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Reproterol
Reproterol is a short-acting Beta2-adrenergic agonist, β2 adrenoreceptor agonist used in the treatment of asthma. It was patented in 1965 and came into medical use in 1977. Stereochemistry Reproterol contains a stereocenter and is chirality (chemistry) , chiral. There are thus two enantiomers, the (''R'')-form and the (''S'')-form. The commercial preparations contain the drug as a racemate, an equal mixture of the two enantiomers. References Antiasthmatic drugs Beta-adrenergic agonists Xanthines Phenylethanolamines Resorcinols {{respiratory-system-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-adrenergic Agonists
Beta adrenergic agonists or beta agonists are medications that relax muscles of the airways, causing widening of the airways and resulting in easier breathing. They are a class of sympathomimetic agents, each acting upon the Adrenergic receptor#β receptors, beta adrenoceptors. In general, pure beta-adrenergic agonists have the opposite function of beta blockers: beta-adrenoreceptor agonist ligands mimic the actions of both epinephrine- and norepinephrine- signaling, in the heart and lungs, and in smooth muscle tissue; epinephrine expresses the higher affinity. The activation of β1, β2 and β3 activates the enzyme, Adenylyl cyclase, adenylate cyclase. This, in turn, leads to the activation of the secondary messenger cyclic adenosine monophosphate (cAMP); cAMP then activates protein kinase A (PKA) which phosphorylates target proteins, ultimately inducing smooth muscle relaxation and contraction of the cardiac tissue. Function Activation of β1 receptors induces positive inot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metered-dose Inhaler
A metered-dose inhaler (MDI) is a device that delivers a specific amount of medication to the lungs in the form of a short burst of aerosolized medicine that is usually self-administered by the patient via inhalation. It is the most commonly used delivery system for treating asthma, chronic obstructive pulmonary disease (COPD) and other respiratory diseases. The medication in a metered dose inhaler is most commonly a bronchodilator, corticosteroid or a combination of both for treating asthma and COPD. Other medications less commonly used but also administered by MDI are mast cell stabilizers, such as cromoglicate or nedocromil. Description A metered-dose inhaler consists of three major components: the canister, which is produced in aluminum or stainless steel by means of deep drawing, where the formulation resides; the metering valve, which allows a metered quantity of the formulation to be dispensed with each actuation; and an actuator (or mouthpiece) which enables the patien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravenous Therapy
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 per os, by mouth. It may also be used to administer pharmaceutical drug, medications or other medical therapy such as blood transfusion, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta2-adrenergic Agonist
Beta2-adrenergic agonists, also known as adrenergic β2 receptor agonists, are a class of drugs that act on the β2 adrenergic receptor. Like other β adrenergic agonists, they cause smooth muscle relaxation. β2 adrenergic agonists' effects on smooth muscle cause dilation of bronchial passages, vasodilation in muscle and liver, relaxation of uterine muscle, and release of insulin. They are primarily used to treat asthma and other pulmonary disorders. Bronchodilators are considered an important treatment regime for chronic obstructive pulmonary disease (COPD) and are usually used in combination with short acting medications and long acting medications in a combined inhaler. Mechanism of action Activation of β adrenergic receptors leads to relaxation of smooth muscle in the lung, and dilation and opening of the airways. β adrenergic receptors are coupled to a stimulatory G protein of adenylyl cyclase. This enzyme produces the second messenger cyclic adenosine monoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asthma
Asthma is a common long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. A sudden worsening of asthma symptoms sometimes called an 'asthma attack' or an 'asthma exacerbation' can occur when allergens, pollen, dust, or other particles, are inhaled into the lungs, causing the bronchioles to constrict and produce mucus, which then restricts oxygen flow to the alveoli. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise. Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin and beta blockers. Diag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chirality (chemistry)
In chemistry, a molecule or ion is called chiral () if it cannot be superposed on its mirror image by any combination of rotations, translations, and some conformational changes. This geometric property is called chirality (). The terms are derived from Ancient Greek (''cheir'') 'hand'; which is the canonical example of an object with this property. A chiral molecule or ion exists in two stereoisomers that are mirror images of each other, called enantiomers; they are often distinguished as either "right-handed" or "left-handed" by their absolute configuration or some other criterion. The two enantiomers have the same chemical properties, except when reacting with other chiral compounds. They also have the same physical properties, except that they often have opposite optical activities. A homogeneous mixture of the two enantiomers in equal parts is said to be racemic, and it usually differs chemically and physically from the pure enantiomers. Chiral molecules will usually h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enantiomers
In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities which are mirror images of each other and non-superposable. Enantiomer molecules are like right and left hands: one cannot be superposed onto the other without first being converted to its mirror image. It is solely a relationship of chirality (chemistry), chirality and the permanent three-dimensional relationships among molecules or other chemical structures: no amount of re-orientation of a molecule as a whole or conformational isomerism, conformational change converts one chemical into its enantiomer. Chemical structures with chirality rotate plane-polarized light. A mixture of equal amounts of each enantiomer, a ''racemic mixture'' or a ''racemate'', does not rotate light. Stereoisomers include both enantiomers and diastereomers. Diaste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Racemate
In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as racemates. History The first known racemic mixture was racemic acid, which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid. He manually separated the crystals of a mixture, starting from an aqueous solution of the sodium ammonium salt of racemate tartaric acid. Pasteur benefited from the fact that ammonium tartrate salt gives enantiomeric crystals with distinct crystal forms (at 77 °F). Reasoning from the macroscopic scale down to the molecular, he reckoned that the molecules had to have non-superimposable mirror images. A sample with only a single enantiomer is an ''enantiomerically pure'' or ''enantiopure'' compound. Etymology The word ''racemic'' derives from Latin , meaning pertaining to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiasthmatic Drugs
An anti-asthmatic agent, also known as an anti-asthma drug, refers to a drug that can aid in airway smooth muscle bronchodilatation, dilation to allow normal breathing during an asthma attack or reduce inflammation on the airway to decrease airway resistance for asthma, asthmatic patients, or both. The goal of asthmatic agents is to reduce asthma exacerbation frequencies and related hospital visits. Anti-asthmatic agents as rescue medications for acute asthma attacks include short-acting beta2-adrenergic agonist, β2-adrenergic receptor agonists (SABA), short-acting muscarinic antagonists (SAMA), systemic administration, systemic glucocorticoids, and magnesium sulfate. Anti-asthmatic agents as maintenance medications for asthmatic symptom control include long-acting β2-adrenergic receptor agonists (LABA), inhalational administration, inhaled glucocorticoids, long-acting muscarinic antagonists (LAMA), methylxanthines/phosphodiesterase inhibitors, antileukotriene, leukotriene recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthines
Xanthine ( or , from Ancient Greek for its yellowish-white appearance; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base (genetics), base found in most human body tissues and fluids, as well as in other organisms. Several stimulants are derived from xanthine, including caffeine, theophylline, and theobromine. Xanthine is a product on the pathway of purine degradation. * It is created from guanine by guanine deaminase. * It is created from hypoxanthine by xanthine oxidoreductase. * It is also created from xanthosine by purine nucleoside phosphorylase. Xanthine is subsequently converted to uric acid by the action of the xanthine oxidase enzyme. Use and production Xanthine is used as a drug precursor (chemistry), precursor for human and animal medications, and is produced as a pesticide ingredient. Clinical significance Derivatives of xanthine (known collectively as xanthines) are a group of alkaloids commonly used for their effects as mild ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
