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Echothiophate
Echothiophate (Phospholine) is an irreversible acetylcholinesterase inhibitor. Uses It is used as an ocular antihypertensive in the treatment of chronic 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 drug reaction, 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 After contacting the American Academy of Ophthalmology (AAO), Wyeth rescinded their decision and, according to AAO public relatio ... [...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 chronic 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 drug reaction, 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 After contacting the American Academy of Ophthalmology (AAO), Wyeth rescinded their decision and, according to AAO public relatio ... [...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 TEPP and sarin inhibit cholinesterases, enzymes that hydrolyze the neurotransmitter acetylcholine. The active centre of cholinesterases feature two important sites, namely the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholinesterase Inhibitors
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 TEPP and sarin inhibit cholinesterases, enzymes that hydrolyze the neurotransmitter acetylcholine. The active centre of cholinesterases feature two important sites, namely th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organothiophosphate Esters
Organothiophosphates or organophosphorothioates are a subclass of organophosphorus compounds. Many are used as pesticides, some have medical applications, and some are used as oil additives. They generally have the chemical formula (RO)3PS, RO)2P(S)Osup>−, R(RO)2PS, etc. Oligonucleotide phosphorothioates (OPS) are modified oligonucleotides where one of the oxygen atoms in the phosphate moiety is replaced by sulfur. These compounds are the basis of antisense therapy, e.g., the drugs fomivirsen (Vitravene), Oblimersen, Alicaforsen, and Mipomersen (Kynamro). Further examples of these include: * Diazinon * Fenitrothion * Fenthion * Thiotepa Variants with P=S double bonds were developed as insecticides because of their reduced mammalian toxicity. The phosphorothioate P=S bond is converted to the toxic P=O bond in the target insect. Similar oxidative conversion in mammals is slower, conferring lower toxicity in mammals. Structure and chemical synthesis Generally these compounds fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaucoma
Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for fluid within the eye remains open, with less common types including closed-angle (narrow angle, acute congestive) glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Peripheral vision may begin to decrease, followed by central vision, resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent. Eyes affected by glaucoma are referred to as being glaucomatous. Risk factors for glaucoma include increasing age, high pressure in the eye, a family history of glaucoma, and use of steroid medication. F ... [...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 to the ... [...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. Elevated intraocular pressure is an important risk factor for glaucoma. One study found that topical ocular hypotensive medication delays or prevents the onset of primary open-angle 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 The pressure within the eye is maintained by the balance between the fluid that enters the eye through the ciliary body and the fluid that exits the eye through the trabecular meshwork. Diagnosis The condition is diagnosed using ocular tonometry and glaucoma evaluation. Increased IOP without glaucomatous changes (in op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esotropia
Esotropia is a form of strabismus in which one or both eyes turns 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 prisms and/or orthopti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wyeth-Ayerst
Wyeth, LLC was an American pharmaceutical company. The company was founded in Philadelphia, Pennsylvania, in 1860 as ''John Wyeth and Brother''. It was later known, in the early 1930s, as American Home Products, before being renamed to Wyeth in 2002. Its headquarters moved to Collegeville, Pennsylvania and Madison, New Jersey, before they were consolidated with Pfizer's in New York City after the 2009 merger. Most of Wyeth's pharmaceutical assets were acquired by Pfizer in 2009, while its infant and maternal nutrition business was acquired by Nestlé in 2012. Wyeth manufactured over-the-counter drugs (OTCs) 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. ... [...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 butyrylcholinestera ... [...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 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 drug event (ADE) refers to any unexpected and inappropriate occurrence at the time a drug is used, whether or not associated with the administration of the drug. An ADR is a special type of ADE in which a causative relationship can be shown. ADRs are only one type of medication-related harm, as harm can also be caused by omitting to take indicated medications. Classification ADRs may be classified by e.g. cause and severity. Cause *Type A: Augmented pharmacologic effects - dose dependent and predictable :Type A reactions, which constitute approximate ... [...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 overload. There are other causes of involuntary muscle contractions, and some of these may cause a health problem. Description and causes Various kinds of involuntary muscle activity may be referred to as a "spasm". A spasm may be a muscle contraction caused by abnormal nerve stimulation or by abnormal activity of the muscle itself. A spasm may lead to muscle strains or tears in tendons and ligaments if the force of the spasm exceeds the tensile strength of the underlying connective tissue. This can occur with a particularly strong spasm or with weakened connective ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
