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Parrot M, Yathavan B, Averin O, Hoggard L, Rower JE, Voight M, Greene D, Tarrell A, Whelan A, Ghandehari H, Murphy N, Yellepeddi V. Clinical pharmacokinetics of atropine oral gel formulation in healthy volunteers. Clin Transl Sci 2024; 17:e13753. [PMID: 38465519 PMCID: PMC10926053 DOI: 10.1111/cts.13753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 02/01/2024] [Accepted: 02/14/2024] [Indexed: 03/12/2024] Open
Abstract
Sialorrhea or drooling is a common problem in children and adults with neurodevelopmental disorders. It can negatively impact the quality of life due to its physical and psychological manifestations. Providers commonly prescribe atropine eye drops for topical administration to the oral mucosa, as an off-label treatment to manage sialorrhea. However, the off-label use of atropine eye drops can be associated with medication and dosing errors and systemic side effects. To address these limitations of treatment, we developed a mucoadhesive topical oral gel formulation of atropine as an alternative route to off-label administration of atropine eye drops. In this clinical pharmacokinetic (PK) study, we evaluated the safety and PK of atropine gel (0.01% w/w) formulation after single-dose administration to the oral mucosa in 10 healthy volunteers. The PK data showed that after topical administration to the oral mucosa, atropine followed a two-compartment PK profile. The maximum plasma concentration and area under the curve extrapolated to infinite time were 0.14 ng/mL and 0.74 h·ng·mL-1 , respectively. The absorption rate constant calculated by the compartmental analysis was 0.4 h-1 . Safety parameters, such as heart rate, blood pressure, and oxygen saturation, did not significantly change before and after administration of the gel formulation, and no adverse events were observed in all participants who received atropine gel. These data indicate that atropine gel formulation has a satisfactory PK profile, is well-tolerated at the dose studied, and can be further considered for clinical development as a drug product to treat sialorrhea.
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Affiliation(s)
- Madison Parrot
- Division of Clinical Pharmacology, Department of Pediatrics, Spencer Fox Eccles School of MedicineUniversity of UtahSalt Lake CityUtahUSA
- Department of Molecular Pharmaceutics, Utah Center for Nanomedicine, College of PharmacyUniversity of UtahSalt Lake CityUtahUSA
| | - Bhuvanesh Yathavan
- Department of Molecular Pharmaceutics, Utah Center for Nanomedicine, College of PharmacyUniversity of UtahSalt Lake CityUtahUSA
| | - Olga Averin
- Department of Pharmacology and Toxicology and Center for Human ToxicologyUniversity of UtahSalt Lake CityUtahUSA
| | - Logan Hoggard
- Department of Pharmacology and Toxicology and Center for Human ToxicologyUniversity of UtahSalt Lake CityUtahUSA
| | - Joseph E. Rower
- Department of Pharmacology and Toxicology and Center for Human ToxicologyUniversity of UtahSalt Lake CityUtahUSA
| | - Michael Voight
- Investigational Drug Service, Pharmacy Services, University of Utah HospitalSalt Lake CityUtahUSA
| | - Danielle Greene
- Division of Clinical Pharmacology, Department of Pediatrics, Spencer Fox Eccles School of MedicineUniversity of UtahSalt Lake CityUtahUSA
| | - Ariel Tarrell
- Division of Clinical Pharmacology, Department of Pediatrics, Spencer Fox Eccles School of MedicineUniversity of UtahSalt Lake CityUtahUSA
| | - Aviva Whelan
- Division of Clinical Pharmacology, Department of Pediatrics, Spencer Fox Eccles School of MedicineUniversity of UtahSalt Lake CityUtahUSA
| | - Hamidreza Ghandehari
- Department of Molecular Pharmaceutics, Utah Center for Nanomedicine, College of PharmacyUniversity of UtahSalt Lake CityUtahUSA
| | - Nancy Murphy
- Division of Complex Care, Department of PediatricsUniversity of Utah HealthSalt Lake CityUtahUSA
| | - Venkata Yellepeddi
- Division of Clinical Pharmacology, Department of Pediatrics, Spencer Fox Eccles School of MedicineUniversity of UtahSalt Lake CityUtahUSA
- Department of Molecular Pharmaceutics, Utah Center for Nanomedicine, College of PharmacyUniversity of UtahSalt Lake CityUtahUSA
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Ekstrand C, Michanek P, Gehring R, Sundell A, Källse A, Hedeland M, Ström L. Plasma atropine concentrations associated with decreased intestinal motility in horses. Front Vet Sci 2022; 9:951300. [PMID: 36118347 PMCID: PMC9478751 DOI: 10.3389/fvets.2022.951300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 07/25/2022] [Indexed: 12/02/2022] Open
Abstract
Introduction Atropine is an essential part of the treatment protocol for equine uveitis. Topical atropine administration has been associated with decreased intestinal motility and abdominal pain in horses. Experimental studies have indicated that frequent dosing is associated with a higher risk than dosing every 6 h. Unfortunately, no quantitative pharmacodynamic data for inhibition of the equine gut are published. Materials and methods Eight standardbred horses were assigned to receive either atropine or saline (control) to be infused over 30 min in a two-treatment cross-over design. Atropine concentrations in plasma were measured using ultra-high-performance liquid chromatography–tandem mass spectrometry. Intestinal motility was measured using borborygmi frequency and electrointestinography (EIG). Experimental data were analyzed using a non-linear mixed effects model. The model was then used to simulate different dosing regimens. Results Atropine significantly decreased borborygmi response and EIG response. Six horses developed clinical signs of abdominal pain. The pharmacokinetic typical values were 0.31, 1.38, 0.69, and 1.95 L/kg·h for the volumes of the central, the highly perfused, the scarcely perfused compartments, and the total body clearance, respectively. The pharmacodynamic typical values were 0.31 μg/L and 0.6 and 207 nV27 cpm for the plasma concentration at 50% of the maximum response and the maximum response and the baseline of cecal EIG response, respectively. Six different dosing regimens of topical atropine sulfate to the eye (0.4 and 1 mg every hour, every 3 h, and every 6 h) were simulated. Conclusion The IV PK/PD data coupled with simulations predict that administration of 1 mg of topical atropine sulfate administered to the eye every hour or every 3 h will lead to atropine accumulation in plasma and decreased intestinal myoelectric activity. Administration every 6 h predicted a safe dosing regimen in full-sized horses. Clinical studies would be valuable to confirm the conclusions. For smaller equids and horses put at risk for colic due to othercauses, droplet bottles that deliver 40 μl of 1% atropine sulfate per drop or less may be used to lower the risk further.
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Affiliation(s)
- Carl Ekstrand
- Department of Biomedicine and Veterinary Public Health, Division of Pharmacology and Toxicology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Peter Michanek
- Department of Biomedicine and Veterinary Public Health, Division of Pharmacology and Toxicology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ronette Gehring
- Department of Biomedicine and Veterinary Public Health, Division of Pharmacology and Toxicology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Department of Population Health Sciences, Division of Veterinary and Comparative Pharmacology, Utrecht University, Utrecht, Netherlands
- *Correspondence: Ronette Gehring
| | - Anna Sundell
- Department of Biomedicine and Veterinary Public Health, Division of Pharmacology and Toxicology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Annika Källse
- Department of Biomedicine and Veterinary Public Health, Division of Pharmacology and Toxicology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Mikael Hedeland
- Department of Medicinal Chemistry, Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - Lena Ström
- Department of Clinical Sciences, Division of Large Animal Surgery, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Ström L, Dalin F, Domberg M, Stenlund C, Bondesson U, Hedeland M, Toutain PL, Ekstrand C. Topical ophthalmic atropine in horses, pharmacokinetics and effect on intestinal motility. BMC Vet Res 2021; 17:149. [PMID: 33827566 PMCID: PMC8028730 DOI: 10.1186/s12917-021-02847-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 03/22/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Topical ophthalmic atropine sulfate is an important part of the treatment protocol in equine uveitis. Frequent administration of topical atropine may cause decreased intestinal motility and colic in horses due to systemic exposure. Atropine pharmacokinetics are unknown in horses and this knowledge gap could impede the use of atropine because of the presumed risk of unwanted effects. Additional information could therefore increase safety in atropine treatment. RESULTS Atropine sulfate (1 mg) was administered in two experiments: In part I, atropine sulfate was administered intravenously and topically (manually as eye drops and through a subpalpebral lavage system) to six horses to document atropine disposition. Blood-samples were collected regularly and plasma was analyzed for atropine using UHPLC-MS/MS. Atropine plasma concentration was below lower limit of quantification (0.05 μg/L) within five hours, after both topical and IV administration. Atropine data were analyzed by means of population compartmental modeling and pharmacokinetic parameters estimated. The typical value was 1.7 L/kg for the steady-state volume of distribution. Total plasma clearance was 1.9 L/h‧kg. The bioavailability after administration of an ophthalmic preparation as an eye drop or topical infusion were 69 and 68%, respectively. The terminal half-life was short (0.8 h). In part II, topical ophthalmic atropine sulfate and control treatment was administered to four horses in two dosing regimens to assess the effect on gastro-intestinal motility. Borborygmi-frequency monitored by auscultation was used for estimation of gut motility. A statistically significant decrease in intestinal motility was observed after administration of 1 mg topical ophthalmic atropine sulfate every three hours compared to control, but not after administration every six hours. Clinical signs of colic were not observed under any of the treatment protocols. CONCLUSIONS Taking the plasma exposure after topical administration into consideration, data and simulations indicate that eye drops administrated at a one and three hour interval will lead to atropine accumulation in plasma over 24 h but that a six hour interval allows total washout of atropine between two topical administrations. If constant corneal and conjunctival atropine exposure is required, a topical constant rate infusion at 5 μg/kg/24 h offers a safe alternative.
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Affiliation(s)
- L Ström
- Department of Clinical Sciences, Division of Large Animal Surgery, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - F Dalin
- Department of Clinical Sciences, Division of Large Animal Surgery, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - M Domberg
- Department of Clinical Sciences, Division of Large Animal Surgery, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - C Stenlund
- Department of Clinical Sciences, Division of Large Animal Surgery, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - U Bondesson
- Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute, Uppsala, Sweden.,Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - M Hedeland
- Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute, Uppsala, Sweden.,Department of Medicinal Chemistry, Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - P-L Toutain
- INTHERES, Université de Toulouse, INRA, ENVT, Toulouse, France.,The Royal Veterinary College, University of London, London, UK
| | - C Ekstrand
- Department of Biomedicine and Veterinary Public Health, Division of Pharmacology and Toxicology, Swedish University of Agricultural Sciences, P.O. Box 7028, SE-750 07, Uppsala, Sweden.
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Synthesized atropine nanoparticles ameliorate airway hyperreactivity and remodeling in a murine model of chronic asthma. J Drug Deliv Sci Technol 2020. [DOI: 10.1016/j.jddst.2020.101507] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Huhle R, Siegert J, Wonka F, Schindler C, de Abreu MG, Koch T, Morgenstern U, Theilen H. Assessing the eligibility of a non-invasive continuous blood pressure measurement technique for application during total intravenous anaesthesia. ACTA ACUST UNITED AC 2016; 61:369-79. [PMID: 26859497 DOI: 10.1515/bmt-2015-0001] [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: 01/05/2015] [Accepted: 11/10/2015] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To assess the eligibility for replacement of invasive blood pressure as measured "within" the arterial vessel (IBP) with non-invasive continuous arterial blood pressure (cNIP) monitoring during total intravenous anaesthesia (TIVA), the ability of cNiP to track fast blood pressure changes needs to be quantified. A new method of statistical data analysis is developed for this purpose. METHODS In a pilot study on patients undergoing neurosurgical anaesthesia, mean arterial pressure MAPIBP measured with IBP was compared to MAPCNP measured by the CNAP Monitor 500 in ten patients (age: 63±13 a). Correlation analysis of changes of device differences ΔeMAP=ΔMAPCNP-ΔMAPIBP with changes of MAPIBP (ΔMAPIBP) during intervals of vasoactivity was conducted. An innovative technique, of linear trend analysis (LTA) applied to two signals, is described to perform this analysis without a priori knowledge of intervals of vasoactivity. RESULTS Analysis of ΔeMAP during vasoactivity revealed that ΔMAPCNP systematically underestimated ΔMAPIBP by 37%. This was confirmed in the complete data set using LTA technique showing a systematic, yet patient specific, underestimation in tracking ΔMAPIBP (16…120%). CONCLUSION The proposed LTA technique is able to detect systematic errors in tracking short-term blood pressure changes otherwise masked by established analysis. LTA may thus be a useful tool to assess the eligibility of cNIP to replace IBP during TIVA.
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Abstract
Anticholinergics, or antimuscarinic drugs, are drugs that competitively inhibit the action of acetylcholine at muscarinic receptors, leading to a blockade of the actions of the parasympathetic nervous system at sites where overactivity can lead to increased symptom burden. Successful blockade of the parasympathetic nervous system ultimately leads to decreased production of secretions in the salivary, bronchial, and gastrointestinal tracts. These effects are often used for several symptoms that originate due to parasympathetic nervous system overactivity, such as the "death rattle" and malignant bowel obstruction. Anticholinergic agents are divided into either tertiary amines or quaternary ammonium compounds, which differ in their ability to cross into the central nervous system. Quaternary compounds do not cross into the central nervous system and have a different adverse effect profile than the tertiary amines. The purpose of this review is to highlight anticholinergic agents, their pharmacology, and an evidence-based assessment of their role in palliative care.
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Affiliation(s)
- Eric Prommer
- Division of Hematology/Oncology, Mayo Clinic College of Medicine Mayo Clinic Hospital, Scottsdale, AZ 85054, USA.
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Moulton BC, Fryer AD. Muscarinic receptor antagonists, from folklore to pharmacology; finding drugs that actually work in asthma and COPD. Br J Pharmacol 2011; 163:44-52. [PMID: 21198547 DOI: 10.1111/j.1476-5381.2010.01190.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
In the lungs, parasympathetic nerves provide the dominant control of airway smooth muscle with release of acetylcholine onto M3 muscarinic receptors. Treatment of airway disease with anticholinergic drugs that block muscarinic receptors began over 2000 years ago. Pharmacologic data all indicated that antimuscarinic drugs should be highly effective in asthma but clinical results were mixed. Thus, with the discovery of effective β-adrenergic receptor agonists the use of muscarinic antagonists declined. Lack of effectiveness of muscarinic antagonists is due to a variety of factors including unwanted side effects (ranging from dry mouth to coma) and the discovery of additional muscarinic receptor subtypes in the lungs with sometimes competing effects. Perhaps the most important problem is ineffective dosing due to poorly understood differences between routes of administration and no effective way of testing whether antagonists block receptors stimulated physiologically by acetylcholine. Newer muscarinic receptor antagonists are being developed that address the problems of side effects and receptor selectivity that appear to be quite promising in the treatment of asthma and chronic obstructive pulmonary disease.
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Affiliation(s)
- Bart C Moulton
- Division Pulmonary and Critical Care Medicine, Oregon Health Sciences University, Portland, 97239, USA.
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Eyer P, Eddleston M, Thiermann H, Worek F, Buckley NA. Are we using the right dose? - a tale of mole and gram. Br J Clin Pharmacol 2008; 66:451-2. [PMID: 18662291 DOI: 10.1111/j.1365-2125.2008.03245.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Peter Eyer
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig Maximilians University, Munich, Germany.
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Paret G, Mazkereth R, Sella R, Almog S, Mayan H, Lotan D, Ben-Abraham R, Barzilay Z, Ezra D. Atropine pharmacokinetics and pharmacodynamics following endotracheal versus endobronchial administration in dogs. Resuscitation 1999; 41:57-62. [PMID: 10459593 DOI: 10.1016/s0300-9572(99)00031-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Emergency endotracheal and endobronchial drug administration provide an effective alternative for intravenous drug delivery during cardiopulmonary resuscitation. The purpose of the present study was to determine the immediate pharmacokinetic and pharmacodynamic properties of atropine following administration by either of these routes. Atropine (0.02 mg/kg) was given to seven anaesthetized mongrel dogs. Each dog was studied twice: once when atropine was injected into the endotracheal tube, and on another day when atropine was given via a flexible catheter wedged into a peripheral bronchus. Plasma atropine concentrations and blood gases were measured during 60 min following drug administration. Both routes of atropine administration differed significantly in three measures: the maximal atropine concentration (Cmax) was significantly higher with the endobronchial administration 40.0 +/- 7.8 ng/ml compared to 23.9 +/- 5 ng/ml endotracheally (P = 0.008); atropine's elimination (t1/2beta) half-life was significantly longer with the endobronchial route (39.3 +/- 5.2 min vs. 28.0 +/- 7.9 min; P = 0.05); Endobronchial administration resulted in an increase of 16% in heart rate, beginning immediately after drug delivery and peaking after 5 min. Other pharmacokinetic parameters were not significantly different. We conclude that endobronchial administration of atropine has a clear advantage over the endotracheal route.
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Affiliation(s)
- G Paret
- Pediatric Intensive Care Unit, Chaim Sheba Medical Center, Tel-Hashomer, Tel-Aviv, Israel
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Koprda V, Bohov P, Smisterová J, Boháčik L. Methods of assessment of atropine and scopolamine levels in transdermal permeation. J Radioanal Nucl Chem 1994. [DOI: 10.1007/bf02164737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Qiao GL, Fung KF. Pharmacokinetic-pharmacodynamic modelling of meperidine in goats (II): Modelling. J Vet Pharmacol Ther 1994; 17:127-34. [PMID: 8040932 DOI: 10.1111/j.1365-2885.1994.tb00222.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Simultaneous pharmacokinetic-pharmacodynamic (PK-PD) models of meperidine in goats were established by utilizing the P3 wave of the cerebral evoked potentials as an analgesic measurement. An effect compartment linked to the central compartment was postulated in the models. The hypothetical drug amount in the effect compartment was related to the observed analgesia through the Hill equation. After intramuscular (i.m., n = 16) and intravenous (i.v., n = 13) dosing (5 mg/kg), the elimination rate constants of meperidine in the effect compartment (Ke0) were 0.3744 +/- 0.2546 and 0.1123 +/- 0.0428 min-1, drug concentrations in the effect compartment generating half maximal analgesia (EC(50)) were 0.70 +/- 0.33 and 0.41 +/- 0.26 microgram/ml, the maximal effects (Emax) were 89.63 +/- 15.63 and 85.92 +/- 9.64%, and the Hill coefficients (S) were 2.61 +/- 1.21 and 2.37 +/- 1.15, respectively. Ke0 and EC(50) with i.m. dosing were significantly greater than with i.v. injection. However, administration route had no influence on S, Emax and the total amount of effect (AUE). The predicted peak effect (Emax) of 64.44 +/- 14.64 and 66.02 +/- 11.51% were achieved at 14.7 +/- 7.4 and 8.5 +/- 2.2 min after i.m. and i.v. dosing, respectively. Peak analgesia appeared much later than peak plasma concentration, but simultaneously with peak CSF level both after i.m. and i.v. dosing. An obvious hysteresis was demonstrated between plasma concentration and analgesic effect. This study demonstrates that meperidine analgesia can be predicted using a PK-PD model, but not by PK data alone. Both i.m. and i.v. administration routes were evaluated kinetically and dynamically.
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Affiliation(s)
- G L Qiao
- Laboratory of Veterinary Pharmacology, South China Agricultural University, Guangzhou
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12
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Jaklitsch RR, Westenskow DR. A simulation of neuromuscular function and heart rate during induction, maintenance, and reversal of neuromuscular blockade. J Clin Monit Comput 1990; 6:24-38. [PMID: 2404085 DOI: 10.1007/bf02832179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We developed a two-compartment model to simulate neuromuscular function and heart rate following the administration of four nondepolarizing neuromuscular blocking agents (atracurium, vecuronium, pancuronium, and d-tubocurarine), three neuromuscular block reversal agents (edrophonium, neostigmine, and pyridostigmine), and two anticholinergic agents (atropine and glycopyrrolate). Twitch depression, train-of-four ratio, and heart rate were modeled during fentanyl, halothane, enflurane, or isoflurane anesthesia, optionally supplemented with nitrous oxide. Simulation results, compared with published values for each drug, fell within the clinical accuracy range (onset time 6.1 +/- 3.9% [mean +/- SEM]; duration, 1.7 +/- 3.5%, 50% effective dose, 0.5 +/- 5.7%; and 95% effective dose, 2.1 +/- 1.1%). The simulation graphically demonstrates the pharmacokinetics, pharmacodynamics, and interactions between neuromuscular blocking agents, reversal agents, and anticholinergic agents. During a simulation, the need for frequent monitoring and repeated delivery of a neuromuscular blocking agent to keep neuromuscular blockade stable becomes apparent, especially with the intermediate-acting neuromuscular blocking agents. When inhalational agents are given concomitantly, the task becomes even more difficult, since potentiation changes with anesthetic uptake. Recurarization, tachycardia, or bradycardia may be seen with the simulation if an improper drug regimen is followed. Concurrent simulation of two identical patients allows comparison of different modes of administration, choice of anesthetic agents, and drug doses.
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Affiliation(s)
- R R Jaklitsch
- Department of Anesthesiology, University of Utah, Salt Lake City 84132
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Abstract
The dose-response relationship and the doses of atropine required to prevent neostigmine from lowering heart rates below baseline in 50 per cent (ED50) and 95 percent (ED95) of patients after antagonism of pancuronium-induced neuromuscular blockade were determined in 70 patients with neostigmine-atropine mixtures. Neostigmine 0.04 mg.kg-1 (group A, n = 35) or 0.06 mg.kg-1 (group B, n = 35) was randomly mixed with one of seven doses of atropine (ranging from 0.014 to 0.04 mg.kg-1) in group A and from 0.02 to 0.04 mg.kg-1 in group B), with dose-response curves for atropine being constructed for both groups 5 and 10 min after injection of the mixture. These dose-response curves were found to be parallel in both groups. The calculated ED50 and ED95 values of atropine were similar in both groups. The estimated ED50 doses of atropine in groups A and B at 5 min were 0.031 and 0.033 mg.kg-1 respectively, and at 10 min the ED50 doses were 0.037 and 0.037 mg.kg-1 respectively. The calculated ED95 doses of atropine in groups A and B at 5 min were 0.05 and 0.046 mg.kg-1, and at 10 min the ED95 doses were also similar, being 0.06 and 0.055 mg.kg-1 respectively. Under the conditions employed in this study it would seem that in order to prevent late reductions in heart rates, the appropriate doses of atropine when used with neostigmine should be greater than that commonly used.
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Affiliation(s)
- M Naguib
- Department of Anaesthesiology, King Saud University, King Khalid University Hospital, Riyadh, Saudi Arabia
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Friedl KE, Hannan CJ, Mader TH, Patience TH, Schadler PW. Effect of eye color on heart rate response to intramuscular administration of atropine. JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM 1988; 24:51-6. [PMID: 3209800 DOI: 10.1016/0165-1838(88)90134-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Melanin has been previously shown to modify the mydriatic response to atropine instillation. Skin and iris pigmentation has also been shown to modify aspects of the heart rate response to injected atropine, although these observations have been generally overlooked. In this study, 20 healthy non-smoker male subjects, ages 20-30 years, were injected by two different automatic injector devices and the mydriatic and heart rate responses in the first 90 min were reported. The group included 8 brown-eyed, 4 hazel-eyed, and 8 blue-eyed subjects. Although there were differences in the rate of atropine delivery between the two injection devices, the heart rate responses were independently modified by eye color to a magnitude of difference as great as the differences between injectors. Subjects with more pigmented irides (brown-eyed) showed a more rapid rise in heart rate compared to less pigmented irides (hazel-eyed and blue-eyed subjects). Following injection by the device with a slower atropine absorption rate, these differences were particularly enhanced and an abbreviated bradycardic phase of the heart rate response was observed for the brown-eyed subjects. This observation confirms earlier reports and suggests the possibility of an interference by melanin (in the iris or elsewhere) in atropine accessibility to selected muscarinic target sites.
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Affiliation(s)
- K E Friedl
- Department of Clinical Investigation, Madigan Army Medical Center, Tacoma, WA 98431-5454
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Kanto J, Klotz U. Pharmacokinetic implications for the clinical use of atropine, scopolamine and glycopyrrolate. Acta Anaesthesiol Scand 1988; 32:69-78. [PMID: 3279717 DOI: 10.1111/j.1399-6576.1988.tb02691.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Several specific and sensitive new methods for determining atropine and its metabolites in biological fluids have increased the possibility to characterise the pharmacokinetic properties of this antimuscarinic agent. Following i.v. injection, atropine disappears very quickly from the circulation, resembling its fast onset of action. Age, but not sex, appears to have a clear effect on its kinetics, explaining at least partly the higher sensitivity of very young and very old patients to this anticholinergic agent. Following i.m. or oral atropine administration, typical anticholinergic effects coincide quite well with the absorption rate of the drug, indicating that the premedication should be given about 1 and 2 h before induction of anaesthesia. A sufficient absorption after rectal administration offers an alternative treatment, especially in children. Differing from its placental transfer, atropine has a delayed and incomplete lumbar cerebrospinal fluid penetration, indicating a fundamental difference between these two biological membranes. Oropharyngeally administered atropine has a very variable absorption, but inhaled or intratracheally given drug has produced interesting new results, e.g. pulmonary atropine administration appears to have clinical significance in special situations, such as cardiac arrest and organophosphate poisoning (military personnel). Depending on the method used, different data on the metabolism and excretion for atropine have been reported and therefore further studies are needed in this respect. The pharmacokinetics of scopolamine and glycopyrrolate and their relation to clinical response are poorly understood.
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Affiliation(s)
- J Kanto
- Department of Anaesthesiology, Turku University, Finland
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Koller EA, Drechsel S, Hess T, Macherel P, Boutellier U. Effects of atropine and propranolol on the respiratory, circulatory, and ECG responses to high altitude in man. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1988; 57:163-72. [PMID: 3349981 DOI: 10.1007/bf00640657] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In order to analyze the respiratory, cardiovascular, and ECG responses to acute hypoxic hypoxia, three experimental series were carried out in a randomized manner on 11 healthy, unacclimatized volunteers at rest during standardized stepwise exposure to 6000 m (PAO2 35.2 +/- 2.9 mmHg/4.7 +/- 0.4 kPa) in a low-pressure chamber a) without (control), b) with propranolol, and c) with atropine combined with propranolol. The results show that hypoxic hyperventilation and alveolar gases are not affected by activation of the sympatho-adrenal axis or by parasympathetic withdrawal. Sympathetic activity, however, increases heart rate, stroke volume (pulse pressure), estimated cardiac output and systolic blood pressure, whereas decreased parasympathetic activity increases heart rate and estimated cardiac output, but lowers stroke volume. The fall in peripheral resistance, observed during progressive hypoxia in all three groups, is thought to be due to hypoxia-induced depression of the vasomotor center. At altitude catecholamine secretion and vagal withdrawal synergistically account in the ECG for the R-R shortening, the relative Q-T lengthening, the elevation of the P wave and the ST-T flattening. Probable direct hypoxic effects on the heart are the increase in P-Q duration and the minor but still significant depression of the T wave. It is concluded that at altitude increased sympatho-adrenal and decreased parasympathetic activity is without effect on hypoxic hyperventilation, but accounts for most of the cardiovascular and ECG changes. Diminution of sympathetic activity and imminent vagotonia arising after acute ascent to 6000 m probably reflect hypoxia of the central nervous system.
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Affiliation(s)
- E A Koller
- Department of Physiology, University of Zurich, Switzerland
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