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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Utvärdering av prehospital vård och behandling av hjärtinfarktpatienter med tromboshämmande läkemedel : En fall/kontroll studie efter införandet av ny behandlingsrutin / Evaluation of pre-hospital care and treatment with thrombosis inhibiting medicine for patients with myocardial infarction : A case/control study after the introduction of a new method of treatment

Wasniowski, Benjamin, Melin, Carina January 2008 (has links)
<p><strong>Introduktion: </strong>Akut hjärtinfarkt är en vanlig dödsorsak. Viktigaste behandlingsinsatsen vid hjärtinfarkt är att snabbt öppna det ockluderade kranskärlet genom primär Perkutan Coronar Intervention (PCI). Viktigt är även att behandlingen förhindrar att kärlet åter ockluderar. Detta görs genom att behandla med det blodproppshämmande och kärlpåverkande läkemedlet Clopidogrel. Enligt en ny behandlingsrutin ges Clopidogrel redan i ambulansen vid konstaterande av hjärtinfarkt för att uppnå effekt så fort som möjligt. <strong>Syfte:</strong><em> </em>Syftet var att undersöka om prehospital behandling med Clopidogrel leder till god vård i form av snabbare PCI-behandling, kortare vårdtid, färre medicinska komplikationer, färre komplikationer relaterade till omvårdnad för patienter med ST-höjningsinfarkt samt undersöka vilka omvårdnadsåtgärder som dokumenterats vid förekomst av komplikationer. <strong>Metod: </strong>En retrospektiv fall/kontroll studie utfördes där patientjournaler och databasutskrifter från angiolaboratoriets interna register undersöktes. Studien inkluderade patienter som fått PCI-behandling mellan 1 juni 2006 och 1 februari 2008 och som inkommit med ambulans direkt till angiolaboratoriet.<strong> </strong>I fallgruppen (n = 37) ingick de som fått Clopidogrel i ambulans och i kontrollgruppen (n = 83) de som fått Clopidogrel i direkt anslutning till PCI-behandlingen.  <strong>Resultat: </strong>En skillnad uppmättes mellan grupperna för tiden mellan ankomst till angiolaboratoriet och påbörjad PCI-behandling.<strong> </strong>En förlängning av tiden uppmättes i fallgruppen (p = 0,05). Det är oklart i vilken mån prehospital behandling med Clopidogrel förbättrar utfallet vad gäller vårdtid, medicinska komplikationer samt komplikationer relaterade till omvårdnad för patienter med ST-höjningsinfarkt. Omvårdnadsåtgärder var bristfälligt dokumenterade. Studiens omfattning är begränsad vilket gör att resultaten bör beaktas med försiktighet. <strong>Konklusion:</strong> Fler studier behövs för att undersöka värdet av prehospital behandling med Clopidogrel.</p> / <p><strong>Introduction:</strong> Acute myocardial infarction is a very common cause of death. The most important treatment for myocardial infarction is to rapidly open the occluded coronary artery by Perkutan Coronar Intervention (PCI). It is also important that treatment prevents re-occlusion of the coronary artery. This is done by treatment with Clopidogrel which is a blood thrombosis inhibiting and vessel affective medicine. According to a new guideline Clopidogrel should be given already in the ambulance when myocardial infarction is established in order to achieve effect as quickly as possible.<strong>Purpose:</strong><em> </em>The purpose of the study was to examine if pre-hospital treatment with Clopidogrel leads to good care in the form of quicker PCI-treatment, reduced length of stay, fewer medical complications, fewer complications related to nursing for patients with STEMI and to examine what kind of nursing care was documented when complications occurred. <strong>Method: </strong>A retrospective case/control study was carried out where patient journals and database prints from the angiolaboratory internal registry were examined. The study included patients who received PCI-treatment between 1 June 2006 and 1 February 2008 and who arrived with ambulance directly to the angiolaboratory. The case group (n = 37) included patients that received Clopidogrel during ambulance transport and the control group (n = 83) included patients who received Clopidogrel in direct proximity to the PCI-treatment.<strong>Results: </strong>A difference was found between the groups for the time between arrival at the angio-laboratory and the start of PCI-treatment. The time was extended in the case group (p = 0,05). It is uncertain if pre-hospital treatment with Clopidogrel improves the length of hospital stay, numbers of medical complications and complications related to nursing for STEMI-patients. Nursing treatment was poorly documented. The range of the study is limited, therefore the results should be considered carefully. </p><p><strong>Conclusion:</strong> Further studies needs to be carried out to examine the value of pre-hospital treatment with Clopidogrel.</p>
2

Utvärdering av prehospital vård och behandling av hjärtinfarktpatienter med tromboshämmande läkemedel : En fall/kontroll studie efter införandet av ny behandlingsrutin / Evaluation of pre-hospital care and treatment with thrombosis inhibiting medicine for patients with myocardial infarction : A case/control study after the introduction of a new method of treatment

Wasniowski, Benjamin, Melin, Carina January 2008 (has links)
Introduktion: Akut hjärtinfarkt är en vanlig dödsorsak. Viktigaste behandlingsinsatsen vid hjärtinfarkt är att snabbt öppna det ockluderade kranskärlet genom primär Perkutan Coronar Intervention (PCI). Viktigt är även att behandlingen förhindrar att kärlet åter ockluderar. Detta görs genom att behandla med det blodproppshämmande och kärlpåverkande läkemedlet Clopidogrel. Enligt en ny behandlingsrutin ges Clopidogrel redan i ambulansen vid konstaterande av hjärtinfarkt för att uppnå effekt så fort som möjligt. Syfte: Syftet var att undersöka om prehospital behandling med Clopidogrel leder till god vård i form av snabbare PCI-behandling, kortare vårdtid, färre medicinska komplikationer, färre komplikationer relaterade till omvårdnad för patienter med ST-höjningsinfarkt samt undersöka vilka omvårdnadsåtgärder som dokumenterats vid förekomst av komplikationer. Metod: En retrospektiv fall/kontroll studie utfördes där patientjournaler och databasutskrifter från angiolaboratoriets interna register undersöktes. Studien inkluderade patienter som fått PCI-behandling mellan 1 juni 2006 och 1 februari 2008 och som inkommit med ambulans direkt till angiolaboratoriet. I fallgruppen (n = 37) ingick de som fått Clopidogrel i ambulans och i kontrollgruppen (n = 83) de som fått Clopidogrel i direkt anslutning till PCI-behandlingen.  Resultat: En skillnad uppmättes mellan grupperna för tiden mellan ankomst till angiolaboratoriet och påbörjad PCI-behandling. En förlängning av tiden uppmättes i fallgruppen (p = 0,05). Det är oklart i vilken mån prehospital behandling med Clopidogrel förbättrar utfallet vad gäller vårdtid, medicinska komplikationer samt komplikationer relaterade till omvårdnad för patienter med ST-höjningsinfarkt. Omvårdnadsåtgärder var bristfälligt dokumenterade. Studiens omfattning är begränsad vilket gör att resultaten bör beaktas med försiktighet. Konklusion: Fler studier behövs för att undersöka värdet av prehospital behandling med Clopidogrel. / Introduction: Acute myocardial infarction is a very common cause of death. The most important treatment for myocardial infarction is to rapidly open the occluded coronary artery by Perkutan Coronar Intervention (PCI). It is also important that treatment prevents re-occlusion of the coronary artery. This is done by treatment with Clopidogrel which is a blood thrombosis inhibiting and vessel affective medicine. According to a new guideline Clopidogrel should be given already in the ambulance when myocardial infarction is established in order to achieve effect as quickly as possible.Purpose: The purpose of the study was to examine if pre-hospital treatment with Clopidogrel leads to good care in the form of quicker PCI-treatment, reduced length of stay, fewer medical complications, fewer complications related to nursing for patients with STEMI and to examine what kind of nursing care was documented when complications occurred. Method: A retrospective case/control study was carried out where patient journals and database prints from the angiolaboratory internal registry were examined. The study included patients who received PCI-treatment between 1 June 2006 and 1 February 2008 and who arrived with ambulance directly to the angiolaboratory. The case group (n = 37) included patients that received Clopidogrel during ambulance transport and the control group (n = 83) included patients who received Clopidogrel in direct proximity to the PCI-treatment.Results: A difference was found between the groups for the time between arrival at the angio-laboratory and the start of PCI-treatment. The time was extended in the case group (p = 0,05). It is uncertain if pre-hospital treatment with Clopidogrel improves the length of hospital stay, numbers of medical complications and complications related to nursing for STEMI-patients. Nursing treatment was poorly documented. The range of the study is limited, therefore the results should be considered carefully.  Conclusion: Further studies needs to be carried out to examine the value of pre-hospital treatment with Clopidogrel.
3

Effects of antiplatelet agents on platelet and leucocyte function : from laboratory research to clinical practice

Zhao, Lian January 2003 (has links)
No description available.
4

Biochemische Charakterisierung des ADP-Rezeptors P2Y12 und pharmakologische Therapiekontrolle von Thrombozytenfunktionshemmern

Aktas, Barsom. January 2003 (has links) (PDF)
Würzburg, Univ., Diss., 2003.
5

Die konventionelle Plättchenaggregometrie unterschätzt das unzureichende Ansprechen auf Clopidogrel bei KHK-Patienten im Vergleich zu einem P2Y12-spezifischen Test / ADP-induced platelet aggregation frequently fails to detect impaired clopidogrel-responsiveness in patients with coronary artery disease compared to a P2Y12-specific assay

Weinberger, Sarah January 2010 (has links) (PDF)
Die koronare Herzkrankheit ist die häufigste Todesursache in Industrienationen und wird mit Zunahme ihrer Risikofaktoren in Zukunft weiter an Bedeutung gewinnen. Seitdem große Studien zeigen konnten, dass KHK-Patienten von der Behandlung mit dem Thrombozytenaggregationshemmer Clopidogrel profitieren, ist das Thienopyridin Bestandteil der leitliniengerechten Therapie der akuten und chronischen KHK. In den letzten Jahren fanden Forscher jedoch heraus, dass individuelle Unterschiede in der Wirksamkeit von Clopidogrel existieren, die bei Nonrespondern mit einem erhöhten kardiovaskulären Risiko einhergehen. Zur Beurteilung der Relevanz eines verminderten Ansprechens auf Clopidogrel in einem alltäglichen Patientenkollektiv wurde aktuell die Thrombozytenaktivität von 100 konsekutiven Patienten mit stabiler KHK untersucht, die mit mindestens 75 mg Clopidogrel täglich behandelt wurden. Neben dem P2Y12-spezifischen PRI kam dazu auch die Messung der Verschlusszeit im PFA-100®, die ADP-induzierte P-Selektin-Expression und der aktuelle Goldstandard der Thrombozytenaktivitätsmessung, die ADP-induzierte Plättchenaggregometrie, zum Einsatz. Trotz guter Korrelation der Ergebnisse von PRI und Aggregometrie, war die Rate der Nonresponder mit einem PRI > 50% deutlich höher als in der Aggregometrie. Insgesamt fand sich bei 69% der Patienten ein unzureichendes Ansprechen auf Clopidogrel. 39% der Clopidogrel-Nonresponder konnten in der Aggregometrie nicht als solche detektiert werden. In der statistischen Analyse zeigten sich niedrige HDL-Spiegel und eine Hypercholesterinämie in der Vorgeschichte als Einflussfaktoren der Clopidogrel-Nonresponsiveness. Andere kardiovaskuläre Risikofaktoren, Komorbiditäten und Medikamente hatten keine Auswirkung auf die Clopidogrel-Responsiveness. Die Problematik der Clopidogrel-Nonresponsiveness bedarf vor allem wegen der Korrelation mit klinischen Ereignissen und der erhöhten Mortalität einer baldigen Lösung. In Frage kommen dazu der Einsatz neuer Substanzen und eine generelle oder individuelle Dosisanpassung. Unklar ist allerdings noch, welches Konzept am sichersten und ökonomischsten ist. Aktuell ist besonders bei Hochrisikopatienten eine Testung der Clopidogrel-Responsiveness mit individueller Dosisanpassung sinnvoll. Aufgrund der höheren Sensitivität im Vergleich zur Plättchenaggregometrie wäre ein P2Y12-spezifischer Test ähnlich dem PRI dazu am ehesten geeignet. / Incomplete P2Y(12)-inhibition during clopidogrel treatment is associated with increased cardiovascular events and mortality after coronary intervention. We investigated the incidence of impaired individual clopidogrel-responsiveness using a P2Y(12)-specific and pre-treatment-independent assay in a real world situation. One hundred consecutive patients with coronary artery disease (CAD) on combined acetylsalicylic acid and clopidogrel treatment (75 mg/d) and 33 patients on aspirin only were screened for platelet ADP-induced signalling by conventional aggregometry, platelet P-selectin expression and the platelet reactivity index (PRI). Impaired P2Y(12)-specific inhibition by clopidogrel was defined as a PRI>50%. Functional platelet reactivity was significantly lower in clopidogrel-treated patients compared to controls. Impaired individual response to treatment was diagnosed in 69% of clopidogrel-treated patients. Conventional assessment of maximum ADP-induced platelet aggregation failed to detect impaired P2Y(12) inhibition in 36% of patients identified by PRI to have an impaired clopidogrel response. Impaired clopidogrel response was associated with lower HDL levels and a history of hyperlipidaemia. In conclusion, PRI as a P2Y(12)-specific assay to evaluate the treatment effect of clopidogrel in patients with CAD revealed insufficient P2Y(12)-inhibition in two thirds of patients in a real-world scenario indicating a markedly higher incidence than previously assumed. PRI detected significantly more patients with impaired response than conventional platelet aggregation.
6

Biochemische Charakterisierung des ADP-Rezeptors P2Y12 und pharmakologische Therapiekontrolle von Thrombozytenfunktionshemmern / Biochemical characterization of the ADP receptor P2Y12 and pharmacological drug monitoring of anti-platelet compounds

Aktas, Barsom January 2003 (has links) (PDF)
Die Bedeutung der cAMP- und cGMP-abhängigen Proteinkinase für die Hemmung der Plättchenaktivierung und -aggregation ist gut beschrieben. Zahlreiche fundamentale Plättchenantworten wie die Erhöhung der intrazellulären Calciumkonzentration, die Exposition von Adhäsionsrezeptoren und die Aktinpolymerisation können durch die Cyclonukleotid vermittelte Kinasenaktivierung fast vollständig gehemmt werden. Die Vielfalt der cGMP bindenden Proteine und deren synergistische Interaktion mit cAMP vermittelten Signalwegen deuten auf eine Reihe von cGMP Zielproteinen hin. Vor kurzem wurde die zentrale Bedeutung einer Gi-Protein Stimulation für die Plättchenaktivierung und –aggregation gezeigt. In dieser Dissertation wurde daher der Frage nachgegangen, ob Signalmoleküle, die an Gi-Protein vermittelten Effekten beteiligt sind, einen Angriffspunkt für cAMP/cGMP-abhängige Proteinkinasen darstellen. Zu diesem Zweck wurden die Effekte erhöhter cGMP Spiegel und die selektive Aktivierung der cGMP-abhängigen Proteinkinase auf die adrenerge und purinerge Rezeptor vermittelte Erniedrigung stimulierter cAMP Konzentrationen untersucht. In unseren Versuchen konnte erstmalig gezeigt werden, dass eine Erhöhung der intrazellulären cGMP Konzentration Gi-Protein vermittelte Signale hemmt. Dieses erfolgt nicht auf Grund einer cGMP stimulierten Aktivierung von cyclonukleotidabbauenden Phosphodiesterasen, sondern auf Grund einer Aktivierung der cGMP-abhängigen Proteinkinase. In Anbetracht der essentiellen Bedeutung der Gi-Protein Stimulation für die Plättchenaktivierung stellt dies einen wichtigen Mechanismus dar, wie das aus dem Endothel freigesetzte NO über cGMP die Thrombozytenfunktion hemmt. Klinisch bedeutsame Substanzen wie Clopidogrel oder Ticlopidin imitieren diesen in vivo Effekt des NO, indem sie extrazellulär über eine Rezeptorhemmung Gi-Protein Stimulation verhindern. (Aktas et al., Biochem Pharmacol 2002; 64: 433-439) Dipyridamol und im Besonderen die Kombination von Dipyridamol und niedrig dosierter Acetylsalicylsäure sind in der Sekundärprävention des Schlaganfalles sehr gut wirksam. Jedoch sind die hierfür zu Grunde liegenden biochemischen Mechanismen noch nicht vollständig aufgeklärt. Da für das Dipyridamol eine in vitro Hemmung der cGMP-spezifischen Phosphodiesterase 5 (PDE 5) nachgewiesen ist, wurde in dieser Arbeit untersucht, ob Dipyridamol in therapeutisch relevanten Konzentrationen die NO/cGMP vermittelte Effekte auf die Plättchenfunktion unter ex vivo Bedingungen verstärkt. Die Phosphorylierung von VASP (VAsodilator-Stimulated Phosphoprotein) diente dabei als Meßparameter NO/cGMP Signale in Thrombozyten mit Hilfe von Antikörpern und Western Blot Technik zu quantifizieren. Die Sekretion von Serotonin aus Thrombozyten und die Aktivität der Thromboxansynthase wurden durch die fluorimetrische Bestimmung derivatisierten Serotonins bzw. des Synthaseprodukts Malondialdehyd quantifiziert. Endotheliale Faktoren wie NO oder PG-I2 erhöhen cGMP bzw. cAMP, die zu einer Plättchenhemmung und gleichzeitigen VASP Phosphorylierung führen. In in vitro Versuchen potenzierte Dipyridamol in einer therapeutisch relevanten Konzentration (3,5 µmol/l) nur die cGMP vermittelte, aber nicht die cAMP vermittelte VASP Phosphorylierung. Darüber hinaus konnte Dipyridamol (3,5 µmol/l) die Hemmung von Plättchenfunktionen wie der Serotoninsekretion und die Aktivität der Thromboxansynthase durch einen NO Donor klar verstärken. Schließlich steigerte Dipyridamol die NO vermittelte VASP Phosphorylierung auch in Thrombozyten von Probanden, die vorher Dipyridamol eingenommen hatten. Unter therapeutisch relevanten Bedingungen verstärkt also Dipyridamol NO/cGMP Signalwege und damit die Hemmung von Thrombozyten. Dieser Befund bekräftigt die Vorstellung, dass die Verstärkung endothelialer NO/cGMP Effekte auf Thrombozyten eine wichtige Komponente der Dipyridamol Wirkung unter in vivo Bedingungen darstellt. (Aktas et al., Stroke 2003; 34(3): 764-769) Die Stimulation von Thrombozyten führt u.a. zu einer Sekretion von Plättchenaktivatoren wie Thrombin, Thromboxan A2, ADP oder Serotonin aus dem Zellinnern. Durch diesen Prozess der Degranulierung können nun weitere Thrombozyten aktiviert werden. Die Sekretion stellt somit einen wichtigen, verstärkenden Schritt in der Aktivierung von Thrombozyten während der Hämostase dar. Diese Arbeit zeigt, dass in Thrombozyten eine Gi-Protein Aktivierung nicht nur wie bisher angenommen eine initiale Sekretion durch Gq verstärkt und aufrecht erhält, sondern der eigentliche Stimulus ist, der die Degranulierung von Thrombozyten auslöst. Die Stimulation Gq vermittelter Signalwege ist nur insofern erforderlich, als diese das Auslösen der Sekretion durch eine Aktivierung von Gi-Proteinen ermöglichen. Die Stimulierung beider G-Proteine ist daher essentiell für die thrombozytäre Sekretion. Zudem konnte die Phospholipase D als ein neuer Effektor des P2Y12 nachgewiesen werden, deren Stimulierung wahrscheinlich zur Degranulierung von Thrombozyten führt. Dieser Mechanismus könnte der Entscheidende sein, der der essentiellen Rolle des Gi-Proteins bei der Stimulation der Sekretion und der Aktivierung von Thrombozyten zu Grunde liegt und könnte ein neues Licht auf die Wirkweise des Clopidogrels und des Ticlopidins werfen, die irreversibel an den P2Y12 Rezeptor binden. (Aktas et al., Manuskript in Vorbereitung) / The important role of cGMP and cGMP-dependent protein kinase for the inhibition of platelet activation and aggregation is well established and due to the inhibition of fundamental platelet responses such as agonist-stimulated calcium increase, exposure of adhesion receptors and actin polymerization. The diversity of cGMP binding proteins and their synergistic interaction with cAMP signaling in inhibiting platelets indicates that a variety of cGMP targets contribute to its anti-platelet action. Since stimulation of Gi-proteins was recently shown to be essential for complete platelet activation/aggregation, the possibility that Gi-signaling events are cGMP/cGMP-dependent protein kinase targets was investigated. Thus, the effect of elevated cGMP levels and selective cGMP-dependent protein kinase activation on purinergic and adrenergic receptor-evoked decrease of platelet cAMP content was closely examined. Experiments with a selective activator of cGMP-dependent protein kinase demonstrate for the first time a cGMP-caused Gi-protein inhibition. Our data suggest that this effect is mediated by cGMP-dependent protein kinase. Considering the essential role of Gi-signaling for platelet activation, we propose that inhibition of Gi-mediated signaling by cGMP/cGMP-dependent protein kinase is an important mechanism of action contributing to platelet inhibition by cGMP-elevating endothelium derived factors and drugs. (Aktas et al., Biochem Pharmacol 2002; 64: 433-439) Dipyridamole and in particular dipyridamole in combination with low dose aspirin are very effective in preventing recurrent stroke. However, the mechanism(s) underlying this dipyridamole effect have not been elucidated. Since dipyridamole inhibits the cGMP-specific phosphodiesterase type V in vitro, we hypothesized and tested whether therapeutically relevant dipyridamole concentrations enhance NO/cGMP-mediated effects in intact human platelets studies ex vivo. Phosphorylation of VASP (VAsodilator-Stimulated Phosphoprotein), an established marker of NO/cGMP effects in human platelets, was quantified by phosphorylation-specific antibodies and western blots. Serotonin secretion and thromboxane synthase activity were determined by fluorimetric quantification of derivatized serotonin and synthase product, respectively. Endothelium-derived factors such as NO and PG-I2 are known to elevate both, cGMP and cAMP levels with concomitant platelet inhibition and VASP phosphorylation. In our in vitro experiments, therapeutically relevant dipyridamole concentrations (3.5 µmol/l) only amplified cGMP-mediated VASP phosphorylation due to NO donor sodium nitroprusside, but not cAMP-mediated effects. Furthermore, thromboxane synthase activity and serotonin secretion, events important for initial platelet activation, were inhibited by sodium nitroprusside, an effect also enhanced by dipyridamole demonstrating the functional relevance of these observations. Finally, the ex vivo enhancement of NO/cGMP effects was also observed with platelets obtained from healthy volunteers treated with extended released dipyridamole. Under therapeutically relevant dipyridamole conditions, dipyridamole enhances platelet inhibition by amplifying the signalling of the NO-donor SNP. These data support the concept that enhancement of endothelium-derived NO/cGMP-mediated signalling in vivo is an important component of dipyridamole action. (Aktas et al., Stroke 2003; 34(3): 764-769) Activation of platelets causes secretion of several platelet activators, including thrombin, thromboxan A2, ADP or serotonin. By this process, other platelets get attracted and contribute to the thrombus. Therefore, secretion represents an important amplifying mechanism during platelet activation and hemostasis. In the present work, we could demonstrate that Gi-protein signalling does not only amplify initial secretion induced by Gq-protein activation, as it has been proposed so far, but is the actual stimulus to induce secretion. However, stimulation of Gq-proteins is required, since this enables Gi-proteins to induce secretion. Therefore, activation of both G-proteins is essential for platelet release. We could exclude inhibition of adenylyl cyclase to be the major mechanism contributing to the observed effects of Gi-proteins during secretion. We suggest phospholipase D as a novel effector of the Gi-coupled ADP receptor P2Y12, whose stimulation may lead to degranulation of platelets. This mechanism could be the major one underlying the essential role of Gi-proteins during secretion and activation of platelets. This could provide new insights in the mechanism by which P2Y12 receptor antagonists like clopidogrel exert their antithrombotic action. (Aktas et al., manuscript in preparation)
7

Utveckling och validering av en LC-MS/MS metod för kvantifiering av clopidogrel och dess metabolit i plasma

Shamon, Doreen-Marie January 2010 (has links)
<p>Clopidogrel is an antiplatelet substance that prevents blood coagulation in the arteries. It is an inactive pro drug that becomes activated after first-pass metabolism by the liver. The active metabolite of clopidogrel is 2-oxoclopidogrel, which is unstable therefore pharmacokinetic data is obtained by measuring the inactive metabolite clopidogrel acid in plasma. Clopidogrel is taken orally in tablet form. The aim of this project was to develop a LC-MS/MS method for quantification of clopidogrel and its metabolite in plasma.</p><p> </p><p>The method has been developed by optimizing the sample preparation. Different extraction procedures and extraction columns were tested, for example, by changing the extraction column from a C8 silica sorbent to Oasis HLB (a polymer sorbent). Different internal standards were evaluated as a result of discovering the signal suppression of the previous internal standard clopidogrel acid.  Flupentixol was found to be the best candidate.</p>
8

Interaction between proton pump inhibitors and clopidogrel

Oyetayo, Olaonipekun Oladoyin 03 January 2011 (has links)
Introduction: Proton pump inhibitors (PPI) may impair the biotransformation of clopidogrel leading to increased major adverse cardiac events (MACE). Available studies have focused solely on patients receiving clopidogrel following a cardiac event. Given the widespread use of this combination, (about 64% in a recent study), this represents a major interaction that deserves further study. The objective of this thesis was to determine if the potential interaction between PPIs and clopidogrel leads to an increase in MACE in high-risk atherosclerotic patients receiving clopidogrel and PPIs as compared to clopidogrel alone. Methods: We conducted a retrospective chart review of patients in the University Hospital System who received clopidogrel between January 1, 2007 and April 30, 2009. Patients were included if they were hospitalized for acute coronary syndromes, stroke/TIA, revascularization (coronary, cerebral or peripheral arteries), or aspirin allergy. The primary outcome was the composite of myocardial infarction (MI), stroke/transient ischemic attack (TIA), coronary artery revascularization, or death (all cause) during the first year following discharge. Secondary outcomes included the composite of MI, stroke /TIA, revascularization (coronary, cerebral or peripheral arteries), or death. Bivariate analyses were conducted using Student’s t test, Mann Whitney U and Chi-square tests where appropriate. Multivariate analysis was conducted to adjust for baseline differences. Results: Overall, 1700 charts were reviewed and 572 patients met study criteria. The median follow-up was 332 days. The most common indication for clopidogrel use was coronary artery revascularization (66%). There were 201 patients in the clopidogrel with PPI group and 371 patients in the clopidogrel without PPI group. Baseline characteristics were evenly matched between both groups except for smoking, liver disease, and prior receipt of a PPI. The primary endpoint occurred in 21 patients in the clopidogrel with PPI group and 38 patients in the clopidogrel without PPI group (10% vs. 10%, p = 0.9, OR 1.02, 95% CI 0.58 – 1.80). The primary endpoint was unchanged after multivariate adjustments for baseline differences (adjusted OR 0.98, 95% CI 0.54 – 1.75). Likewise, there was no difference in the secondary endpoint (14% vs. 15%, p = 0.8, OR 1.02; 95% CI 0.58 – 1.80). The secondary endpoint was also unchanged after multivariate adjustments for baseline differences (adjusted OR 1.04, 95% CI (0.61 – 1.75) Conclusion: Patients receiving clopidogrel with a PPI demonstrated similar rates of MACE when compared to patients receiving clopidogrel without a PPI. / text
9

Auswirkungen von Acetylsalicylsäure und Clopidogrel auf das Kollateralgefässwachstum im zerebralen Arteriogenesemodell der Ratte /

Dülsner, André January 2009 (has links)
Zugl.: Berlin, Freie Universiẗat, Diss., 2009.
10

Estudio de la biodisponibilidad relativa de clopidogrel (Expansia®), formulación oral de Laboratorio Stein S. A. versus la formulación de referencia del mercado, Plavix® — Study of the relative bioavailability of clopidogrel (ExpansiaTM) oral formulation of Stein Laboratory S. A. versus market reference, PlavixTM / Study of the relative bioavailability of clopidogrel (ExpansiaTM) oral formulation of Stein Laboratory S. A. versus market reference, PlavixTM

Toledo Parada, Pablo Antonio January 2011 (has links)
Memoria para optar al título de Químico Farmacéutico

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