{"id":30,"date":"2019-09-18T15:59:22","date_gmt":"2019-09-18T19:59:22","guid":{"rendered":"https:\/\/opentextbc.ca\/nursingpharmacology\/chapter\/1-3-absorption\/"},"modified":"2023-03-02T15:49:18","modified_gmt":"2023-03-02T20:49:18","slug":"1-3-absorption","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/nursingpharmacology\/chapter\/1-3-absorption\/","title":{"raw":"1.3 Pharmacokinetics \u2013 Absorption","rendered":"1.3 Pharmacokinetics \u2013 Absorption"},"content":{"raw":"The first stage of pharmacokinetics is known as <strong>[pb_glossary id=\"560\"]absorption[\/pb_glossary]<\/strong>. Absorption occurs after drugs enter the body and travel from the site of administration into the body's circulation. Medications can enter the body through various routes of administration. Common routes to administer medications include the following examples:\r\n<ul>\r\n \t<li>oral (swallowing an aspirin tablet)<\/li>\r\n \t<li>sublingual (dissolved under the tongue)<\/li>\r\n \t<li>enteral (administering to the GI tract such as via a nasogastric tube)<\/li>\r\n \t<li>rectal (administering a Tylenol suppository)<\/li>\r\n \t<li>inhalation (breathing in medication from an inhaler)<\/li>\r\n \t<li>intramuscular (getting a flu shot in the deltoid muscle)<\/li>\r\n \t<li>subcutaneous (injecting insulin into the fat tissue beneath the skin)<\/li>\r\n \t<li>transdermal (wearing a nicotine patch)<\/li>\r\n<\/ul>\r\nWhen a medication is administered orally or enterally, it faces its biggest hurdle during absorption in the gastrointestinal (GI) tract. Medications made of protein, that are swallowed or otherwise absorbed in the GI tract, may quickly be deactivated by enzymes as they pass through the stomach and duodenum. If the drug does get into the blood from the intestines, part of it will be broken down by liver enzymes, known as the [pb_glossary id=\"799\"]first-pass effect[\/pb_glossary], and some of it will escape to the general circulation to either become protein-bound (inactive) or stay free (and create an action at a receptor site). These metabolic effects are further described in the \"Metabolism\" section later in this chapter. Providers who prescribe medications, as well as nurses, understand that several doses of an oral medication may be needed before enough free drug stays active in the circulation to exert the desired effect.\r\n\r\nA workaround to the first-pass effect is to administer the medication using alternate routes such as dermal, nasal,\u00a0 inhalation, injection, or intravenous. Alternative routes of medication administration bypass the first-pass effect by entering the bloodstream directly or via absorption through the skin or lungs. Medications that are administered directly into the bloodstream (referred to as intravenous medications) do not undergo absorption and are fully available for distribution to tissues within the body.\r\n\r\nAlternative routes of medication have other potential problems to consider. For example, injections are often painful and cause a break in the skin, an important barrier to infection. They can also be costly and difficult to administer daily, cause localized side effects, or contribute to unpredictable fluctuations in medication blood levels.\r\n\r\n[caption id=\"attachment_26\" align=\"alignright\" width=\"234\"]<img class=\"wp-image-26\" title=\"&quot;Applying transdermal patch.jpg&quot; by British Columbia Institute of Technology (BCIT) is licensed under CC BY 4.0\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-268x300.png\" alt=\"Photo of transdermal patch being applied to an arm\" width=\"234\" height=\"262\" \/> Figure 1.3a Applying Transdermal Patch[\/caption]\r\n\r\nTransdermal application of medication is an alternate route that has the primary benefit of slow, steady drug delivery directly to the bloodstream\u2014without passing through the liver first.\u00a0 (See Figure 1.3a[footnote]\"<a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Applying_transdermal_patch.jpg\" rel=\"noopener noreferrer\">Applying transdermal patch.jpg<\/a>\" by <a href=\"https:\/\/www.bcit.ca\/\" rel=\"noopener noreferrer\">British Columbia Institute of Technology (BCIT)<\/a> is licensed under <a class=\"internal\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/deed.ast\" rel=\"noopener noreferrer\">CC BY 4.0<\/a>[\/footnote] for an image of applying a transdermal patch.) Drugs delivered transdermally enter the blood via a meshwork of small arteries, veins, and capillaries in the skin. This makes the transdermal route of drug delivery particularly useful when medication must be administered over a long period of time to control symptoms. For example, transdermal application of fentanyl, a pain medication, can provide effective pain management over a long period of time; the scopolamine patch can control motion sickness over the duration of a cruise ship vacation, and the nitroglycerin patch is used to control chronic chest pain. Despite their advantages, skin patches have a significant drawback in that only very small drug molecules can enter the body through the skin, making this application route not applicable for all types of medications.\r\n\r\nInhaling drugs through the nose or mouth is another alternative route for rapid medication delivery that bypasses the liver (see <a href=\"#13b\">Figure 1.3b<\/a>).\u00a0Metered-dose inhalers have been a mainstay of asthma therapy for several years, and nasal steroid medications are often prescribed for allergy and sinus problems.\r\n<h1>Lifespan Considerations<\/h1>\r\n<strong>Neonate &amp; Pediatric:<\/strong> Gastric absorption in neonatal and pediatric clients varies from that of their adult counterparts. In neonate and pediatric clients, the acid-producing cells of the stomach are immature until around the age of one to two years. Additionally, gastric emptying may be decreased because of slowed or irregular peristalsis (forward bowel movement). The liver of a neonatal or pediatric client continues to mature, experiencing a decrease in first-pass elimination, resulting in higher drug levels in the bloodstream.[footnote]Fernandez, E., Perez, R., Hernandez, A., Tejada, P., Arteta, M., &amp; Ramos, J. T. (2011). Factors and mechanisms for pharmacokinetic differences between pediatric population and adults. Pharmaceutics, 3(1), 53\u201372. <a class=\"internal\" href=\"https:\/\/doi.org\/10.3390\/pharmaceutics3010053\" rel=\"noopener noreferrer\">https:\/\/doi.org\/10.3390\/pharmaceutics3010053<\/a>[\/footnote]\r\n\r\n<strong>Older Adult:<\/strong>\u00a0 As a natural result of aging, older adults will experience decreased blood flow to tissues within the GI tract. In addition, there may be changes in the gastric (stomach) pH that may alter the absorption of certain medications. Older adult clients may also experience variations in available plasma proteins, which can impact drug levels of medications that are highly protein-bound. Consideration must also be given to the use of subcutaneous and intramuscular injections in older clients experiencing decreased cardiac output. Decreased drug absorption of medications can occur when peripheral circulation is decreased. Finally, as adults age, they often have less body fat, resulting in decreased absorption of medication from transdermal patches that require adequate subcutaneous fat stores for proper absorption.[footnote]Fernandez, E., Perez, R., Hernandez, A., Tejada, P., Arteta, M., &amp; Ramos, J. T. (2011). Factors and mechanisms for pharmacokinetic differences between pediatric population and adults. Pharmaceutics, 3(1), 53\u201372. <a class=\"internal\" href=\"https:\/\/doi.org\/10.3390\/pharmaceutics3010053\" rel=\"noopener noreferrer\">https:\/\/doi.org\/10.3390\/pharmaceutics3010053<\/a>[\/footnote]Table 1 summarizes route options that a nurse should consider when administering medication.\r\n<table class=\"grid\" style=\"border-collapse: collapse; width: 100%;\" border=\"0\"><caption>Table 1.3: Medication Route Considerations\u00a0<\/caption>\r\n<tbody>\r\n<tr>\r\n<th class=\"shaded\" style=\"width: 47.3799%;\" scope=\"col\">Medication Route<\/th>\r\n<th class=\"shaded\" style=\"width: 52.5109%;\" scope=\"col\">Considerations<\/th>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"width: 47.3799%;\" scope=\"row\">Oral (PO), Sublingual (SL) or Enteral (NGT, GT, OGT) Ingestion\r\n\r\n<img src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2022\/05\/Adminstering_oral_medication-scaled-1.jpeg\" alt=\"a nurse demonstrates how to adminster oral medication on a medical mannequin\" width=\"300\" height=\"216\" \/><\/td>\r\n<td style=\"width: 52.5109%;\">\r\n<ul>\r\n \t<li>Oral route is a convenient route for administration of solid as well as liquid formulations.<\/li>\r\n \t<li>Additional variables that may influence the rate and extent of absorption include enteric coating or extended-release formulations, acidity of gastric contents, gastric emptying rate, dietary contents, and presence of other drugs.<\/li>\r\n \t<li>First-pass effect: Blood containing the absorbed drug passes through the liver, which can deactivate a substantial amount of the drug and decrease its bioavailability (the percentage of dose that reaches the systemic circulation).<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"width: 47.3799%;\" scope=\"row\">Parenteral Injection (SC, IM, IV)\r\n\r\n<img src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2022\/05\/Vaccination-ChristianEmmer-CC-by-nc-4.0.jpeg\" alt=\"a nurse about to inject the arm of a patient with a small needle\" width=\"300\" height=\"167\" \/><\/td>\r\n<td style=\"width: 52.5109%;\">\r\n<ul>\r\n \t<li>Subcutaneous and intramuscular administration:\u00a0 Injections can be difficult for clients to self-administer at home or to administer on a daily basis.\u00a0 They can be costly and painful. Injections also cause a break in skin that is an important barrier to infection, and can cause fluctuation in drug levels and localized side effects to skin.<\/li>\r\n \t<li>Intravenous (IV): IV drugs are fully available to tissues after administration into the bloodstream, offering complete bioavailability and an immediate effect.\u00a0 However, this route requires intravenous access that can be painful to the client and also increases risk of infection.\u00a0 Medications must be administered in sterile fashion, and if two products are administered simultaneously, their compatibility must be verified.\u00a0 There is also an increased risk of toxicity.<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"width: 47.3799%;\" scope=\"row\"><a id=\"13b\"><\/a>Pulmonary Inhalation\r\n<div>\r\n<dl id=\"attachment_928\">\r\n \t<dt>[caption id=\"\" align=\"alignnone\" width=\"300\"]<img src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2022\/05\/29251369035_9ab3f4d858_b.jpeg\" alt=\"person using a metered dose asthma inhaler\" width=\"300\" height=\"249\" \/> Figure 1.3b \u201cAdult Using Asthma Inhaler\u201d by NIAID[footnote]\u201cAdult Using Asthma Inhaler\u201d by NIAID is licensed under CC BY 2.0[\/footnote][\/caption]<\/dt>\r\n<\/dl>\r\n<\/div><\/td>\r\n<td style=\"width: 52.5109%;\">\r\n<ul>\r\n \t<li>Inhalation allows for rapid absorption of drugs in gaseous, vaporized or aerosol form.<\/li>\r\n \t<li>Absorption of particulates\/aerosols depends on particle\/droplet size, which influences depth of entry through the pulmonary tree to reach the alveoli. The ability of the client to create successful inhalation, especially in the presence of bronchospasm, may also influence depth of entry in the pulmonary tree.<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<tr style=\"height: 243px;\">\r\n<td style=\"width: 47.3799%;\" scope=\"row\">Topical and Transdermal Application\r\n\r\n<img title=\"&quot;Applying transdermal patch.jpg&quot; by British Columbia Institute of Technology (BCIT) is licensed under CC BY 4.0\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-268x300.png\" alt=\"Photo of transdermal patch being applied to an arm\" width=\"160\" height=\"179\" \/><\/td>\r\n<td style=\"width: 52.5109%;\">\r\n<ul>\r\n \t<li>Topical creams, lotions, and ointments are generally used for local effect; transdermal patch formulations are used for systemic effect.<\/li>\r\n \t<li>Absorption through the buccal or sublingual membranes may be rapid.<\/li>\r\n \t<li>Absorption through skin is generally slower but produces steady, long-term effect that avoids the first-pass effect.\u00a0 However, absorption of medication is affected by blood flow to the skin.<\/li>\r\n<\/ul>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<div class=\"textbox\">\r\n<h3 class=\"star\">\u00a0Interactive Activity<\/h3>\r\n[h5p id=\"1\"]\r\n\r\n<\/div>\r\n<h3>Attributions<\/h3>\r\n<ul>\r\n \t<li>\"Table 1.3: Medication Route Considerations\" was adapted from Chapter 1.3 Pharmacokinetics in <a href=\"https:\/\/med.libretexts.org\/Bookshelves\/Pharmacology_and_Neuroscience\/Book%3A_Principles_of_Pharmacology_(Rosow_Standaert_and_Strichartz)\"><em>Principles of Pharmacology<\/em><\/a> by Carl Rosow, David Standaert, and Gary Strichartz, which is licenced under a <a class=\"internal\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\">CC BY-NC-SA 4.0 licence<\/a>. Adapted by Amanda Egert, Kimberly Lee, and Manu Gill.<\/li>\r\n<\/ul>","rendered":"<p>The first stage of pharmacokinetics is known as <strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_30_560\">absorption<\/a><\/strong>. Absorption occurs after drugs enter the body and travel from the site of administration into the body&#8217;s circulation. Medications can enter the body through various routes of administration. Common routes to administer medications include the following examples:<\/p>\n<ul>\n<li>oral (swallowing an aspirin tablet)<\/li>\n<li>sublingual (dissolved under the tongue)<\/li>\n<li>enteral (administering to the GI tract such as via a nasogastric tube)<\/li>\n<li>rectal (administering a Tylenol suppository)<\/li>\n<li>inhalation (breathing in medication from an inhaler)<\/li>\n<li>intramuscular (getting a flu shot in the deltoid muscle)<\/li>\n<li>subcutaneous (injecting insulin into the fat tissue beneath the skin)<\/li>\n<li>transdermal (wearing a nicotine patch)<\/li>\n<\/ul>\n<p>When a medication is administered orally or enterally, it faces its biggest hurdle during absorption in the gastrointestinal (GI) tract. Medications made of protein, that are swallowed or otherwise absorbed in the GI tract, may quickly be deactivated by enzymes as they pass through the stomach and duodenum. If the drug does get into the blood from the intestines, part of it will be broken down by liver enzymes, known as the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_30_799\">first-pass effect<\/a>, and some of it will escape to the general circulation to either become protein-bound (inactive) or stay free (and create an action at a receptor site). These metabolic effects are further described in the &#8220;Metabolism&#8221; section later in this chapter. Providers who prescribe medications, as well as nurses, understand that several doses of an oral medication may be needed before enough free drug stays active in the circulation to exert the desired effect.<\/p>\n<p>A workaround to the first-pass effect is to administer the medication using alternate routes such as dermal, nasal,\u00a0 inhalation, injection, or intravenous. Alternative routes of medication administration bypass the first-pass effect by entering the bloodstream directly or via absorption through the skin or lungs. Medications that are administered directly into the bloodstream (referred to as intravenous medications) do not undergo absorption and are fully available for distribution to tissues within the body.<\/p>\n<p>Alternative routes of medication have other potential problems to consider. For example, injections are often painful and cause a break in the skin, an important barrier to infection. They can also be costly and difficult to administer daily, cause localized side effects, or contribute to unpredictable fluctuations in medication blood levels.<\/p>\n<figure id=\"attachment_26\" aria-describedby=\"caption-attachment-26\" style=\"width: 234px\" class=\"wp-caption alignright\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-26\" title=\"&quot;Applying transdermal patch.jpg&quot; by British Columbia Institute of Technology (BCIT) is licensed under CC BY 4.0\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-268x300.png\" alt=\"Photo of transdermal patch being applied to an arm\" width=\"234\" height=\"262\" srcset=\"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-268x300.png 268w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-915x1024.png 915w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-768x860.png 768w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-1372x1536.png 1372w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-1829x2048.png 1829w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-65x73.png 65w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-225x252.png 225w, https:\/\/opentextbc.ca\/nursingpharmacology\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-350x392.png 350w\" sizes=\"auto, (max-width: 234px) 100vw, 234px\" \/><figcaption id=\"caption-attachment-26\" class=\"wp-caption-text\">Figure 1.3a Applying Transdermal Patch<\/figcaption><\/figure>\n<p>Transdermal application of medication is an alternate route that has the primary benefit of slow, steady drug delivery directly to the bloodstream\u2014without passing through the liver first.\u00a0 (See Figure 1.3a<a class=\"footnote\" title=\"&quot;Applying transdermal patch.jpg&quot; by British Columbia Institute of Technology (BCIT) is licensed under CC BY 4.0\" id=\"return-footnote-30-1\" href=\"#footnote-30-1\" aria-label=\"Footnote 1\"><sup class=\"footnote\">[1]<\/sup><\/a> for an image of applying a transdermal patch.) Drugs delivered transdermally enter the blood via a meshwork of small arteries, veins, and capillaries in the skin. This makes the transdermal route of drug delivery particularly useful when medication must be administered over a long period of time to control symptoms. For example, transdermal application of fentanyl, a pain medication, can provide effective pain management over a long period of time; the scopolamine patch can control motion sickness over the duration of a cruise ship vacation, and the nitroglycerin patch is used to control chronic chest pain. Despite their advantages, skin patches have a significant drawback in that only very small drug molecules can enter the body through the skin, making this application route not applicable for all types of medications.<\/p>\n<p>Inhaling drugs through the nose or mouth is another alternative route for rapid medication delivery that bypasses the liver (see <a href=\"#13b\">Figure 1.3b<\/a>).\u00a0Metered-dose inhalers have been a mainstay of asthma therapy for several years, and nasal steroid medications are often prescribed for allergy and sinus problems.<\/p>\n<h1>Lifespan Considerations<\/h1>\n<p><strong>Neonate &amp; Pediatric:<\/strong> Gastric absorption in neonatal and pediatric clients varies from that of their adult counterparts. In neonate and pediatric clients, the acid-producing cells of the stomach are immature until around the age of one to two years. Additionally, gastric emptying may be decreased because of slowed or irregular peristalsis (forward bowel movement). The liver of a neonatal or pediatric client continues to mature, experiencing a decrease in first-pass elimination, resulting in higher drug levels in the bloodstream.<a class=\"footnote\" title=\"Fernandez, E., Perez, R., Hernandez, A., Tejada, P., Arteta, M., &amp; Ramos, J. T. (2011). Factors and mechanisms for pharmacokinetic differences between pediatric population and adults. Pharmaceutics, 3(1), 53\u201372. https:\/\/doi.org\/10.3390\/pharmaceutics3010053\" id=\"return-footnote-30-2\" href=\"#footnote-30-2\" aria-label=\"Footnote 2\"><sup class=\"footnote\">[2]<\/sup><\/a><\/p>\n<p><strong>Older Adult:<\/strong>\u00a0 As a natural result of aging, older adults will experience decreased blood flow to tissues within the GI tract. In addition, there may be changes in the gastric (stomach) pH that may alter the absorption of certain medications. Older adult clients may also experience variations in available plasma proteins, which can impact drug levels of medications that are highly protein-bound. Consideration must also be given to the use of subcutaneous and intramuscular injections in older clients experiencing decreased cardiac output. Decreased drug absorption of medications can occur when peripheral circulation is decreased. Finally, as adults age, they often have less body fat, resulting in decreased absorption of medication from transdermal patches that require adequate subcutaneous fat stores for proper absorption.<a class=\"footnote\" title=\"Fernandez, E., Perez, R., Hernandez, A., Tejada, P., Arteta, M., &amp; Ramos, J. T. (2011). Factors and mechanisms for pharmacokinetic differences between pediatric population and adults. Pharmaceutics, 3(1), 53\u201372. https:\/\/doi.org\/10.3390\/pharmaceutics3010053\" id=\"return-footnote-30-3\" href=\"#footnote-30-3\" aria-label=\"Footnote 3\"><sup class=\"footnote\">[3]<\/sup><\/a>Table 1 summarizes route options that a nurse should consider when administering medication.<\/p>\n<table class=\"grid\" style=\"border-collapse: collapse; width: 100%;\">\n<caption>Table 1.3: Medication Route Considerations\u00a0<\/caption>\n<tbody>\n<tr>\n<th class=\"shaded\" style=\"width: 47.3799%;\" scope=\"col\">Medication Route<\/th>\n<th class=\"shaded\" style=\"width: 52.5109%;\" scope=\"col\">Considerations<\/th>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"width: 47.3799%;\" scope=\"row\">Oral (PO), Sublingual (SL) or Enteral (NGT, GT, OGT) Ingestion<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2022\/05\/Adminstering_oral_medication-scaled-1.jpeg\" alt=\"a nurse demonstrates how to adminster oral medication on a medical mannequin\" width=\"300\" height=\"216\" \/><\/td>\n<td style=\"width: 52.5109%;\">\n<ul>\n<li>Oral route is a convenient route for administration of solid as well as liquid formulations.<\/li>\n<li>Additional variables that may influence the rate and extent of absorption include enteric coating or extended-release formulations, acidity of gastric contents, gastric emptying rate, dietary contents, and presence of other drugs.<\/li>\n<li>First-pass effect: Blood containing the absorbed drug passes through the liver, which can deactivate a substantial amount of the drug and decrease its bioavailability (the percentage of dose that reaches the systemic circulation).<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"width: 47.3799%;\" scope=\"row\">Parenteral Injection (SC, IM, IV)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2022\/05\/Vaccination-ChristianEmmer-CC-by-nc-4.0.jpeg\" alt=\"a nurse about to inject the arm of a patient with a small needle\" width=\"300\" height=\"167\" \/><\/td>\n<td style=\"width: 52.5109%;\">\n<ul>\n<li>Subcutaneous and intramuscular administration:\u00a0 Injections can be difficult for clients to self-administer at home or to administer on a daily basis.\u00a0 They can be costly and painful. Injections also cause a break in skin that is an important barrier to infection, and can cause fluctuation in drug levels and localized side effects to skin.<\/li>\n<li>Intravenous (IV): IV drugs are fully available to tissues after administration into the bloodstream, offering complete bioavailability and an immediate effect.\u00a0 However, this route requires intravenous access that can be painful to the client and also increases risk of infection.\u00a0 Medications must be administered in sterile fashion, and if two products are administered simultaneously, their compatibility must be verified.\u00a0 There is also an increased risk of toxicity.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"width: 47.3799%;\" scope=\"row\"><a id=\"13b\"><\/a>Pulmonary Inhalation<\/p>\n<div>\n<dl id=\"attachment_928\">\n<dt>\n<figure style=\"width: 300px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2022\/05\/29251369035_9ab3f4d858_b.jpeg\" alt=\"person using a metered dose asthma inhaler\" width=\"300\" height=\"249\" \/><figcaption class=\"wp-caption-text\">Figure 1.3b \u201cAdult Using Asthma Inhaler\u201d by NIAID[footnote]\u201cAdult Using Asthma Inhaler\u201d by NIAID is licensed under CC BY 2.0[\/footnote]<\/figcaption><\/figure>\n<\/dt>\n<\/dl>\n<\/div>\n<\/td>\n<td style=\"width: 52.5109%;\">\n<ul>\n<li>Inhalation allows for rapid absorption of drugs in gaseous, vaporized or aerosol form.<\/li>\n<li>Absorption of particulates\/aerosols depends on particle\/droplet size, which influences depth of entry through the pulmonary tree to reach the alveoli. The ability of the client to create successful inhalation, especially in the presence of bronchospasm, may also influence depth of entry in the pulmonary tree.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<tr style=\"height: 243px;\">\n<td style=\"width: 47.3799%;\" scope=\"row\">Topical and Transdermal Application<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" title=\"&quot;Applying transdermal patch.jpg&quot; by British Columbia Institute of Technology (BCIT) is licensed under CC BY 4.0\" src=\"https:\/\/opentextbc.ca\/accessibilitytoolkit\/wp-content\/uploads\/sites\/397\/2019\/09\/image2-268x300.png\" alt=\"Photo of transdermal patch being applied to an arm\" width=\"160\" height=\"179\" \/><\/td>\n<td style=\"width: 52.5109%;\">\n<ul>\n<li>Topical creams, lotions, and ointments are generally used for local effect; transdermal patch formulations are used for systemic effect.<\/li>\n<li>Absorption through the buccal or sublingual membranes may be rapid.<\/li>\n<li>Absorption through skin is generally slower but produces steady, long-term effect that avoids the first-pass effect.\u00a0 However, absorption of medication is affected by blood flow to the skin.<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<div class=\"textbox\">\n<h3 class=\"star\">\u00a0Interactive Activity<\/h3>\n<div id=\"h5p-1\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-1\" class=\"h5p-iframe\" data-content-id=\"1\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Module 1: Absorption Knowledge Check\"><\/iframe><\/div>\n<\/div>\n<\/div>\n<h3>Attributions<\/h3>\n<ul>\n<li>&#8220;Table 1.3: Medication Route Considerations&#8221; was adapted from Chapter 1.3 Pharmacokinetics in <a href=\"https:\/\/med.libretexts.org\/Bookshelves\/Pharmacology_and_Neuroscience\/Book%3A_Principles_of_Pharmacology_(Rosow_Standaert_and_Strichartz)\"><em>Principles of Pharmacology<\/em><\/a> by Carl Rosow, David Standaert, and Gary Strichartz, which is licenced under a <a class=\"internal\" href=\"https:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0\">CC BY-NC-SA 4.0 licence<\/a>. Adapted by Amanda Egert, Kimberly Lee, and Manu Gill.<\/li>\n<\/ul>\n<hr class=\"before-footnotes clear\" \/><div class=\"footnotes\"><ol><li id=\"footnote-30-1\">\"<a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Applying_transdermal_patch.jpg\" rel=\"noopener noreferrer\">Applying transdermal patch.jpg<\/a>\" by <a href=\"https:\/\/www.bcit.ca\/\" rel=\"noopener noreferrer\">British Columbia Institute of Technology (BCIT)<\/a> is licensed under <a class=\"internal\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/deed.ast\" rel=\"noopener noreferrer\">CC BY 4.0<\/a> <a href=\"#return-footnote-30-1\" class=\"return-footnote\" aria-label=\"Return to footnote 1\">&crarr;<\/a><\/li><li id=\"footnote-30-2\">Fernandez, E., Perez, R., Hernandez, A., Tejada, P., Arteta, M., &amp; Ramos, J. T. (2011). Factors and mechanisms for pharmacokinetic differences between pediatric population and adults. Pharmaceutics, 3(1), 53\u201372. <a class=\"internal\" href=\"https:\/\/doi.org\/10.3390\/pharmaceutics3010053\" rel=\"noopener noreferrer\">https:\/\/doi.org\/10.3390\/pharmaceutics3010053<\/a> <a href=\"#return-footnote-30-2\" class=\"return-footnote\" aria-label=\"Return to footnote 2\">&crarr;<\/a><\/li><li id=\"footnote-30-3\">Fernandez, E., Perez, R., Hernandez, A., Tejada, P., Arteta, M., &amp; Ramos, J. T. (2011). Factors and mechanisms for pharmacokinetic differences between pediatric population and adults. Pharmaceutics, 3(1), 53\u201372. <a class=\"internal\" href=\"https:\/\/doi.org\/10.3390\/pharmaceutics3010053\" rel=\"noopener noreferrer\">https:\/\/doi.org\/10.3390\/pharmaceutics3010053<\/a> <a href=\"#return-footnote-30-3\" class=\"return-footnote\" aria-label=\"Return to footnote 3\">&crarr;<\/a><\/li><\/ol><\/div><div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_30_560\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_30_560\"><div tabindex=\"-1\"><p>The first stage of pharmacokinetics: medications enter the body and travel from the site of administration into the body's circulation.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_30_799\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_30_799\"><div tabindex=\"-1\"><p>The breakdown of orally administered drugs in the liver and intestines.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":90,"menu_order":3,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":"cc-by-nc-sa"},"chapter-type":[50],"contributor":[],"license":[58],"class_list":["post-30","chapter","type-chapter","status-publish","hentry","chapter-type-numberless","license-cc-by-nc-sa"],"part":19,"_links":{"self":[{"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/chapters\/30","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/wp\/v2\/users\/90"}],"version-history":[{"count":8,"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/chapters\/30\/revisions"}],"predecessor-version":[{"id":1607,"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/chapters\/30\/revisions\/1607"}],"part":[{"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/parts\/19"}],"metadata":[{"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/chapters\/30\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/wp\/v2\/media?parent=30"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/pressbooks\/v2\/chapter-type?post=30"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/wp\/v2\/contributor?post=30"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/opentextbc.ca\/nursingpharmacology\/wp-json\/wp\/v2\/license?post=30"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}