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Argatroban
Argatroban is an anticoagulant that is a small molecule direct thrombin inhibitor. In 2000, argatroban was licensed by the Food and Drug Administration (FDA) for prophylaxis or treatment of thrombosis in patients with heparin-induced thrombocytopenia (HIT). In 2002, it was approved for use during percutaneous coronary interventions in patients who have HIT or are at risk for developing it. In 2012, it was approved by the MHRA in the UK for anticoagulation in patients with heparin-induced thrombocytopenia Type II (HIT) who require parenteral antithrombotic therapy. Argatroban is given intravenously and drug plasma concentrations reach steady state in 1–3 hours. Argatroban is metabolized in the liver and has a half-life of about 50 minutes. It is monitored by PTT. Because of its hepatic metabolism, it may be used in patients with renal dysfunction. (This is in contrast to lepirudin, a direct thrombin inhibitor that is primarily renally cleared). Transitioning to warfarin in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heparin-induced Thrombocytopenia
Heparin-induced thrombocytopenia (HIT) is the development of thrombocytopenia (a low platelet count), due to the administration of various forms of heparin, an anticoagulant. HIT predisposes to thrombosis (the abnormal formation of blood clots inside a blood vessel) because platelets release microparticles that activate thrombin, thereby leading to thrombosis. When thrombosis is identified the condition is called heparin-induced thrombocytopenia and thrombosis (HITT). HIT is caused by the formation of abnormal antibodies that activate platelets. If someone receiving heparin develops new or worsening thrombosis, or if the platelet count falls, HIT can be confirmed with specific blood tests. The treatment of HIT requires stopping heparin treatment, and both protection from thrombosis and choice of an agent that will not reduce the platelet count any further. Several alternatives are available for this purpose; mainly used are danaparoid, fondaparinux, argatroban, and bivalirudin. W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepirudin
Lepirudin is an anticoagulant that functions as a direct thrombin inhibitor. Brand name: Refludan, Generic: Lepirudin rDNA for injection. Lepirudin is a recombinant hirudin derived from yeast cells. Lepirudin is almost identical to hirudin extracted from ''Hirudo medicinalis'', having the amino acid sequence LTYTDCTESGQNLCLCEGSNVCGQGNKCILGSDGEKNQCVTGEGTPKPQSHNDGDFEEIPEEYLQ with disulfide bridges at Cys6-Cys14, Cys16-Cys28 and Cys22-Cys39, and differs from by the substitution of leucine for isoleucine at the N-terminal end of the molecule and the absence of a sulfate group on the tyrosine at position 63. Lepirudin may be used as an anticoagulant when heparins (unfractionated or low-molecular-weight) are contraindicated because of heparin-induced thrombocytopenia Heparin-induced thrombocytopenia (HIT) is the development of thrombocytopenia (a low platelet count), due to the administration of various forms of heparin, an anticoagulant. HIT predisposes to thrombosis (the abnorma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anticoagulant
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where they help keep the bite area unclotted long enough for the animal to obtain some blood. As a class of medications, anticoagulants are used in therapy for thrombotic disorders. Oral anticoagulants (OACs) are taken by many people in pill or tablet form, and various intravenous anticoagulant dosage forms are used in hospitals. Some anticoagulants are used in medical equipment, such as sample tubes, blood transfusion bags, heart–lung machines, and dialysis equipment. One of the first anticoagulants, warfarin, was initially approved as a rodenticide. Anticoagulants are closely related to antiplatelet drugs and thrombolytic drugs by manipulating the various pathways of blood coagulation. Specifically, antiplatelet drugs inhibit platelet agg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravenous
Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrients for those who cannot, or will not—due to reduced mental states or otherwise—consume food or water by mouth. It may also be used to administer medications or other medical therapy such as blood products or electrolytes to correct electrolyte imbalances. Attempts at providing intravenous therapy have been recorded as early as the 1400s, but the practice did not become widespread until the 1900s after the development of techniques for safe, effective use. The intravenous route is the fastest way to deliver medications and fluid replacement throughout the body as they are introduced directly into the circulatory system and thus quickly distributed. For this reason, the intravenous route of administration is also used for the consumpti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Direct Thrombin Inhibitors
Direct thrombin inhibitors (DTIs) are a class of medication that act as anticoagulants (delaying blood clotting) by directly inhibiting the enzyme thrombin (factor IIa). Some are in clinical use, while others are undergoing clinical development. Several members of the class are expected to replace heparin (and derivatives) and warfarin in various clinical scenarios. Types There are three types of DTIs, dependent on their interaction with the thrombin molecule. ''Bivalent'' DTIs (hirudin and analogs) bind both to the active site and exosite 1, while univalent DTIs bind only to the active site. The third class of inhibitors, which are gaining importance recently, is the allosteric inhibitors. Bivalent Hirudin and derivatives were originally discovered in ''Hirudo medicinalis'': * Hirudin * Bivalirudin (transient inhibition - is cleaved by thrombin) * Lepirudin * Desirudin Univalent Univalent DTIs include: * Argatroban * Inogatran * Melagatran (and its prodrug ximelagatran) * Dabiga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Normalized Ratio
The prothrombin time (PT) – along with its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) – is an assay for evaluating the ''extrinsic'' pathway and common pathway of coagulation. This blood test is also called ''protime INR'' and ''PT/INR''. They are used to determine the clotting tendency of blood, in such things as the measure of warfarin dosage, liver damage, and vitamin K status. PT measures the following coagulation factors: I (fibrinogen), II (prothrombin), V (proaccelerin), VII (proconvertin), and X (Stuart–Prower factor). PT is often used in conjunction with the activated partial thromboplastin time (aPTT) which measures the ''intrinsic'' pathway and common pathway of coagulation. Laboratory measurement The reference range for prothrombin time depends on the analytical method used, but is usually around 12–13 seconds (results should always be interpreted using the reference range from the laboratory that performed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prothrombin Time
The prothrombin time (PT) – along with its derived measures of prothrombin ratio (PR) and international normalized ratio (INR) – is an assay for evaluating the ''extrinsic'' pathway and common pathway of coagulation. This blood test is also called ''protime INR'' and ''PT/INR''. They are used to determine the clotting tendency of blood, in such things as the measure of warfarin dosage, liver damage, and vitamin K status. PT measures the following coagulation factors: I (fibrinogen), II (prothrombin), V (proaccelerin), VII (proconvertin), and X (Stuart–Prower factor). PT is often used in conjunction with the activated partial thromboplastin time (aPTT) which measures the ''intrinsic'' pathway and common pathway of coagulation. Laboratory measurement The reference range for prothrombin time depends on the analytical method used, but is usually around 12–13 seconds (results should always be interpreted using the reference range from the laboratory that performed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warfarin
Warfarin, sold under the brand name Coumadin among others, is a medication that is used as an anticoagulant (blood thinner). It is commonly used to prevent blood clots such as deep vein thrombosis and pulmonary embolism, and to prevent stroke in people who have atrial fibrillation, valvular heart disease, or artificial heart valves. Less commonly, it is used following ST-segment elevation myocardial infarction and orthopedic surgery. It is generally taken by mouth, but may also be used intravenously. The common side effect is bleeding. Less common side effects may include areas of tissue damage and purple toes syndrome. Use is not recommended during pregnancy. The effects of warfarin typically should be monitored by checking prothrombin time (INR) every one to four weeks. Many other medications and dietary factors can interact with warfarin, either increasing or decreasing its effectiveness. The effects of warfarin may be reversed with phytomenadione (vitamin K1), fresh f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Thromboplastin Time
The partial thromboplastin time (PTT), also known as the activated partial thromboplastin time (aPTT or APTT), is a blood test that characterizes coagulation of the blood. A historical name for this measure is the kaolin-cephalin clotting time (KCCT), reflecting kaolinite, kaolin and phosphatidylethanolamine, cephalin as materials historically used in the test. Apart from detecting abnormalities in blood clotting, partial thromboplastin time is also used to monitor the treatment effect of heparin, a widely prescribed Anticoagulant, drug that reduces blood's tendency to clot. The PTT measures the overall speed at which blood clots form by means of two consecutive series of biochemical reactions known as the Coagulation#Intrinsic pathway, ''intrinsic'' pathway and Coagulation#Common pathway, common pathway of coagulation. The PTT indirectly measures action of the following coagulation factors: fibrinogen, I (fibrinogen), thrombin, II (prothrombin), Factor V, V (proaccelerin), Facto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver
The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it is located in the quadrant (anatomy), right upper quadrant of the abdomen, below the thoracic diaphragm, diaphragm. Its other roles in metabolism include the regulation of Glycogen, glycogen storage, decomposition of red blood cells, and the production of hormones. The liver is an accessory digestive organ that produces bile, an alkaline fluid containing cholesterol and bile acids, which helps the fatty acid degradation, breakdown of fat. The gallbladder, a small pouch that sits just under the liver, stores bile produced by the liver which is later moved to the small intestine to complete digestion. The liver's highly specialized biological tissue, tissue, consisting mostly of hepatocytes, regulates a w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive. The term is also used more generally to characterize any type of exponential (or, rarely, non-exponential) decay. For example, the medical sciences refer to the biological half-life of drugs and other chemicals in the human body. The converse of half-life (in exponential growth) is doubling time. The original term, ''half-life period'', dating to Ernest Rutherford's discovery of the principle in 1907, was shortened to ''half-life'' in the early 1950s. Rutherford applied the principle of a radioactive element's half-life in studies of age determination of rocks by measuring the decay period of radium to lead-206. Half-life is constant over the lifetime of an exponentially decaying quantity, and it is a characteristic unit for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angioplasty
Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. A deflated balloon attached to a catheter (a balloon catheter) is passed over a guide-wire into the narrowed vessel and then inflated to a fixed size. The balloon forces expansion of the blood vessel and the surrounding muscular wall, allowing an improved blood flow. A stent may be inserted at the time of ballooning to ensure the vessel remains open, and the balloon is then deflated and withdrawn. Angioplasty has come to include all manner of vascular interventions that are typically performed percutaneously. The word is composed of the combining forms of the Greek words ἀνγεῖον ' "vessel" or "cavity" (of the human body) and πλάσσω ' "form" or "mould". Uses and indications Coronary angioplasty A coronary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
