Antithrombotic agents effects

Fondaparinux, the factor Xa-binding pentasaccharide (Arixtra, MW 1,728 Da), is prepared synthetically, unlike UFH, LMWH and danaparoid, which are obtained from animal sources. Despite only inactivating free factor Xa, clinical trials indicate that fondaparinux is an effective antithrombotic agent, both for venous thromboembolism prophylaxis and treatment, as well as for acute coronary syndrome and ST elevation myocardial infarction [4]. 

Aspirin is maximally effective as an antithrombotic agent at the comparatively low dose of 81 to 325 mg per day. (The antipyretic dose of aspirin in adults is 325 to 650 mg every 4 h.) Higher doses of aspirin are actually contraindicated in patients prone to thromboembolism. At higher doses, aspirin also reduces synthesis of prostacyclin, another arachidonic acid metabolite. Prostacyclin normally inhibits platelet aggregation. The prophylactic administration of low-dose aspirin has been shown to increase survival following myocardial infarction, decrease incidence of stroke, and assist in maintenance of patency of coronary bypass grafts. 

Atarashi H, Endoh Y, Saitoh H, Kiashida H, Hayakawa H. Chronotropic effects of cilostazol, a new antithrombotic agent, in patients with bradyarrhythmias. J Car-diovasc Pharmacol 1998 31 534-9. 

Acetaminophen is similar to salicylates in that it is a useful analgesic for mild to moderate pain, with equal efficacy to aspirin, and like aspirin, it is antipyretic. However, acetaminophen exerts little if any effects on platelet aggregation and is not antiinflammatory. Thus, it is not useful for patients with arthritis or other inflammatory diseases. It is also not useful as an antithrombotic agent in the prevention of myocardial infarction or transient ischemic attacks. Acetaminophen does not produce the gastric ulceration that can occur with aspirin and is useful in patients who are salicylate sensitive or who have a history of ulcers or other gastric ulcerations. 

Mechanism of Action An antiplatelet and antithrombotic agent that binds to platelet receptorglycoproteinllb/Illa, preventing binding of fibrinogen. Therapeutic Effect inhibits platelet aggregation and thrombus formation. 

Garlic is used for a variety of reasons, and some of the attributes associated with it, e.g. for cancer prevention, or to reduce heart attacks, may not be substantiated. Other properties such as antimicrobial activity, effects on lipid metabolism, and platelet aggregation inhibitory action have been demonstrated. Ajoene has been shown to be a potent antithrombotic agent through inhibition of platelet aggregation. 

Several potent inhibitors of fibrinogen binding to gpIIb/IIIa are now known, and some have proven to be effective antithrombotic agents. These inhibitors tend either to be small cyclic peptide mimetics, in which the conformation of an RGD sequence is constrained by macrocyclization, or they are non-peptidic molecules containing functional group mimetics of the Arg and Asp side chains, held in the correct geometry for interaction with the receptor. Examples of both classes are shown in... 

CONTENTS Preface. Bruce E. Maryanoff and Cynthia A. Maryanoft. Novel An-tipsychotics with Unique D /5-HT1A Affinity and Minimal Extrapyramidal Side Effect Liability. Allen B. Reitz and Malcolm K. Scott. Antiplatelet and Antithrombotic Agents From Viper Venom Proteins, to Peptides and Peptidomimetics. to Small Organic Molecules, Peter L. Barker and Robert R. Webb. II. Discovery and Preclinical Development of the Serotonin Reuptake Inhibitor Sertraline, Willard M. Welch. Boronic Acid Inhibitors of Dipeptidyipeptidase IV A New Class of Immunosuppressive Agents, Roger J. Snow. Index. 

De ite differmces in their mechanisms of action and in vitro activities, pentasaccharide, DX-9065a and TAP have been shown to be effective antithrombotic agents in experimental models of venous thrombosis, coronary artery occlusion, arterial thrombolysis and acute reocclusion, restenosis after angioplasty, dialysis, and DIG. Pentasaccharide has also demonstrated measurable antithrombotic effects in human trials. Both TAP and DX-9065a produce measurable in vitro anticoagulant effects. In contrast, pentasaccharide does not produce an anticoagulant effect by the typical clot based assays. Thus, with fector Xa inhibitors there is not necessarily a correlation between current lab assays and antithrombotic efficacy as there is with heparin. 

The cyclo-oxygenase metabolite prostacyclin is a potent, short-lived vasodilator and antithrombotic agent. Intravenous administration of the commercially available form of prostacyclin, epoprostenol, relieves the symptoms of primary pulmonary hypertension by dilating the pulmonary vasculature [99]. A stable prostacyclin analogue, iloprost, appears to be similarly effective when administered as an aerosol and obviates the logistical problems associated with maintained intravenous administration [100]. 

Photochemically induced thrombosis [47] light activated photosensitiser causing endothelial injury. Platelet rich, but significant fibrin/ red cell content Coronary artery blood flow Efficacy of antithrombotic agents adjunctive agents in thrombolysis effects on restenosis... 

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