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Echothiophate Synthesis
Echothiophate (Phospholine) is an irreversible acetylcholinesterase inhibitor. Uses It is used as an ocular antihypertensive in the treatment of open angle glaucoma and, in some cases, accommodative esotropia. It is available under several trade names such as Phospholine Iodide ( Wyeth-Ayerst). Echothiophate binds irreversibly to cholinesterase. Because of the very slow rate at which echothiophate is hydrolyzed by cholinesterase, its effects can last a week or more. Adverse effects include muscle spasm and other systemic effects. Mechanism of action It covalently binds by its phosphate group to serine group at the active site of the cholinesterase. Once bound, the enzyme is permanently inactive and the cell has to make new enzymes. Shortage Wyeth Pharmaceuticals stopped manufacturing echothiophate iodide in the US in 2003. After contacting the American Academy of Ophthalmology (AAO), Wyeth rescinded their decision and, according to AAO public relations representative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Drop
Eye drops or eyedrops are liquid drops applied directly to the surface of the eye usually in small amounts such as a single drop or a few drops. Eye drops usually contain saline to match the salinity of the eye. Drops containing only saline and sometimes a lubricant are often used as artificial tears to treat dry eyes or simple eye irritation such as itching or redness. Eye drops may also contain one or more medications to treat a wide variety of eye diseases. Depending on the condition being treated, they may contain steroids, antihistamines, sympathomimetics, beta receptor blockers, parasympathomimetics, parasympatholytics, prostaglandins, nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, antifungals, or topical anesthetics. Eye drops have less of a risk of side effects than do oral medicines, and such risk can be minimized by occluding the lacrimal punctum (i.e. pressing on the inner corner of the eye) for a short while after instilling drops. Prior t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholinesterase Inhibitor
Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level and duration of action of acetylcholine in the central nervous system, autonomic ganglia and neuromuscular junctions, which are rich in acetylcholine receptors. Acetylcholinesterase inhibitors are one of two types of cholinesterase inhibitors; the other being butyryl-cholinesterase inhibitors. Acetylcholinesterase is the primary member of the cholinesterase enzyme family. Acetylcholinesterase inhibitors are classified as reversible, irreversible, or quasi-irreversible (also called pseudo-irreversible). Mechanism of action Organophosphates Organophosphates like tetraethyl pyrophosphate (TEPP) and sarin inhibit cholinesterases, enzymes that hydrolyze the neurotransmitter acetylcholine. The active centre of cholinesterases feature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocular Antihypertensive
Ocular hypertension is the presence of elevated fluid pressure inside the eye (intraocular pressure), usually with no optic nerve damage or visual field loss. For most individuals, the normal range of intraocular pressure is between 10 mmHg and 21 mmHg. It is estimated that approximately 2-3% of people aged 52-89 years old have ocular hypertension of 25 mmHg and higher, and 3.5% of people 49 years and older have ocular hypertension of 21 mmHg and higher. Elevated intraocular pressure is an important risk factor and symptom of glaucoma. Accordingly, most individuals with consistently elevated intraocular pressures of greater than 21mmHg, particularly if they have other risk factors, are treated in an effort to prevent vision loss from glaucoma. Pathophysiology One of the fluids inside the eye is called aqueous humor, and it contains 99% water and removes waste. Aqueous humor is transparent and thin, located in the anterior chamber, which is the area between the cornea and iris. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucoma
Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of sight" because the loss of vision usually occurs slowly over a long period of time. A major risk factor for glaucoma is increased pressure within the eye, known as Intraocular pressure, intraocular pressure (IOP). It is associated with old age, a family history of glaucoma, and certain medical conditions or the use of some medications. The word ''glaucoma'' comes from the Ancient Greek word (), meaning 'gleaming, blue-green, gray'. Of the different types of glaucoma, the most common are called open-angle glaucoma and closed-angle glaucoma. Inside the eye, a liquid called Aqueous humour, aqueous humor helps to maintain shape and provides nutrients. The aqueous humor normally drains through the trabecular meshwork. In open-angle glaucoma, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esotropia
Esotropia () is a form of strabismus in which one or both eyes turn inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance. It is the opposite of exotropia and usually involves more severe axis deviation than esophoria. Esotropia is sometimes erroneously called "lazy eye", which describes the condition of amblyopia; a reduction in vision of one or both eyes that is not the result of any pathology of the eye and cannot be resolved by the use of corrective lenses. Amblyopia can, however, arise as a result of esotropia occurring in childhood: In order to relieve symptoms of diplopia or double vision, the child's brain will ignore or "suppress" the image from the esotropic eye, which when allowed to continue untreated will lead to the development of amblyopia. Treatment options for esotropia include glasses to correct refractive errors (see accommodative esotropia below), the use of Prism (optics), pris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wyeth-Ayerst
Wyeth Pharmaceuticals Inc. was a pharmaceutical company until it was purchased by Pfizer in 2009. The company was founded in Philadelphia, Pennsylvania, in 1860 as John Wyeth and Brother. Its headquarters moved to Collegeville, Pennsylvania, and Madison, New Jersey, before its headquarters were consolidated with Pfizer's in New York City after the 2009 merger. Wyeth manufactured over-the-counter (OTC) drugs Robitussin and the analgesic Advil (ibuprofen) as well as prescription drugs Premarin and Effexor. History 1860–1899 In 1860, pharmacists John (1834–1907) and Frank Wyeth opened a drugstore with a small research lab on Walnut Street in Philadelphia. In 1862, on the suggestion of doctors, they began to manufacture large quantities of commonly ordered medicines. They were successful, and in 1864 they began supplying medicines and beef extract to the Union army during the Civil War. In 1872, Henry Bower, an employee of Wyeth, developed one of the first rotary c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cholinesterase
The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters: : an acylcholine + H2O = choline + a carboxylate Several of these serve as neurotransmitters. Thus, it is either of two enzymes that catalyze the hydrolysis of these cholinergic neurotransmitters, such as breaking acetylcholine into choline and acetic acid. These reactions are necessary to allow a cholinergic neuron to return to its resting state after activation. For example, in muscle contraction, acetylcholine at a neuromuscular junction triggers a contraction; but for the muscle to relax afterward, rather than remaining locked in a tense state, the acetylcholine must be broken down by a choline esterase. The main type for that purpose is acetylcholinesterase (also called choline esterase I or erythrocyte cholinesterase); it is found mainly in chemical synapses and red blood cell membranes. The other type is butyrylcholin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adverse Drug Reaction
An adverse drug reaction (ADR) is a harmful, unintended result caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or may result from the combination of two or more drugs. The meaning of this term differs from the term "side effect" because side effects can be beneficial as well as detrimental. The study of ADRs is the concern of the field known as ''pharmacovigilance''. An adverse event (AE) refers to any unexpected and inappropriate occurrence at the time a drug is used, whether or not the event is associated with the administration of the drug. An ADR is a special type of AE in which a causative relationship can be shown. ADRs are only one type of medication-related harm. Another type of medication-related harm type includes not taking prescribed medications, known as non-adherence. Non-adherence to medications can lead to death and other negative outcomes. Adverse drug reactions require the use of a medication. Classific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Spasm
A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscle cramp which is accompanied by a sudden burst of pain. A muscle cramp is usually harmless and ceases after a few minutes. It is typically caused by ion imbalance or muscle fatigue. There are other causes of involuntary muscle contractions, and some of these may cause a health problem. A series of spasms, or permanent spasms, is referred to as a "spasmism". Description and causes Spasms occur when the part of the brain that controls movement malfunctions, causing involuntary muscle activity. A spasm may be a muscle contraction caused by abnormal nerve stimulation or by abnormal activity of the muscle itself. Causes The cause of spasms is often unknown, but it can be due to an inherited genetic problem, a side effect of medicatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Effect
An adverse drug reaction (ADR) is a harmful, unintended result caused by taking medication. ADRs may occur following a single dose or prolonged administration of a drug or may result from the combination of two or more drugs. The meaning of this term differs from the term "side effect" because side effects can be beneficial as well as detrimental. The study of ADRs is the concern of the field known as ''pharmacovigilance''. An adverse event (AE) refers to any unexpected and inappropriate occurrence at the time a drug is used, whether or not the event is associated with the administration of the drug. An ADR is a special type of AE in which a causative relationship can be shown. ADRs are only one type of medication-related harm. Another type of medication-related harm type includes not taking prescribed medications, known as non-adherence. Non-adherence to medications can lead to death and other negative outcomes. Adverse drug reactions require the use of a medication. Classific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methyl Iodide
Iodomethane, also called methyl iodide, and commonly abbreviated "MeI", is the chemical compound with the formula CH3I. It is a dense, colorless, volatile liquid. In terms of chemical structure, it is related to methane by replacement of one hydrogen atom by an atom of iodine. It is naturally emitted in small amounts by rice plantations. It is also produced in vast quantities estimated to be greater than 214,000 tons annually by algae and kelp in the world's temperate oceans, and in lesser amounts on land by terrestrial fungi and bacteria. It is used in organic synthesis as a source of methyl groups. Preparation and handling Iodomethane is formed via the exothermic reaction that occurs when iodine is added to a mixture of methanol with red phosphorus. The iodinating reagent is phosphorus triiodide that is formed ''in situ:'' :3 CH3OH + PI3 → 3 CH3I + H2PO3H Alternatively, it is prepared from the reaction of dimethyl sulfate with potassium iodide in the presence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echothiophate Synthesis
Echothiophate (Phospholine) is an irreversible acetylcholinesterase inhibitor. Uses It is used as an ocular antihypertensive in the treatment of open angle glaucoma and, in some cases, accommodative esotropia. It is available under several trade names such as Phospholine Iodide ( Wyeth-Ayerst). Echothiophate binds irreversibly to cholinesterase. Because of the very slow rate at which echothiophate is hydrolyzed by cholinesterase, its effects can last a week or more. Adverse effects include muscle spasm and other systemic effects. Mechanism of action It covalently binds by its phosphate group to serine group at the active site of the cholinesterase. Once bound, the enzyme is permanently inactive and the cell has to make new enzymes. Shortage Wyeth Pharmaceuticals stopped manufacturing echothiophate iodide in the US in 2003. After contacting the American Academy of Ophthalmology (AAO), Wyeth rescinded their decision and, according to AAO public relations representative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
