{"id":111,"date":"2019-04-24T12:39:34","date_gmt":"2019-04-24T12:39:34","guid":{"rendered":"https:\/\/sepia2.unil.ch\/pharmacology\/?page_id=111"},"modified":"2020-09-04T03:22:44","modified_gmt":"2020-09-04T03:22:44","slug":"areaunderthecurve","status":"publish","type":"page","link":"https:\/\/sepia2.unil.ch\/pharmacology\/parameters\/areaunderthecurve\/","title":{"rendered":"Area under the Curve"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">&#8220;Integral of the plasma drug concentration-time curve&#8221; <\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Description<\/h3>\n\n\n\n<p>The area under the plasma drug concentration-time\n curve (AUC) reflects the actual body exposure to drug after \nadministration of a dose of the drug and is expressed in mg*h\/L.\n<\/p>\n\n\n\n<p>This area under the curve is dependant on the rate \nof elimination of the drug from the body and the dose administered. The \ntotal amount of drug eliminated by the body may be assessed by adding up\n or integrating the amounts eliminated in each time interval, from time \nzero (time of the administration of the drug) to infinite time. This \ntotal amount corresponds to the fraction of the dose administered that \nreaches the systemic circulation. \n<\/p>\n\n\n\n<p>The AUC is directly proportional to the dose when the drug follows linear kinetics. The AUC is inversely proportional to the <a href=\"\/pharmacology\/clearance\">clearance<\/a>  of the drug. That is, the higher the clearance, the less time the drug  spends in the systemic circulation and the faster the decline in the  plasma drug concentration. Therefore, in such situations, the body  exposure to the drug and the area under the concentration-time curve are  smaller.<\/p>\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<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/sepia2.unil.ch\/pharmacology\/wp-content\/uploads\/2019\/06\/eq_auc3_01.gif\" alt=\"\" class=\"wp-image-399\"\/><\/figure>\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-image\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/sepia2.unil.ch\/pharmacology\/wp-content\/uploads\/2019\/06\/eq_auc4_01.gif\" alt=\"\" class=\"wp-image-400\"\/><\/figure>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-blocks-latex-block-latex\"><script type=\"text\/x-mathjax-config\">   MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\\\(','\\\\)']]}}); <\/script> <p class=\"formula\">$$AUC = \\color{cyan}{AUC0}-\\color{cyan}2 + \\color{pink}{AUC2}-\\color{pink}4+\\color{purple}{AUC4}-\\color{purple}{6}+\\\\\\color{yellow}{AUC6}-\\color{yellow}{8}+\\color{green}{AUC8}-\\color{green}{10}+\\color{HotPink}{AUC10}-\\color{HotPink}{12}+\\\\\\color{RoyalBlue}{AUC last}-\\color{RoyalBlue}{infinity}$$<\/p><p class=\"formula\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical implications<\/h3>\n\n\n\n<p>During clinical trials, the patient&#8217;s plasma drug  concentration-time profile can be drawn by measuring the plasma  concentration at several time points. The AUC can then be estimated.  Knowing the <a href=\"\/pharmacology\/bioavailability\">bioavailability<\/a> and the dose, the <a href=\"\/pharmacology\/clearance\">clearance<\/a>  of the drug may be calculated by dividing the dose absorbed by the AUC.  The clearance calculated is relatively independent on the shape of the  concentration-time profile. This method gives precious information on  the pharmacokinetic behavior of a drug on trial. It can also be used to  study a change in the clearance of a drug in specific clinical  conditions, such as <a href=\"\/pharmacology\/disease-and-variability\">disease<\/a> or <a href=\"\/pharmacology\/concomitant-drugs\">concomitant drug administration<\/a>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Related terms<\/h3>\n\n\n\n<p>Apparent clearance (CL&#8217;): In some pharmacokinetic trials, the <a href=\"\/pharmacology\/bioavailability\">bioavailability<\/a>\n of the studied drug is not known. The apparent clearance, resulting \nfrom the dose divided by the AUC, reflects the drug&#8217;s clearance that \ndoes not take into account the&nbsp;bioavailability of the drug. \n<\/p>\n\n\n\n<p><a href=\"\/pharmacology\/bioavailability\">Relative bioavailability<\/a><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Assessment<\/h3>\n\n\n\n<div class=\"wp-block-blocks-latex-block-latex\"><script type=\"text\/x-mathjax-config\">   MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\\\(','\\\\)']]}}); <\/script> <p class=\"formula\">$$AUC = {F * D \\over CL}$$<\/p><p class=\"formula\"><\/div>\n\n\n\n<p>After an <a href=\"\/pharmacology\/intravenous-bolus\">iv bolus injection<\/a>, the AUC can be calculated by the following equation:\n<\/p>\n\n\n\n<div class=\"wp-block-blocks-latex-block-latex\"><script type=\"text\/x-mathjax-config\">   MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\\\(','\\\\)']]}}); <\/script> <p class=\"formula\">$$AUC = { C(0) \\over \\lambda} $$<\/p><p class=\"formula\"><\/div>\n\n\n\n<p>Trapezoidal rule: It consists in dividing the plasma\n concentration-time profile into several trapezoids and calculating the \nAUC by adding the area of these trapezoids.\n<\/p>\n\n\n\n<p><strong>AUC<\/strong> = Area under the concentration-time curve <\/p>\n\n\n\n<p><strong>F<\/strong> = <a href=\"\/pharmacology\/bioavailability\">bioavailability<\/a> <\/p>\n\n\n\n<p><strong>D<\/strong> = dose <\/p>\n\n\n\n<p><strong>CL<\/strong> = <a href=\"\/pharmacology\/clearance\">clearance<\/a> <\/p>\n\n\n\n<p><strong>C(0)<\/strong> = extrapolated plasma concentration at time&nbsp;0&nbsp; <\/p>\n\n\n\n<p> <strong>\u03bb<\/strong>  = <a href=\"\/pharmacology\/halflife\">elimination rate constant<\/a>\u00a0= CL\/Vd<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&#8220;Integral of the plasma drug concentration-time curve&#8221; Description The area under the plasma drug concentration-time curve (AUC) reflects the actual body exposure to drug after administration of a dose of the drug and is expressed in mg*h\/L. This area under the curve is dependant on the rate of elimination of the drug from the body &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/sepia2.unil.ch\/pharmacology\/parameters\/areaunderthecurve\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Area under the Curve&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":7,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-111","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/111","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=111"}],"version-history":[{"count":38,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/111\/revisions"}],"predecessor-version":[{"id":1303,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/111\/revisions\/1303"}],"up":[{"embeddable":true,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/7"}],"wp:attachment":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/media?parent=111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}