{"id":149,"date":"2019-04-24T12:52:38","date_gmt":"2019-04-24T12:52:38","guid":{"rendered":"https:\/\/sepia2.unil.ch\/pharmacology\/?page_id=149"},"modified":"2020-09-04T03:47:57","modified_gmt":"2020-09-04T03:47:57","slug":"single-compartment-model","status":"publish","type":"page","link":"https:\/\/sepia2.unil.ch\/pharmacology\/profiles\/single-compartment-model\/","title":{"rendered":"Single-compartment Model"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"> &#8220;Model describing drug absorption, distribution and elimination from a unique compartment in the body&#8221; <\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Description<\/h3>\n\n\n\n<p>In single-compartment modeling, the drug is \nconsidered to be distributed instantaneously into a unique compartment \nin the body. This compartment is characterized by a distribution volume.\n The drug input into this volume depends on the dosage regimen. The drug\n output from this volume is characterized by an elimination constant \nrate. Several dosage regimens are considered here:<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>An <a href=\"\/pharmacology\/intravenous-bolus\">intravenous bolus injection<\/a>:\n the input is equal to the dose at the time point 0 and becomes equal to\n 0 thereafter. The concentration at time 0, C(0), corresponds to the \ndose divided by the volume. Subsequently, the concentration decreases in\n an exponential manner.<\/li><li><a href=\"\/pharmacology\/intravenous-infusion\">Intravenous infusion<\/a>:\n the drug input is constant and equal to the rate of infusion of the \ndrug. Therefore, the amount of drug in the volume progressively \nincreases until equilibrium is reached when the drug input rate equals \nthe output rate. In other words, equilibrium is reached when the rate of\n elimination (which increases with the amount of drug in the volume) \ncompensates for the rate of infusion.<\/li><li><a href=\"\/pharmacology\/extravascular-administration\">Extravascular dose<\/a>:\n we only consider the case when the input rate follows linear kinetics: \nthe rate of absorption may be characterized by an absorption rate \nconstant and is proportional to the amount of drug available for \nabsorption. The concentration at any time point results from the drug \ninput into the volume minus the output which both vary with time \ndepending on the amount of drug available for absorption and for \nelimination.<\/li><\/ol>\n\n\n\n<figure class=\"wp-block-video aligncenter\"><video height=\"336\" style=\"aspect-ratio: 334 \/ 336;\" width=\"334\" autoplay controls loop src=\"https:\/\/sepia2.unil.ch\/pharmacology\/wp-content\/uploads\/2019\/06\/singlecompartmentmodel_Trim.mp4\"><\/video><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Clinical implications<\/h3>\n\n\n\n<p>This model is an easy way of representing the \ndrug outcome in the body when the drug is rapidly distributed within the\n volume of distribution. Such a representation allows predictions of \nplasma drug concentration profiles in different conditions and a more \naccurate estimation of the initial dosage regimen to be given to a \npatient.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Assessment<\/h3>\n\n\n\n<p>Single compartment representation<\/p>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"aligncenter\"><img loading=\"lazy\" decoding=\"async\" width=\"350\" height=\"80\" src=\"https:\/\/sepia2.unil.ch\/pharmacology\/wp-content\/uploads\/2020\/09\/eq_single_compartment1.gif\" alt=\"\" class=\"wp-image-1325\"\/><\/figure><\/div>\n\n\n\n<p>Differential equation describing this single compartmental model:\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\">$${dA \\over dt} = \\text{Input } &#8211; (k10 * A)$$<\/p><p class=\"formula\"><\/div>\n\n\n\n<p>Considering that :\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\">$$CL = k10 * V$$<\/p><p class=\"formula\"><\/div>\n\n\n\n<p>The following equation may apply to the model:\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\">$${dC \\over dt} = {\\text{Input }-(CL*C) \\over V}$$<\/p><p class=\"formula\"><\/div>\n\n\n\n<p>A = amount of drug\n<\/p>\n\n\n\n<p>k10 = Transfer constant rate from the compartment (1) to the outside of the body (0) \n<\/p>\n\n\n\n<p>V = volume of the compartment\n<\/p>\n\n\n\n<p>CL = <a href=\"\/pharmacology\/clearance\">clearance<\/a>\n<\/p>\n\n\n\n<p>C = concentration in the volume<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&#8220;Model describing drug absorption, distribution and elimination from a unique compartment in the body&#8221; Description In single-compartment modeling, the drug is considered to be distributed instantaneously into a unique compartment in the body. This compartment is characterized by a distribution volume. The drug input into this volume depends on the dosage regimen. The drug output &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/sepia2.unil.ch\/pharmacology\/profiles\/single-compartment-model\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Single-compartment Model&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":8,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-149","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/149","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=149"}],"version-history":[{"count":13,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/149\/revisions"}],"predecessor-version":[{"id":1326,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/149\/revisions\/1326"}],"up":[{"embeddable":true,"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/pages\/8"}],"wp:attachment":[{"href":"https:\/\/sepia2.unil.ch\/pharmacology\/wp-json\/wp\/v2\/media?parent=149"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}