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Drug Sensitization
Reverse tolerance or drug sensitization is a pharmacological phenomenon describing subjects' increased reaction (positive or negative) to a drug following its repeated use. Not all drugs are subject to reverse tolerance. This is the opposite of drug tolerance, in which the effect or the subject's reaction decreases following its repeated use. The two notions are not incompatible, and tolerance may sometimes lead to reverse tolerance. For example, heavy drinkers initially develop tolerance to alcohol, requiring them to drink larger amounts to achieve a similar effect, but as excessive drinking can cause liver damage, this can then put this group at risk of intoxication when drinking even very small amounts of alcohol. Sensitization, a form of reverse tolerance, develops rapidly to the positive, euphoric effects of alcohol, but not to the physical effects, such as sedation and respiratory depression, which diminish with prolonged use. This sensitization does not occur, however, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmacology
Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemical or physiological effect on the cell, tissue, organ, or organism (sometimes the word ''pharmacon'' is used as a term to encompass these endogenous and exogenous Biological activity, bioactive species). More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered Pharmaceutical drug, pharmaceuticals. The field encompasses drug composition and properties,functions,sources,synthesis and drug design, molecular and cellular mechanism of action, mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, drug interaction, interactions, chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Tolerance
Drug tolerance or drug insensitivity is a pharmacological concept describing subjects' reduced reaction to a drug following its repeated use. Increasing its dosage may re-amplify the drug's effects; however, this may accelerate tolerance, further reducing the drug's effects. Drug tolerance is indicative of drug use but is not necessarily associated with drug dependence or addiction. The process of tolerance development is reversible (e.g., through a drug holiday) and can involve both physiological factors and psychological factors. One may also develop drug tolerance to side effects, in which case tolerance is a desirable characteristic. A medical intervention that has an objective to increase tolerance (e.g., allergen immunotherapy, in which one is exposed to larger and larger amounts of allergen to decrease one's allergic reactions) is called drug desensitization. The opposite concept to drug tolerance is drug reverse tolerance (or drug sensitization), in which case the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liver Damage
Liver disease, or hepatic disease, is any of many diseases of the liver. If long-lasting it is termed chronic liver disease. Although the diseases differ in detail, liver diseases often have features in common. Signs and symptoms Some of the signs and symptoms of a liver disease are the following: * Jaundice * Confusion and altered consciousness caused by hepatic encephalopathy. * Thrombocytopenia and coagulopathy. * Risk of bleeding symptoms particularly taking place in gastrointestinal tract Liver diseases File:Ground glass hepatocytes high mag cropped 2.jpg, Ground glass hepatocytes File:Primary biliary cirrhosis intermed mag much cropping.jpg, Primary biliary cirrhosis File:Buddchiari2.PNG, Budd-chiari syndrome File:Non-alcoholic_fatty_liver_disease1.jpg, Micrograph of non-alcoholic fatty liver disease There are more than a hundred different liver diseases. Some of the most common are: * Fascioliasis, a parasitic infection of liver caused by a liver fluke of the genus ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desensitization (medicine)
In medicine, desensitization is a method to reduce or eliminate an organism's negative reaction to a substance or stimulus. In pharmacology, ''drug desensitization'' refers to two related concepts. First, desensitization may be equivalent to drug tolerance and refers to subjects' reactions (positive or negative) to a drug reducing following its repeated use. This is a macroscopic, organism-level effect and differs from the second meaning of desensitization, which refers to a biochemical effect where individual receptors become less responsive after repeated application of an agonist. This may be mediated by phosphorylation, for instance by beta adrenoceptor kinase at the beta adrenoceptor. Application to allergies For example, if a person with diabetes mellitus has a bad allergic reaction to taking a full dose of beef insulin, the person is given a very small amount of the insulin at first, so small that the person has no adverse reaction or very limited symptoms as a res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downregulation And Upregulation
In the biological context of organisms' production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary process that involves increases of such components is called upregulation. An example of downregulation is the cellular decrease in the expression of a specific receptor in response to its increased activation by a molecule, such as a hormone or neurotransmitter, which reduces the cell's sensitivity to the molecule. This is an example of a locally acting (negative feedback) mechanism. An example of upregulation is the response of liver cells exposed to such xenobiotic molecules as dioxin. In this situation, the cells increase their production of cytochrome P450 enzymes, which in turn increases degradation of these dioxin molecules. Downregulation or upregulation of an RNA or protein may also arise by an epigenetic alteration. Such an epig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kindling (sedative–hypnotic Withdrawal)
Kindling due to substance withdrawal refers to the neurological condition which results from repeated withdrawal episodes from sedative– hypnotic drugs such as alcohol and benzodiazepines. Each withdrawal leads to more severe withdrawal symptoms than in previous episodes. Individuals who have had more withdrawal episodes are at an increased risk of very severe withdrawal symptoms, up to and including seizures and death. Long-term use of GABAergic-acting sedative–hypnotic drugs causes chronic GABA receptor downregulation as well as glutamate overactivity, which can lead to drug and neurotransmitter sensitization, central nervous system hyperexcitability, and excitotoxicity. Symptoms Binge drinking is believed to increase impulsivity due to altered functioning of prefrontal–subcortical and orbitofrontal circuits. Binge drinking in alcoholics who have undergone repeated detoxification is associated with an inability to interpret facial expressions properly; this is beli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
