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Reverse Tolerance
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 the science of drugs and medications, including a substance's origin, composition, pharmacokinetics, pharmacodynamics, therapeutic use, and toxicology. 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 pharmaceuticals. The field encompasses drug composition and properties, functions, sources, synthesis and drug design, molecular and cellular mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, interactions, chemical biology, therapy, and medical applications and antipathogenic capabilities. The two main areas of pharmacology are pharmacodynamics and pharmacokinetics. Pharmacodynamics studies the effects of a drug on biological systems, and pharmacokinetics studies the effects of biological systems on a drug. In broad terms, pharmacod ... [...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 reverse tolerance, in which case the subject's reaction or effect wil ... [...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. 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 '' FascioIa'', mostly '' FascioIa hepatica''. * Hepatitis, inflammation of the liver, is caused by various viruses ( viral hepatitis) also by some liver toxins (e.g. alcoholic hepatitis), autoimmunity (autoimmune hepatitis) or hereditary conditions. * Alcoholic liver disease is a hepati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drug Holiday
A drug holiday (sometimes also called a drug vacation, medication vacation, structured treatment interruption, tolerance break, treatment break or strategic treatment interruption) is when a patient stops taking a medication(s) for a period of time; anywhere from a few days to many months or even years if the doctor or medical provider feels it is best for the patient. It is recommended not to discontinue any medication without the close supervision of the prescribing party as it is only for specific cases. Planned drug holidays are used in some fields of medicine. They are perhaps best known in HIV therapy, after a study suggested that stopping medication may stimulate the immune system to attack the virus. As of 2025, there is a scientific consensus against drug holiday for HIV. Another reason for drug holidays is to permit a drug to regain effectiveness after a period of continuous use, and to reduce the tolerance effect that may require increased dosages. In addition to drug ... [...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 receptor (biochemistry), 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 allergy, allergic reaction to taking a full Dose (biochemistry), dose of beef insulin, the person is given a very small amount of the insulin at first, so small that the person has no adve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downregulation And Upregulation
In biochemistry, in the biological context of organisms' regulation of gene expression and production of gene products, downregulation is the process by which a cell decreases the production and quantities of its cellular components, such as RNA and proteins, in response to an external stimulus. The complementary process that involves increase in quantities of cellular 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kindling (sedative–hypnotic Withdrawal)
Kindling due to substance withdrawal is 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 activation of the GABA receptor by 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 believ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
