Drug excretion
- 1. Susan Ross, Lindsay Leiter, Bonnie Schlicker
- 2. What is excretion? The elimination of waste products by an organism.
- 3. Humans Humans excrete waste products through: Urine Feces Expired air (CO2) Sweat Saliva Breast milk
- 4. What about medicine? Think of the last time you were sick. You most likely took some sort of medication that eventually helped you feel well again. But what happened to the medicine once it completed its task? It must be excreted!!!
- 5. Pharmacology- study of drugs and their interactions with living systems. Pharmacokinetics- drug movement 1. Absorption Route from administration site to the bloodstream IV, Injection, Oral, or Topical 2. Distribution Bloodstream to the site of action Fig. 1-Pharmacokinetics: Absorption, distribution, metabolism, and elimination.
- 6. Pharmacokinetics 3. Metabolism The breakdown of chemical structure by the liver 4. Excretion The elimination of a medication from the body primarily through the kidneys. Fig. 2-Absorption, distribution, metabolism, and excretion in the human body.
- 7. Kidney Anatomy Fig. 4 A single nephron unit.Fig. 3 Longitudinal section of the kidney
- 8. Glomerular Filtration Begins at the glomerulus Consists of a capillary network surrounded by Bowman's capsule Small pores perforate the capillary walls Drugs are forced through these pores This process moves drugs from the blood into the tubular urine. Fig. 5-Renal corpuscle
- 9. Passive Tubular Reabsorption Blood vessels to the glomerulus meet up with the renal distal tubule. Here, concentration of drugs in the blood are lower than drugs in the tubule. This concentration gradient acts as a driving force to move drugs from the tubule back into the blood (reabsorption). Fig. 6-Glomerular capsule. http://kvhs.nbed.nb.ca/gallant/biology/nephron_structu re.html
- 10. Active Tubular Secretion Drugs are pumped from the blood to tubular urine via active transport systems. An area of lower concentration toward an area of higher concentration. Requires energy Tubular cells contain P- glycoprotein in their membranes, which pump drugs into urine. Fig. 7-Renal drug xcretion.
- 11. The End (of Drug Movement)
- 12. References Lehne, R. A. (2013). Pharmacology for nursing care. 8th Ed. St. Louis, Mo: Elsevier/Saunders. Lewis, Sharon. Medical-Surgical Nursing: Assessment and Management of Clinical Problems, 8th Edition. Mosby, 2011. <vbk:9780323065801>. Urinary System. (n.d.). Retrieved August 30, 2013, from http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/A PII Notes3%20urinary%20system.htm Wissman, J., Knippa, A., Lawler, K. M., Stacy, B. L., & Assessment Technologies Institute. (2008). Pharmacology for nursing. Overland Park, KS: Assessment Technologies Institute.