{"id":1736,"date":"2022-08-12T09:18:00","date_gmt":"2022-08-12T03:48:00","guid":{"rendered":"https:\/\/chiralpedia.com\/blog\/?p=1736"},"modified":"2024-07-05T10:49:24","modified_gmt":"2024-07-05T05:19:24","slug":"levocetirizine","status":"publish","type":"post","link":"https:\/\/chiralpedia.com\/blog\/levocetirizine\/","title":{"rendered":"Levocetirizine"},"content":{"rendered":"\n<p><\/p>\n\n\n\n<p>Levocetirizine, is chiral switch cetirizine, employed  for allergies. It is a third generation, non-sedating, selective\u00a0histamine\u00a0H1 receptor antagonist, with antihistamine, anti-inflammatory and potential anti-angiogenic activities. Levocetirizine is\u00a0used to relieve the symptoms of hay fever and hives of the skin. It is an antihistamine that works by preventing the effects of a substance called histamine, which is produced by the body.\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"256\" src=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2022\/08\/levocetrizine-3.png\" alt=\"\" class=\"wp-image-1758\" srcset=\"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2022\/08\/levocetrizine-3.png 500w, https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2022\/08\/levocetrizine-3-300x154.png 300w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/figure>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-medium-font-size\"><strong>Chirality and Biological activity<\/strong><\/p>\n\n\n\n<p>Cetirizine carries one stereogenic carbon (indicted by an red arrow mark) and hence exists as a racemic mixture of levocetirizine [(R)-enantiomer] and dextrocetirizine [(S)-enantiomer]. (S)-enantiomer is essentially inactive.<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-medium-font-size\"><strong>Claim for the chiral switch<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&nbsp;&nbsp;R-enantiomer is 2-4 x more potent than the racemate<\/li>\n\n\n\n<li>&nbsp;&nbsp;Decreased side effects<\/li>\n<\/ul>\n\n\n\n<p>Note: There are contradictory observations on this chiral switch. Some studies based on <em>available clinical evidence coupled with the cost differential, criticize that there is no rationale for prescribing levocetirizine in place of cetirizine.<\/em> Further, state that the therapeutic advantages of single enantiomer drugs levocetirizine over their racemate have been disappointing. [Source:[<a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/24066264\/\">https:\/\/pubmed.ncbi.nlm.nih.gov\/24066264\/<\/a>].<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-medium-font-size\"><strong>Nomenclature<\/strong><\/p>\n\n\n\n<p>2-[2-[4-[(<em>R<\/em>)-(4-chlorophenyl)-phenylmethyl]piperazin-1-yl]ethoxy]acetic acid                                                                                                (R)-2-[2-[4-[(4-chlorophenyl)-phenylmethyl]piperazin-1-yl]ethoxy]acetic acid<\/p>\n\n\n\n<p>2-[2-[4-[(<em>R<\/em>)-(4-chlorophenyl)-phenylmethyl]piperazin-1-yl]ethoxy]acetic acid<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-medium-font-size\"><strong>Exercise<\/strong><\/p>\n\n\n\n<p>Understand the nomenclature of levocetirizine and the stereochemical descriptors employed<\/p>\n\n\n\n<p class=\"has-ast-global-color-0-color has-text-color has-medium-font-size\"><strong>Reference<\/strong><\/p>\n\n\n\n<p>Harkishan Singh and V.K. Kapoor.<em><strong>&nbsp;<\/strong>Medicinal chemistry and pharmaceutical chemistry,<\/em>&nbsp;Vallabh Prakashan, New Delhi, Page 277, 2012.<\/p>\n\n\n\n<p>Kathryn Blake &nbsp;and&nbsp;<a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/?term=Raissy%20H%5BAuthor%5D\">Hengameh Raissy<\/a>. Chiral Switch Drugs for Asthma and Allergies: True Benefit or Marketing Hype, &nbsp;<a href=\"https:\/\/www.ncbi.nlm.nih.gov\/pmc\/articles\/PMC3777548\/\">Pediatr Allergy Immunol Pulmonol.<\/a>, 26(3), 157\u2013160, 2013.<\/p>\n\n\n\n<p>Chiral switch. Wikipedia, Wikipedia Foundation, 12\/08\/2022. &nbsp;<a href=\"https:\/\/en.wikipedia.org\/wiki\/Chiral_switch\">https:\/\/en.wikipedia.org\/wiki\/Chiral_switch<\/a>&nbsp;and references therein<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Levocetirizine, is chiral switch cetirizine, employed for allergies. It is a third generation, non-sedating, selective\u00a0histamine\u00a0H1 receptor antagonist, with antihistamine, anti-inflammatory and potential anti-angiogenic activities. Levocetirizine is\u00a0used to relieve the symptoms of hay fever and hives of the skin. It is an antihistamine that works by preventing the effects of a substance called histamine, which is produced by the body.\u00a0 Chirality and Biological activity Cetirizine carries one stereogenic carbon (indicted by an red arrow mark) and &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"https:\/\/chiralpedia.com\/blog\/levocetirizine\/\"> <span class=\"screen-reader-text\">Levocetirizine<\/span> Read More &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":1742,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-sidebar-layout":"","site-content-layout":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","footnotes":""},"categories":[43],"tags":[23,22,67,65],"ppma_author":[93],"class_list":["post-1736","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-chirality","tag-chiral_drugs","tag-chirality","tag-chiralpedia","tag-cmotw"],"authors":[{"term_id":93,"user_id":1,"is_guest":0,"slug":"chiralusrblg","display_name":"Valliappan Kannappan","avatar_url":{"url":"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2024\/09\/vk.jpg","url2x":"https:\/\/chiralpedia.com\/blog\/wp-content\/uploads\/2024\/09\/vk.jpg"},"first_name":"","last_name":"","user_url":"https:\/\/chiralpedia.com\/blog\/","job_title":"Founder, chiralpedia.com","description":""}],"_links":{"self":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts\/1736","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/comments?post=1736"}],"version-history":[{"count":19,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts\/1736\/revisions"}],"predecessor-version":[{"id":2409,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/posts\/1736\/revisions\/2409"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/media\/1742"}],"wp:attachment":[{"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/media?parent=1736"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/categories?post=1736"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/tags?post=1736"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/chiralpedia.com\/blog\/wp-json\/wp\/v2\/ppma_author?post=1736"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}