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Caffeinated
Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class and is the most commonly consumed psychoactive substance globally. It is mainly used for its eugeroic (wakefulness promoting), ergogenic (physical performance-enhancing), or nootropic (cognitive-enhancing) properties. Caffeine acts by blocking the binding of adenosine at a number of adenosine receptor types, inhibiting the centrally depressant effects of adenosine and enhancing the release of acetylcholine. Caffeine has a three-dimensional structure similar to that of adenosine, which allows it to bind and block its receptors. Caffeine also increases cyclic AMP levels through nonselective inhibition of phosphodiesterase, increases calcium release from intracellular stores, and antagonizes GABA receptors, although these mechanisms typically occur at concentrations beyond usual human consumption. Caffeine is a bitter, white crystalline purine, a methylxanthine alkaloid, and is chemically relate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Dependence
Physical dependence is a physical condition caused by chronic use of a tolerance-forming drug, in which abrupt or gradual drug withdrawal causes unpleasant physical symptoms. Physical dependence can develop from low-dose therapeutic use of certain medications such as benzodiazepines, opioids, stimulants, antiepileptics and antidepressants, as well as the recreational misuse of drugs such as alcohol, opioids and benzodiazepines. The higher the dose used, the greater the duration of use, and the earlier age use began are predictive of worsened physical dependence and thus more severe withdrawal syndromes. Acute withdrawal syndromes can last days, weeks or months. Protracted withdrawal syndrome, also known as post-acute-withdrawal syndrome or "PAWS", is a low-grade continuation of some of the symptoms of acute withdrawal, typically in a remitting-relapsing pattern, often resulting in relapse and prolonged disability of a degree to preclude the possibility of lawful employment. Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Over-the-counter Drug
Over-the-counter (OTC) drugs are medicines sold directly to a consumer without a requirement for a prescription from a healthcare professional, as opposed to prescription drugs, which may be supplied only to consumers possessing a valid prescription. In many countries, OTC drugs are selected by a regulatory agency to ensure that they contain ingredients that are safe and effective when used without a physician's care. OTC drugs are usually regulated according to their active pharmaceutical ingredient (API) and strengths of final products. The term ''over-the-counter'' (''OTC'') refers to a medication that can be purchased without a medical prescription. In contrast, prescription drugs require a prescription from a doctor or other health care professional and should only be used by the prescribed individual. Some drugs may be legally classified as over-the-counter (i.e. no prescription is required), but may only be dispensed by a pharmacist after an assessment of the patient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Classification
Chemical classification systems attempt to classify elements or compounds according to certain chemical functional or structural properties. Whereas the structural properties are largely intrinsic, functional properties and the derived classifications depend to a certain degree on the type of chemical interaction partners on which the function is exerted. Sometimes other criteria like purely physical ones (e.g. molecular weight) or – on the other hand – functional properties above the chemical level are also used for building chemical taxonomies. Some systems mix the various levels, resulting in hierarchies where the domains are slightly confused, for example having structural and functional aspects end up on the same level. Whereas chemical function is closely dependent on chemical structure, the situation becomes more involved when e.g. pharmacological function is integrated, because the QSAR can usually not be directly computed from structural qualities. Physico-chem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylxanthine
Methylxanthines are chemical compounds which are derivatives of xanthine with one or more methyl groups, including: One methyl group: * 1-Methylxanthine * 3-Methylxanthine * 7-Methylxanthine Two methyl groups: * Theophylline (1,3-dimethylxanthine) * Paraxanthine (1,7-dimethylxanthine) * Theobromine (3,7-dimethylxanthine) Three methyl groups: * Caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine chemical classification, class and is the most commonly consumed Psychoactive drug, psychoactive substance globally. It is mainly used for its eugeroic (wakefulness pr ... (1,3,7-trimethylxanthine) General references * {{chemistry index ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stimulant
Stimulants (also known as central nervous system stimulants, or psychostimulants, or colloquially as uppers) are a class of drugs that increase alertness. They are used for various purposes, such as enhancing attention, motivation, cognition, Mood disorder, mood, and physical activity, physical performance. Some stimulants occur naturally, while others are exclusively synthetic. Common stimulants include caffeine, nicotine, amphetamines, cocaine, methylphenidate, and modafinil. Stimulants may be subject to varying forms of regulation, or outright prohibition, depending on jurisdiction. Stimulants increase activity in the sympathetic nervous system, either directly or indirectly. Prototypical stimulants increase synaptic concentrations of neurotransmitter, excitatory neurotransmitters, particularly norepinephrine and dopamine (e.g., methylphenidate). Other stimulants work by binding to the Receptor (biochemistry), receptors of excitatory neurotransmitters (e.g., nicotine) or by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilateria, bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and Coelenterata, diploblasts. It is a structure composed of nervous tissue positioned along the Anatomical_terms_of_location#Rostral,_cranial,_and_caudal, rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain, though precursor structures exist in onychophorans, gastropods and lancelets. The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sublimation (chemistry)
Sublimation is the Phase transition, transition of a substance directly from the solid to the gas state, without passing through the liquid state. The verb form of sublimation is ''sublime'', or less preferably, ''sublimate''. ''Sublimate'' also refers to the product obtained by sublimation. The point at which sublimation occurs rapidly (for further details, see #False correspondence with vaporization, below) is called critical sublimation point, or simply sublimation point. Notable examples include sublimation of dry ice at room temperature and atmospheric pressure, and that of solid iodine with heating. The reverse process of sublimation is deposition (phase transition), ''deposition'' (also called ''desublimation''), in which a substance passes directly from a gas to a solid phase, without passing through the liquid state. Technically, all solids may sublime, though most sublime at extremely low rates that are hardly detectable under usual conditions. At standard condi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theophylline
Theophylline, also known as 1,3-dimethylxanthine, is a drug that inhibits phosphodiesterase and blocks adenosine receptors. It is used to treat chronic obstructive pulmonary disease (COPD) and asthma. Its pharmacology is similar to other methylxanthine drugs (e.g., theobromine and caffeine). Trace amounts of theophylline are naturally present in tea, coffee, chocolate, yerba maté, guarana, and kola nut. The name 'theophylline' derives from "Thea"—the former genus name for tea + Legacy Greek φύλλον (phúllon, "leaf") + -ine. Medical uses The main actions of theophylline involve: * relaxing bronchial smooth muscle * increasing heart muscle contractility and efficiency (positive inotrope) * increasing heart rate (positive chronotropic) * increasing blood pressure * increasing renal blood flow * anti-inflammatory effects * central nervous system stimulatory effect, mainly on the medullary respiratory center The main therapeutic uses of theophylline are for treat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theobromine
Theobromine, also known as xantheose, is the principal alkaloid of ''Theobroma cacao'' (cacao plant). Theobromine is slightly water-soluble (330 mg/L) with a bitter taste. In industry, theobromine is used as an additive and precursor to some cosmetics. It is found in chocolate, as well as in a number of other foods, including tea (''Camellia sinensis''), some American hollies ( yaupon and guayusa) and the kola nut. It is a white or colourless solid, but commercial samples can appear yellowish. Theobromine, a metabolite of caffeine, is processed in the liver into xanthine and methyluric acid, peaks in the blood 2–3 hours after ingestion due to its fat solubility, and primarily acts by inhibiting adenosine receptors with minor phosphodiesterase inhibition. It is a mild heart stimulant and bronchodilator in humans with limited central nervous system effects. It can be toxic or fatal to animals like dogs and cats due to their slower metabolism of the compound. Structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraxanthine
Paraxanthine, also known as 1,7-dimethylxanthine, is an isomer of theophylline and theobromine, two well-known stimulants found in coffee, tea, and chocolate, mainly in the form of caffeine. It is a member of the xanthine family of alkaloids, which also includes theophylline and theobromine in addition to caffeine. Production and metabolism Paraxanthine is not known to be produced by plants but is observed in nature as a metabolite of caffeine in animals and some species of bacteria. Paraxanthine is the primary metabolite of caffeine in humans and other animals, such as mice. Shortly after ingestion, roughly 84% of caffeine is metabolized into paraxanthine by hepatic cytochrome P450, which removes a methyl group from the N3 position of caffeine. After formation, paraxanthine can be broken down to 7-methylxanthine by demethylation of the N1 position, which is subsequently demethylated into xanthine or oxidized by CYP2A6 and CYP1A2 into 1,7-dimethyluric acid. In another pat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CYP2C9
Cytochrome P450 family 2 subfamily C member 9 (abbreviated CYP2C9) is an enzyme protein. The enzyme is involved in the metabolism, by oxidation, of both xenobiotics, including drugs, and endogenous compounds, including fatty acids. In humans, the protein is encoded by the ''CYP2C9'' gene. The gene is highly polymorphic, which affects the efficiency of the metabolism by the enzyme. Function CYP2C9 is a crucial cytochrome P450 enzyme, which plays a significant role in the metabolism, by oxidation, of both xenobiotic and endogenous compounds. CYP2C9 makes up about 18% of the cytochrome P450 protein in liver microsomes. The protein is mainly expressed in the liver, duodenum, and small intestine. About 100 therapeutic drugs are metabolized by CYP2C9, including drugs with a narrow therapeutic index such as warfarin and phenytoin, and other routinely prescribed drugs such as acenocoumarol, tolbutamide, losartan, glipizide, and some nonsteroidal anti-inflammatory drugs. By contra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CYP2C8
Cytochrome P4502C8 (CYP2C8) is a member of the cytochrome P450 mixed-function oxidase system involved in the metabolism of xenobiotics in the body. Cytochrome P4502C8 also possesses epoxygenase activity, i.e. it metabolizes long-chain polyunsaturated fatty acids, e.g. arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and linoleic acid to their biologically active epoxides. Ligands Following is a table of selected substrates, inducers and inhibitors of 2C8. Inhibitors of CYP2C8 can be classified by their potency, such as: * Strong inhibitor being one that causes at least a five-fold increase in the plasma AUC values, or more than 80% decrease in clearance. * Moderate inhibitor being one that causes at least a two-fold increase in the plasma AUC values, or 50-80% decrease in clearance. * Weak inhibitor being one that causes at least a 1.25-fold but less than two-fold increase in the plasma AUC values, or 20-50% decrease in clearance. Retrieved on July 2011 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
