{"id":88,"date":"2019-04-24T12:15:55","date_gmt":"2019-04-24T12:15:55","guid":{"rendered":"https:\/\/sepia2.unil.ch\/pharmacology\/?page_id=88"},"modified":"2019-04-26T14:27:36","modified_gmt":"2019-04-26T14:27:36","slug":"renal-excretion","status":"publish","type":"page","link":"https:\/\/sepia2.unil.ch\/pharmacology\/mechanisms\/renal-excretion\/","title":{"rendered":"Renal Excretion"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"> &#8220;Irreversible transfer of drug or drug metabolites from the plasma into the urine&#8221; <\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Description<\/h3>\n\n\n\n<div class=\"wp-block-columns has-2-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p> Drug or drug metabolites must be hydrosoluble to be  excreted in the urine. Factors that influence renal excretion include  plasma drug concentration, plasma protein binding and renal function. <\/p>\n\n\n\n<p>Drugs are transferred from the plasma into the urine by:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>Glomerular filtration: Unbound drug molecules of less than 20&#8217;000 Da are filtered through the glomerulus with the primary urine.<\/li><li>Active  tubular secretion: This mechanism is predominant in the proximal  tubule. Several transportors are responsible for the tubular secretion  of drugs: the P-glycoproteins (PGps), the multidrug  resistance-associated proteins (MRPs), the organic anion transportors  (OATs), the oragnic cation transportors (OCTs), etc. These transporters  are not highly specific and may become saturated at high drug  concentrations.<\/li><\/ol>\n\n\n\n<p><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-video\"><video height=\"346\" style=\"aspect-ratio: 346 \/ 346;\" width=\"346\" controls src=\"https:\/\/sepia2.unil.ch\/pharmacology\/wp-content\/uploads\/2019\/04\/renalexcretion_Trim.mp4\"><\/video><\/figure>\n<\/div>\n<\/div>\n\n\n\n<p>  Drugs may be reabsorbed from the tubular lumen by passive diffusion. The  extent of reabsorption depends on the lipophilic properties of the  drug, on urine flow, urine pH and chelating agents. Concentrated urine  favors reabsorption. Depending on the urine pH, a weak acid or base can  be more or less ionised in the urine and therefore for more or less  reabsorbed (urine ion trapping). Active reabsorption occurs mainly for  endogenous products such as vitamins, glucose and amino acids and  similar substances. <\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical implications<\/h3>\n\n\n\n<p>Changes in renal function affect filtration, \nsecretion and tubular reabsorption. Impairment of renal function, due to\n disease, leads to decrease in renal drug clearance. In such situations \nthe dosage regimen must be adapted, specially for drugs with a low <a href=\"\/pharmacology\/hepaticclearance\">extrarenal fraction<\/a>\n (Qo). Reduced clearance can also result from competition between drugs \nor endogenous substances for the tubular secretion transporter sites \n(renal drug interactions).\n<\/p>\n\n\n\n<p>Following intoxication, forced diuresis and urine pH\n control can be useful to increase the renal excretion of certain drugs \nand toxics.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Related terms<\/h3>\n\n\n\n<p>Ion trapping: drugs in an unionised form diffuse \nacross cellular membranes. If there is a difference in pH between two \ncompartments separated by a membrane, weak acids will accumulate in a \nbasic compartment and weak bases will accumulate in an acidic \ncompartment.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&#8220;Irreversible transfer of drug or drug metabolites from the plasma into the urine&#8221; Description Drug or drug metabolites must be hydrosoluble to be excreted in the urine. Factors that influence renal excretion include plasma drug concentration, plasma protein binding and renal function. Drugs are transferred from the plasma into the urine by: Glomerular filtration: Unbound &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/sepia2.unil.ch\/pharmacology\/mechanisms\/renal-excretion\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Renal Excretion&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":11,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-88","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/88","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/comments?post=88"}],"version-history":[{"count":2,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/88\/revisions"}],"predecessor-version":[{"id":313,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/88\/revisions\/313"}],"up":[{"embeddable":true,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/11"}],"wp:attachment":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/media?parent=88"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}