{"id":658,"date":"2019-10-17T08:43:48","date_gmt":"2019-10-17T08:43:48","guid":{"rendered":"http:\/\/human-memory.net\/?p=658"},"modified":"2022-05-20T09:46:50","modified_gmt":"2022-05-20T09:46:50","slug":"antagonists","status":"publish","type":"post","link":"https:\/\/human-memory.net\/antagonists\/","title":{"rendered":"Antagonists"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_17 counter-hierarchy counter-decimal ez-toc-grey\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" style=\"display: none;\"><i class=\"ez-toc-glyphicon ez-toc-icon-toggle\"><\/i><\/a><\/span><\/div>\n<nav><ul class=\"ez-toc-list ez-toc-list-level-1\"><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/human-memory.net\/antagonists\/#Boost_Your_Brain_with_Mind_Lab_Pro\" title=\"\n\t\tBoost Your Brain with Mind Lab Pro\n\t\">\n\t\tBoost Your Brain with Mind Lab Pro\n\t<\/a><ul class=\"ez-toc-list-level-3\"><li class=\"ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/human-memory.net\/antagonists\/#Benefits\" title=\"\n\t\tBenefits\n\t\">\n\t\tBenefits\n\t<\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/human-memory.net\/antagonists\/#Types\" title=\"Types \">Types <\/a><ul class=\"ez-toc-list-level-3\"><li class=\"ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/human-memory.net\/antagonists\/#Chemical_Antagonists\" title=\"Chemical Antagonists\">Chemical Antagonists<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/human-memory.net\/antagonists\/#Physiological_Antagonist\" title=\"Physiological Antagonist\">Physiological Antagonist<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/human-memory.net\/antagonists\/#Pharmacological_Antagonist\" title=\"Pharmacological Antagonist\">Pharmacological Antagonist<\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/human-memory.net\/antagonists\/#Reversible_or_competitive_antagonist\" title=\"Reversible or competitive antagonist\">Reversible or competitive antagonist<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/human-memory.net\/antagonists\/#Irreversible_or_non-competitive_antagonist\" title=\"Irreversible or non-competitive antagonist\">Irreversible or non-competitive antagonist<\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/human-memory.net\/antagonists\/#Allosteric_Antagonist\" title=\"Allosteric Antagonist\">Allosteric Antagonist<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/human-memory.net\/antagonists\/#Physical_antagonist\" title=\"Physical&nbsp; antagonist\">Physical&nbsp; antagonist<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/human-memory.net\/antagonists\/#Inverse_agonists\" title=\"Inverse agonists \">Inverse agonists <\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/human-memory.net\/antagonists\/#Antagonist_important_in_CNS\" title=\"Antagonist important in CNS\">Antagonist important in CNS<\/a><ul class=\"ez-toc-list-level-3\"><li class=\"ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/human-memory.net\/antagonists\/#Dopamine_Antagonist\" title=\"Dopamine Antagonist \">Dopamine Antagonist <\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/human-memory.net\/antagonists\/#D1_blockers\" title=\"D1 blockers\">D1 blockers<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/human-memory.net\/antagonists\/#D2_blockers\" title=\"D2 blockers\">D2 blockers<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/human-memory.net\/antagonists\/#Uses\" title=\"Uses\">Uses<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/human-memory.net\/antagonists\/#Drugs\" title=\"Drugs\">Drugs<\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/human-memory.net\/antagonists\/#Serotonin_Antagonist\" title=\"Serotonin Antagonist\">Serotonin Antagonist<\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/human-memory.net\/antagonists\/#Uses-2\" title=\"Uses\">Uses<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/human-memory.net\/antagonists\/#Drugs-2\" title=\"Drugs\">Drugs<\/a><\/li><\/ul><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-2\"><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/human-memory.net\/antagonists\/#Antagonists_important_in_ANS\" title=\"Antagonists important in ANS\">Antagonists important in ANS<\/a><ul class=\"ez-toc-list-level-3\"><li class=\"ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/human-memory.net\/antagonists\/#Muscarinic_Antagonists\" title=\"Muscarinic Antagonists \">Muscarinic Antagonists <\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/human-memory.net\/antagonists\/#Uses-3\" title=\"Uses\">Uses<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/human-memory.net\/antagonists\/#Drugs-3\" title=\"Drugs\">Drugs<\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/human-memory.net\/antagonists\/#Nicotinic_Receptor_Antagonists\" title=\"Nicotinic Receptor Antagonists\">Nicotinic Receptor Antagonists<\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/human-memory.net\/antagonists\/#Ganglionic_blockers\" title=\"Ganglionic blockers\">Ganglionic blockers<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/human-memory.net\/antagonists\/#Neuromuscular_blocking_drugs\" title=\"Neuromuscular blocking drugs\">Neuromuscular blocking drugs<\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/human-memory.net\/antagonists\/#Alpha_Receptor_Antagonists\" title=\"Alpha Receptor Antagonists\">Alpha Receptor Antagonists<\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/human-memory.net\/antagonists\/#Alpha-1_blockers\" title=\"Alpha-1 blockers\">Alpha-1 blockers<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/human-memory.net\/antagonists\/#Alpha-2_blockers\" title=\"Alpha-2 blockers\">Alpha-2 blockers<\/a><\/li><\/ul><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/human-memory.net\/antagonists\/#Beta_Receptor_Antagonists\" title=\"Beta Receptor Antagonists \">Beta Receptor Antagonists <\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-3\"><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/human-memory.net\/antagonists\/#ConclusionSummary\" title=\"Conclusion\/Summary\">Conclusion\/Summary<\/a><ul class=\"ez-toc-list-level-4\"><li class=\"ez-toc-heading-level-4\"><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/human-memory.net\/antagonists\/#References\" title=\"References\">References<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n\n<h2><span class=\"ez-toc-section\" id=\"Boost_Your_Brain_with_Mind_Lab_Pro\"><\/span>\n\t\tBoost Your Brain with Mind Lab Pro\n\t<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\t<p><strong>Your brain is incredibly complex. Mind Lab Pro has 11 different nootropics all working together to increase your cognition and brainpower to help you live a better life.<\/strong><\/p>\n<p>If you need to perform at your best, need to focus, problem-solve or maintain a calm and clear mindset, you will get a huge benefit from taking Mind Lab Pro.<\/p>\n\t\t\t<a href=\"https:\/\/www.mindlabpro.com?a_aid=5f9802ef2d90f&amp;a_bid=6d45f5c3\" target=\"_blank\" role=\"button\" rel=\"noopener nofollow noreferrer\">\n\t\t\t\t\t\t\tTry Mind Lab Pro Today \u2192\n\t\t\t\t\t<\/a>\n\t\t\t\t<a href=\"https:\/\/takespruce.com\/product\/750mg-lab-grade-cbd-oil?rfsn=4424690.8df824\" target=\"_blank\" rel=\"noopener nofollow noreferrer\" itemprop=\"url\">\n\t\t\t\t<img data-recalc-dims=\"1\" height=\"281\" width=\"300\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2020\/11\/mind-lab-pro.png?resize=300%2C281&#038;ssl=1\" alt=\"mind-lab-pro\" itemprop=\"image\" title=\"mind-lab-pro\" onerror=\"this.style.display='none'\">\n\t\t\t\t<\/a>\n<h3><span class=\"ez-toc-section\" id=\"Benefits\"><\/span>\n\t\tBenefits\n\t<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\t<ul>\n<li>Better focus<\/li>\n<li>Calm mindset<\/li>\n<li>55+ memory and mood<\/li>\n<li>Performance focused athletes<\/li>\n<li>Student learning<\/li>\n<\/ul>\n\t<p>An <strong>antagonist <\/strong>is a type of ligand or drug that avoids or dampens a biological reaction. Upon binding to the receptor, it does not activate. <\/p>\n<p>Rather it tends to block the particular receptor. Sometimes, they are also referred to as blockers such as alpha-blockers or beta-blockers. <\/p>\n<p>In this article, we will discuss different types of antagonists and the mechanisms of how they work.&nbsp; We will also discuss specific antagonists in detail that have special importance in neurology.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Types\"><\/span>Types <span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Antagonists<\/strong> can be classified into different categories depending on the mechanism they use to antagonize a particular biological response. They can also be classified de[ending on the type of receptor.<\/p>\nHere, we will discuss different types of antagonists<br>\ndepending upon their mechanism of action.\n<h3><span class=\"ez-toc-section\" id=\"Chemical_Antagonists\"><\/span>Chemical Antagonists<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/protamine-sulfate.jpg?resize=270%2C270\" alt=\"\" width=\"270\" height=\"270\"><\/figure>\n<p>It is a type of antagonist that binds to a drug or ligand and renders it ineffective. A chemical antagonist does so by causing certain chemical changes in the ligand it binds. <\/p>\n<p>The antagonist binds to the agonist and forms an inactive complex that cannot perform any function.<\/p>\n<p>For example, <strong>protamine sulfate<\/strong> is a positively charged drug. When it is given IV, it binds to heparin; a negatively charged drug, forming an inactive complex. As a result, heparin cannot perform its function. <\/p>\n<h3><span class=\"ez-toc-section\" id=\"Physiological_Antagonist\"><\/span>Physiological Antagonist<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/insulin.jpg?fit=1024%2C683&amp;ssl=1\" alt=\"\" width=\"510\" height=\"339\"><\/figure>\n<p>It is a type of antagonist that <strong>binds to a separate receptor<\/strong> and counters the effect of the agonist. Two drugs would be said physiological antagonists of one another, if they bind to two different receptors and produce opposite effects.<\/p>\nFor example, insulin and glucagon are physiological<br>\nantagonists of one another. Both of them bind to two different receptors, but<br>\nthe effects produced by each of them are opposite to each other. Insulin<br>\ndecreases blood glucose levels while glucagon increases it.\n<h3><span class=\"ez-toc-section\" id=\"Pharmacological_Antagonist\"><\/span>Pharmacological Antagonist<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Pharmacological antagonist<\/strong> binds to the same receptor as the agonist does. It occupies the binding site of the receptor and prevents the binding of agonist to the receptor. In this way, it prevents the activation of the receptor. These include receptor blockers such as alpha-blockers, beta-blockers, etc.<\/p>\nDepending on the fact that whether their effect can be<br>\ncountered or not, pharmacological antagonists are further divided into two<br>\ntypes:\n<h4><span class=\"ez-toc-section\" id=\"Reversible_or_competitive_antagonist\"><\/span>Reversible or competitive antagonist<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/prazosin.png?resize=407%2C219\" alt=\"\" width=\"407\" height=\"219\"><\/figure>\nIt is a type of pharmacological antagonist whose<br>\neffect can be countered by increasing the concentration of agonist. \nFor example, prazosin is a reversible antagonist of<br>\nalpha-1 receptors.\n<h4><span class=\"ez-toc-section\" id=\"Irreversible_or_non-competitive_antagonist\"><\/span>Irreversible or non-competitive antagonist<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i1.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/phenoxybenzamine.png?fit=1024%2C523&amp;ssl=1\" alt=\"\" width=\"371\" height=\"190\"><\/figure>\nIt is a type of pharmacological antagonist whose<br>\neffects cannot be countered by increasing the concentration of agonist.\n<p>For example, <strong>phenoxybenzamine<\/strong> is an irreversible antagonist of alpha-receptors.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Allosteric_Antagonist\"><\/span>Allosteric Antagonist<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>It is a type of antagonist that binds to the receptors but on a different as compared to the binding site of the real agonist. Binding of <strong>allosteric antagonist<\/strong> induces changes in the receptor. <\/p>\n<p>This type of antagonist can prevent the activation of receptor even after binding of the agonist. They can also change shape of the binding site in such a way that it no longer binds to the agonist.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Physical_antagonist\"><\/span>Physical&nbsp; antagonist<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i2.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/charcoal.jpg?fit=1024%2C683&amp;ssl=1\" alt=\"\" width=\"350\" height=\"232\"><\/figure>\nIt is a type of antagonist that is based on the<br>\nphysical property of the drug. It can bind to the agonist and prevent its<br>\naction. \nFor example, when charcoal is used in case of poison<br>\ningestion, such as alkaloid poisons; it acts as a physical antagonist. It has<br>\nthe ability to absorb the poison. In this way, it prevents the poison from<br>\nentering the bloodstream, thus countering it.\n<h3><span class=\"ez-toc-section\" id=\"Inverse_agonists\"><\/span>Inverse agonists <span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img data-recalc-dims=\"1\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/beta-carbolines.png?w=1200\" alt=\"\"><\/figure>\n<p>Although sounds more like an agonist, an inverse agonist is a special type of antagonist. An <strong>inverse agonist <\/strong>binds to the same receptor as the agonist does. However, instead of increasing the activity of the receptor, an inverse agonist decreases it. <\/p>\nInverse<br>\nagonist works only when the receptor has some intrinsic activity. In that case,<br>\nthe binding of an agonist increases the intrinsic activity of the receptor<br>\nwhereas binding of an inverse agonist decreases it.\n<p><strong>GABA<\/strong><sub><strong>A<\/strong><\/sub><strong> receptors <\/strong>have intrinsic activity. Agonists of GABA<sub>A<\/sub> receptors include muscimol, whereas certain beta-carbolines act as inverse agonists of GABA<sub>A <\/sub>receptors.&nbsp; <\/p>\n<h2><span class=\"ez-toc-section\" id=\"Antagonist_important_in_CNS\"><\/span>Antagonist important in CNS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>In this section, we will discuss some antagonists that have particular importance in the <strong>central nervous system<\/strong>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dopamine_Antagonist\"><\/span>Dopamine Antagonist <span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Dopamine antagonists<\/strong> block the action of dopamine. They have profound importance in several antipsychotic diseases such as schizophrenia, bipolar disorder, and psychosis. They are also used in non-psychotic illnesses such as orthostatic hypotension, vomiting, and nausea.<\/p>\nDopamine<br>\nantagonists can be classified into two types;\n<h4><span class=\"ez-toc-section\" id=\"D1_blockers\"><\/span>D1 blockers<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/substantia-nigra.png?resize=379%2C210\" alt=\"\" width=\"379\" height=\"210\"><\/figure>\n<p>They block the <strong>D1-like receptors.<\/strong> They include D1 and D5 receptors. These are the stimulatory receptors coupled with G<sub>s<\/sub> proteins. <\/p>\n<p>They are present in substantia nigra, and the direct pathway of the basal ganglia. They are peripherally present in the renal artery, mesenteric artery and splenic artery. <\/p>\n<h4><span class=\"ez-toc-section\" id=\"D2_blockers\"><\/span>D2 blockers<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i2.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/Gi-proteins.png?fit=1024%2C724&amp;ssl=1\" alt=\"\" width=\"414\" height=\"293\"><\/figure>\n<p>They block the D2 like receptors that include D2, D3, and D4 receptors. These are the inhibitory receptors coupled to<strong> G<\/strong><sub><strong>i<\/strong><\/sub><strong> proteins<\/strong>. <\/p>\n<p>They are present in presynaptic and postsynaptic neurons, striatum, substantia nigra, indirect pathway of basal ganglia. Peripherally, they are present in kidneys, adrenal cortex, and arteries. <\/p>\nMost<br>\nof the dopamine antagonists are non-specific. They can block both D1-like and<br>\nD2-like receptors.\n<h4><span class=\"ez-toc-section\" id=\"Uses\"><\/span>Uses<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/antipsychotic-drugs.jpg?resize=493%2C327\" alt=\"\" width=\"493\" height=\"327\"><\/figure>\nDopamine<br>\nantagonists are also known as typical antipsychotic drugs. They are used in<br>\ndifferent psychotic conditions such as:\n<ul>\n<li>Schizophrenia<\/li>\n<li>Mania<\/li>\n<li>Bipolar disorder<\/li>\n<li>Severe psychosis<\/li>\n<\/ul>\nThey<br>\nare also used in different non-psychotic diseases such as \n<ul>\n<li>Vomiting<\/li>\n<li>Nausea<\/li>\n<li>Hyperkinetic disorders<\/li>\n<li>Hypertension<\/li>\n<\/ul>\n<h4><span class=\"ez-toc-section\" id=\"Drugs\"><\/span>Drugs<span class=\"ez-toc-section-end\"><\/span><\/h4>\nDopamine<br>\nantagonists include drugs such as haloperidol, chlorpromazine, fluphenazine,<br>\netc.\n<h3><span class=\"ez-toc-section\" id=\"Serotonin_Antagonist\"><\/span>Serotonin Antagonist<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/Serotonin.png?resize=338%2C245\" alt=\"\" width=\"338\" height=\"245\"><\/figure>\n<p>As the name indicates, they block the activation of<strong> serotonin receptors<\/strong>. Serotonin antagonists have profound application in a number of psychiatric diseases such as depression, anxiety, insomnia, etc. <\/p>\nDifferent<br>\ntypes of serotonin receptors are present in the body. However, with respect to<br>\nthe brain, 5HT<sub>2<\/sub> are the most important. \nThe<br>\n5HT<sub>2<\/sub> receptors are widely distributed in the cortex, basal ganglia,<br>\nthe limbic system, and other areas of the brain. They are G-protein coupled<br>\nreceptors that are coupled to G<sub>q<\/sub> proteins. These are the stimulatory<br>\nreceptors. They are associated with increased neuronal activity in the brain.\n<h4><span class=\"ez-toc-section\" id=\"Uses-2\"><\/span>Uses<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i2.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/Schizophrenia.png?fit=1024%2C614&amp;ssl=1\" alt=\"\" width=\"497\" height=\"298\"><\/figure>\nThese<br>\ndrugs are called novel or atypical antipsychotic drugs. Like dopamine<br>\nantagonists, they are used in conditions like;\n<ul>\n<li>Schizophrenia<\/li>\n<li>Mania<\/li>\n<li>Bipolar disorder<\/li>\n<li>Severe psychosis<\/li>\n<\/ul>\nThese<br>\ndrugs have less severe side effects as compared to dopamine antagonists.\n<h4><span class=\"ez-toc-section\" id=\"Drugs-2\"><\/span>Drugs<span class=\"ez-toc-section-end\"><\/span><\/h4>\nSerotonin<br>\n5HT<sub>2<\/sub> receptor antagonists include clozapine, olanzapine,<br>\nrisperidone, apiprazole etc. \n<h2><span class=\"ez-toc-section\" id=\"Antagonists_important_in_ANS\"><\/span>Antagonists important in ANS<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/autonomic-nervous-system.jpg?fit=1024%2C576&amp;ssl=1\" alt=\"\" width=\"558\" height=\"313\"><\/figure>\nIn<br>\nthis section, we will discuss antagonists that are important in the autonomic<br>\nnervous system.\n<h3><span class=\"ez-toc-section\" id=\"Muscarinic_Antagonists\"><\/span>Muscarinic Antagonists <span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>The <strong>muscarinic receptor<\/strong> antagonists bind to acetylcholine receptors and prevent their activation. As acetylcholine is the main neurotransmitter of the parasympathetic system, these antagonists can successfully block the entire parasympathetic activation.<\/p>\nThere<br>\nare three types of muscarinic receptors;\n<ol>\n<li>M1 receptors, excitatory receptors present in brain<\/li>\n<li>M2 receptors, inhibitory receptors present in heart<\/li>\n<li>M3 receptors, excitatory receptors present inn smooth muscles, glands, eyes, etc.<\/li>\n<\/ol>\nAll<br>\nthese receptors are G-protein coupled receptors. M1 and M3 are G<sub>q<\/sub>-coupled<br>\nwhile M2 are G<sub>i<\/sub>-coupled receptors.\nAll<br>\nthe muscarinic antagonists are non-specific in nature and block all types of<br>\nreceptors. \n<h4><span class=\"ez-toc-section\" id=\"Uses-3\"><\/span>Uses<span class=\"ez-toc-section-end\"><\/span><\/h4>\nMuscarinic<br>\nantagonists find a number of uses. These include the following;\n<ul>\n<li>Management of AChE inhibitors overdose<\/li>\n<li>Ophthalmology (dilation of pupil)<\/li>\n<li>Asthma and COPD<\/li>\n<li>Motion sickness<\/li>\n<li>Overreactive bladder<\/li>\n<li>Anti-spasmodic<\/li>\n<li>Antidiarrheal<\/li>\n<\/ul>\n<h4><span class=\"ez-toc-section\" id=\"Drugs-3\"><\/span>Drugs<span class=\"ez-toc-section-end\"><\/span><\/h4>\nThe<br>\ndrugs in this category include atropine, benztropine, ipratropium, scopolamine,<br>\netc.\n<h3><span class=\"ez-toc-section\" id=\"Nicotinic_Receptor_Antagonists\"><\/span>Nicotinic Receptor Antagonists<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/skeletal-muscle.jpg?resize=522%2C293\" alt=\"\" width=\"522\" height=\"293\"><\/figure>\nThese<br>\nantagonists block the activation of nicotinic receptors present in ganglia and<br>\nskeletal muscle. Thus, they are further classified into two types;\n<h4><span class=\"ez-toc-section\" id=\"Ganglionic_blockers\"><\/span>Ganglionic blockers<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>These antagonists block the <strong>nicotinic receptors <\/strong>present in ganglia. Thus, they are able to block sympathetic as well as parasympathetic firing. It is because the ganglia of both these system have nicotinic receptors. <\/p>\n<p>They reduce the predominant autonomic tone. In the case of arterioles, venules and sweat glands, they block the sympathetic tone; while in other organs, they block the parasympathetic tone.<\/p>\nTwo<br>\nimportant ganglionic blockers include hexamethonium and mecamylamine.\n<h4><span class=\"ez-toc-section\" id=\"Neuromuscular_blocking_drugs\"><\/span>Neuromuscular blocking drugs<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<p>They block the nicotinic receptors present at n<strong>euromuscular junction<\/strong>. They are used as skeletal muscle relaxants. These include tubocurarine, atracurium, etc.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Alpha_Receptor_Antagonists\"><\/span>Alpha Receptor Antagonists<span class=\"ez-toc-section-end\"><\/span><\/h3>\nThese<br>\ndrugs block the activation of alpha receptors.\nThey<br>\nare further classified depending on the type of alpha receptors they block. \n<h4><span class=\"ez-toc-section\" id=\"Alpha-1_blockers\"><\/span>Alpha-1 blockers<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<figure><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/tamsulosin.png?fit=1024%2C332&amp;ssl=1\" alt=\"\" width=\"491\" height=\"158\"><\/figure>\nThey<br>\nblock the alpha-1 receptors present in arteries, venules, eyes, bladder, etc.<br>\nthese include prazosin, tamsulosin, etc.\nThese<br>\ndrugs are used in:\n<ul>\n<li>Hypertension<\/li>\n<li>Urinary retention<\/li>\n<li>Dilation of eye<\/li>\n<li>Cardiovascular disorders<\/li>\n<\/ul>\n<h4><span class=\"ez-toc-section\" id=\"Alpha-2_blockers\"><\/span>Alpha-2 blockers<span class=\"ez-toc-section-end\"><\/span><\/h4>\nThey<br>\nblock the alpha-2 receptors present in the presynaptic nerve terminal. These<br>\ninclude drugs like methyl-dopa and clonidine. \nThey<br>\nare used in hypertension, especially for the management of hypertension in<br>\npregnancy. \n<h3><span class=\"ez-toc-section\" id=\"Beta_Receptor_Antagonists\"><\/span>Beta Receptor Antagonists <span class=\"ez-toc-section-end\"><\/span><\/h3>\n<figure><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" src=\"https:\/\/i0.wp.com\/human-memory.net\/wp-content\/uploads\/2019\/10\/esmolol.png?resize=240%2C270\" alt=\"\" width=\"240\" height=\"270\"><\/figure>\nThey<br>\nblock the beta-2 receptors. They are of two types;\n<ol>\n<li>Cardiocelective, they block only beta-1 receptors present in the heart.<\/li>\n<li>Non-cardioselective, they are non-selective block both beta-1 and beta 2 receptors. <\/li>\n<\/ol>\nThese<br>\ndrugs include esmolol, atenolol, propranolol, etc.\nThey<br>\nare used in angina, myocardial infarction, cardiac failure, asthma etc.\n<h3><span class=\"ez-toc-section\" id=\"ConclusionSummary\"><\/span>Conclusion\/Summary<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>An <strong>antagonist<\/strong> is a drug or ligand that tends to stop or impede a biological reaction. They produce effects opposite to that of the agonist.<\/p>\nThey<br>\nare of different types depending on their mechanism of action.\n<p>These&nbsp; include;<\/p>\n<ul>\n<li>Physical antagonists<\/li>\n<li>Chemical antagonists<\/li>\n<li>Physiological antagonists<\/li>\n<li>Pharmacological antagonists<\/li>\n<li>Allosteric antagonists<\/li>\n<\/ul>\nAn<br>\ninverse agonist is a special type of antagonist that decreases the intrinsic<br>\nactivity of a receptor.\nAntagonist<br>\nfind important applications in the CNS as well as the ANS.\nThe<br>\nimportant CNS antagonists include dopamine antagonists and serotonin<br>\nantagonists.\nThe<br>\nimportant ANS antagonists include muscarinic antagonists, nicotinic<br>\nantagonists, alpha-blockers and beta-blockers.\n<h4><span class=\"ez-toc-section\" id=\"References\"><\/span>References<span class=\"ez-toc-section-end\"><\/span><\/h4>\n<ol>\n<li><em>Aitkenhead AR, Rowbotham DJ, Smith<br>\nG. Textbook of Anaesthesia, 4th Edn.<\/em><\/li>\n<li><em>London: Churchill\u2013Livingstone, 2001<\/em><\/li>\n<li><em>Calvey TN, Williams NE. Principles<br>\nand Practice of Pharmacology for Anaesthetists,<\/em><\/li>\n<li><em>3rd Edn. Oxford: Blackwell<br>\nScientific Publications, 1997<\/em><\/li>\n<li><em>Kenakin T. Pharmacologic Analysis<br>\nof Drug\u2013Receptor Interaction. Philadelphia:<\/em><\/li>\n<li><em>Lippincott-Raven, 1997<\/em><\/li>\n<li><em>Rang HP, Dale MM, Ritter JM, Moore<br>\nPK. Pharmacology, 5th Edn. London:<\/em><\/li>\n<li><em>Churchill\u2013Livingstone, 2003<\/em><\/li>\n<li><a href=\"https:\/\/www.sciencedirect.com\/topics\/medicine-and-dentistry\/dopamine-antagonist\" target=\"_blank\" rel=\"noopener\"><em>https:\/\/www.sciencedirect.com\/topics\/medicine-and-dentistry\/dopamine-antagonist<\/em><\/a><em><\/em><\/li>\n<li><em>&#8220;Pharmacology Guide: In vitro<br>\npharmacology: concentration-response curves.&#8221; GlaxoWellcome. Retrieved on<br>\nDecember 6, 2007.<\/em><\/li>\n<li><em>Physiology of Behavior, Neil R.<br>\nCarlson, 2001<\/em><\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Table of Contents Boost Your Brain with Mind Lab Pro Benefits Types Chemical AntagonistsPhysiological AntagonistPharmacological AntagonistReversible or competitive antagonistIrreversible or &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Antagonists\" class=\"read-more button\" href=\"https:\/\/human-memory.net\/antagonists\/#more-658\" aria-label=\"Read more about Antagonists\">Read more<\/a><\/p>\n","protected":false},"author":12,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_generate-full-width-content":"","kt_blocks_editor_width":"","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-658","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/posts\/658","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/comments?post=658"}],"version-history":[{"count":1,"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/posts\/658\/revisions"}],"predecessor-version":[{"id":3929,"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/posts\/658\/revisions\/3929"}],"wp:attachment":[{"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/media?parent=658"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/categories?post=658"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/human-memory.net\/wp-json\/wp\/v2\/tags?post=658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}