypharmacy in the elderly and the recent voluntary market withdrawal of cerivastatin, warrants a re-examination of the safety profiles of 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors (i.e., statins). These agents are exceedingly well-tolerated in the vast majority of patients, very infrequently precipitating musculoskeletal symptoms and/or signs. Statins vary in their pharmacological profiles, leading to distinct levels of systemic exposure and capacities to penetrate skeletal myocytes. Pharmacokinetic interactions with certain agents increase the likelihood of statin-induced myopathy and, in exceedingly rare instances, potentially fatal rhabdomyolysis with myoglobinuria and renal failure. As with other medical decisions, the anticipated benefits of long-term statin therapy, with or without other lipid-altering agents, need to be weighed against the prospects of clinically significant drug interactions. In clinical trials and postmarketing surveillance, the two statins that are not metabolised by the cytochrome P450 3A4 system (fluvastatin and pravastatin) have exhibited very low propensities to elicit myopathy when combined with other agents. These agents should be considered initially when contemplating combination lipid-lowering regimens for coronary prevention.
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Affiliation(s)
- Terry A Jacobson
- Office of Health Promotion and Disease Prevention, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30303, USA.
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Abstract
The 3-hydroxy-3-methyl coenzyme A (HMG-CoA) reductase inhibitors or statins, specifically inhibit the enzyme HMG-CoA in the liver, thereby inhibiting the rate limiting step in cholesterol biosynthesis and so reducing plasma cholesterol levels. Numerous studies have consistently demonstrated that cholesterol lowering with statin therapy reduces morbidity and mortality from coronary heart disease, whilst recent evidence has demonstrated that benefits of statin therapy may also extend into stroke prevention. Since hypercholesterolaemia is a chronic condition, the long-term safety and tolerability of these agents is an important issue. Numerous large-scale clinical trials have consistently demonstrated a positive safety and tolerability profile for statins. Hepatic, renal and muscular systems are rarely affected during statin therapy, with adverse reactions involving skeletal muscle being the most common, ranging from mild myopathy to myositis and occasionally to rhabdomyolysis and death. Postmarketing data supports the positive safety and tolerability profile of statins, with an overall adverse event frequency of less than 0.5% and a myotoxicity event rate of less than 0.1%. The recent withdrawal of cerivastatin from the world market due to deaths from rhabdomyolysis has, however, focused attention on the risk of adverse events and in particular myotoxicity associated with statins. Indeed, initial clinical trial data supports postmarketing data, demonstrating a higher incidence of myotoxicity associated with cerivastatin, particularly when used in combination with fibrates. The potential mechanisms underlying statin-induced myotoxicity are complex with no clear consensus of opinion. Candidate mechanisms include intracellular depletion of essential metabolites and destabilisation of cell membranes, resulting in increased cytotoxicity. Cytochrome P450 3A4 is the main isoenzyme involved in statin metabolism. Reduced activity of this enzyme due to either reduced expression or inhibition by other drugs prescribed concomitantly such as cyclosporin or itraconazole may increase drug bioavailability and the risk of myotoxicity. Such factors may partly account for the interindividual variability in susceptibility to statin-induced myotoxicity, although other as of yet unclarified, genetic factors may also be involved. The risk of rhabdomyolysis is increased with combination fibrate-statin therapy, with initial evidence suggesting that gemfibrozil-statin combination may particularly increase the risk of myotoxicity, with pharmacodynamic as well as pharmacokinetic mechanisms being involved.
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Affiliation(s)
- Marc Evans
- University Hospital of Wales, Heath Park, Cardiff, Wales
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Abstract
The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors specifically inhibit HMG-CoA reductase in the liver, thereby inhibiting the biosynthesis of cholesterol. These drugs significantly reduce plasma cholesterol level and long term treatment reduces morbidity and mortality associated with coronary heart disease. The tolerability of these drugs during long term administration is an important issue. Adverse reactions involving skeletal muscle are not uncommon, and sometimes serious adverse reactions involving skeletal muscle such as myopathy and rhabdomyolysis may occur, requiring discontinuation of the drug. Occasionally, arthralgia, alone or in association with myalgia, has been reported. In this article we review scientific data provided via Medline, adverse drug reaction case reports from the Swedish Drug Information System (SWEDIS) and the World Health Organization's International Drug Information System (INTDIS) database, focusing on HMG-CoA reductase inhibitor-related musculoskeletal system events. Cytochrome P450 (CYP) 3A4 is the main isoenzyme involved in the metabolic transformation of HMG-CoA reductase inhibitors. Individuals with both low hepatic and low gastrointestinal tract levels of CYP3A4 expression may be at in increased risk of myotoxicity due to potentially higher HMG-CoA reductase inhibitor plasma concentrations. The reported incidence of myotoxic reactions in patients treated with this drug class varies from 1 to 7% and varies between different agents. The risk of these serious adverse reactions is dose-dependent and may increase when HMG-CoA reductase inhibitors are prescribed concomitantly with drugs that inhibit their metabolism, such as itraconazole, cyclosporin, erythromycin and nefazodone. Electrolyte disturbances, infections, major trauma, hypoxia as well as drugs of abuse may increase the risk of myotoxicity. It is important that the potentially serious adverse reactions are recognised and correctly diagnosed so that the HMG-CoA reductase inhibitor may at once be withdrawn to prevent further muscular damage.
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Affiliation(s)
- M Ucar
- Division of Clinical Pharmacology, Norrland University Hospital, Umeå, Sweden.
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Pacifici GM, Viani A. Methods of determining plasma and tissue binding of drugs. Pharmacokinetic consequences. Clin Pharmacokinet 1992; 23:449-68. [PMID: 1458763 DOI: 10.2165/00003088-199223060-00005] [Citation(s) in RCA: 174] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The available techniques for the investigation of drug binding to plasma and tissues protein are reviewed and the advantages and disadvantages of the various techniques stated. A comparison of different plasma protein binding techniques is made which shows that the size of the unbound fraction of drug may be influenced by the method used. Protein binding may be assayed by methods including equilibrium dialysis, ultrafiltration, ultracentrifugation, gel filtration, binding to albumin microspheres and circular dichroism. Tissue binding techniques can involve testing binding to isolated organs, tissue slices, homogenates and isolated subcellular particles. Details of the available methods to compute pharmacokinetic constants are given. Stereoselective binding has been investigated for a limited number of drugs and the difference in the binding of 2 enantiomers is usually modest. The measurement of the binding constants is often required to characterise the drug-protein interaction. Mathematical and graphical methods to compute the pharmacokinetic parameters are discussed. The implications of binding on the volume of distribution and clearance of drugs are examined.
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Affiliation(s)
- G M Pacifici
- Department of Biomedicine, University of Pisa Medical School, Italy
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Tissue Binding versus Plasma Binding of Drugs: General Principles and Pharmacokinetic Consequences. ADVANCES IN DRUG RESEARCH 1991. [DOI: 10.1016/b978-0-12-013320-8.50006-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Abstract
For a series of ten drugs with different physicochemical properties, binding to human skin (epidermis and corium) was determined. Epidermis was obtained by suction blistering, and corium was sliced with a microtome (0.2 mm). Binding experiments were performed in dialysis chambers, containing labelled drug solutions. All drugs investigated were bound to epidermis and corium. With one exception, epidermal drug binding was significantly higher than corial binding. Nevertheless, a good correlation between binding of drugs to both skin fractions could be found. In a range from 10(-7) to 10(-3) mol L-1 binding of drugs to both skin fractions is linear and not saturable. A good correlation was found between binding and lipophilicity of drugs, determined as the partition coefficients between an organic phase (octanol or heptane) and phosphate buffer of pH 7.0. The results show that binding to epidermis and corium is not saturable and depends on lipophilicity of drugs, indicating unspecific binding. Further binding experiments were performed with lipid-depleted tissue. Since drug binding to lipid-depleted samples and control samples differ only to a moderate extent, it is suggested, that tissue lipids play a marginal role on drug binding. Hence, drugs are bound to human skin by other components like proteins.
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Affiliation(s)
- K Walter
- Walther Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, FRG
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Nordberg G, Borg L, Hedner T, Mellstrand T. CSF and plasma pharmacokinetics of intramuscular morphine. Eur J Clin Pharmacol 1985; 27:677-81. [PMID: 3987773 DOI: 10.1007/bf00547048] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Morphine concentrations in plasma and cerebrospinal fluid (CSF) were measured in 58 elderly patients after intramuscular administration of 10 mg morphine. The assay employed gas chromatography with electron capture detection. From 49 of the patients undergoing urological procedures plasma and lumbar CSF samples were obtained simultaneously as spinal analgesia was given, and in addition, repeated venous samples were obtained over 4 hours from 35 of the patients. A plasma-morphine concentration vs time plot was drawn from the mean values and a CSF-morphine vs time plot was calculated by pooling individual CSF concentrations and using the sliding mean technique. The individual CSF/plasma-morphine concentration ratio vs time was also plotted. In addition, 2 or 3 CSF and plasma samples were collected simultaneously from 3 patients undergoing thoracotomy. Large interindividual variation in the CSF concentration was found. The peak CSF level was reached after 3 h and, following pseudoequilibrium, CSF-morphine levels appeared only slightly lower than those found in plasma. The availability to spinal CSF amounted to no more than 0.005% of the administered dose. CSF-morphine concentrations were not related to plasma protein or albumin concentrations.
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Gabrielsson JL, Paalzow LK. A physiological pharmacokinetic model for morphine disposition in the pregnant rat. JOURNAL OF PHARMACOKINETICS AND BIOPHARMACEUTICS 1983; 11:147-63. [PMID: 6886971 DOI: 10.1007/bf01061846] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A physiological model was used to examine the disposition of morphine in the pregnant rat. In the model was incorporated an expression of both a linear and a nonlinear binding term of morphine to the maternal muscular tissue. Furthermore, the experimental data suggested that a diffusion-limited transport of morphine occurred across the placenta. Morphine showed a relatively high partition into the maternal kidney and muscle tissues. The concentration of morphine in the foetus was about 1.5 times higher than that of the maternal plasma, whereas the foetal brain concentration was about 4 times higher than that of the maternal plasma. The influence on morphine disposition by changes in both the tissue binding of the maternal muscle and the placental plasma flow was explored by model simulations. Due to the diffusion-limited transport of morphine across the placenta, a change in the placental plasma flow would only have an effect on the concentration-time profile of morphine in the foetal tissues if the plasma flow approached and became less than the diffusion clearance across the placenta. An increase in the partition of morphine into the maternal muscle produced an increase in the terminal half-life in all tissues including the foetus.
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TOUTAIN PL, ALVINERIE M, RUCKEBUSCH Y. Residue profile of phenylbutazone in the rabbit. A comparative evaluation by tissue kinetics prior to and post mortem. J Vet Pharmacol Ther 1980. [DOI: 10.1111/j.1365-2885.1980.tb00490.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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