VTS week 6 Pharmacology

  1. pharmacodynamics
    how drugs work; mechanism of action
  2. pharmacokinetics
    how drugs move through body
  3. pharmaceutical drug interactions (and 3 causes)
    • drug reactions outside of body
    • 1. incompatible drugs
    • 2. a drug and it's carrier
    • 3. a drug and receptacle
  4. Drug and receptacle interaction & remedy
    • Typically decreases efficacy. 
    • EX: Lipid soluble drugs bind with plastic tubing. Diazepam, insulin, dextrose.
    • Remedy: flush line with 50 mls to saturate plastic
  5. Drugs that have decrease absorption with food (3)
    • 1. Ampicillin
    • 2. Tetracycline
    • 3. Theophylline
  6. Drugs that have delayed absorption with food (4)
    • 1. Cephalexin
    • 2. Cimetidine
    • 3. Digoxin
    • 4. fluoroquinolones
  7. Drugs that have increased absorption with food (2)
    • 1. Diazepam
    • 2. Propranolol
  8. Why does sucralfate inhibit action of other drugs?
    Can prevent absorption of other drugs
  9. What drug interaction inhibits the action of sucralfate?
    Sucralfate requires acidic environment, drugs that increase gastric pH so can inhibit the action of sucralfate.
  10. Drugs that can inhibit the absorption of other drugs in GI tract (4)
    • 1. Sucralfate
    • 2. aluminum hydroxide
    • 3. antacids
    • 4. activated charcoal
  11. Pharmacokinetic drug interactions:
    One drug directly alters action of another drug
  12. Synergistic
    Effect arising between 2 or more agents, entities, factors, or substances that is greater than the sum of their individual effects
  13. Pharmacokinetics includes (4)
    • 1. absirotuib
    • 2. distribution
    • 3. biotransformation
    • 4. excretion
  14. Parenteral administration
    Injection or infusion (IV, SQ, IM, ETC)
  15. Administration route with the greatest potential for alteration:
    Oral
  16. Hepatic recirculation
    excreted through bile, delivered to GI tract, potentially absorbed. Recycled instead of excreted may prolong effects.
  17. What administration route(s) may be affected by hydration status and temperature
    SQ and IM
  18. Dehydrated or hypothermic produces what absorption rate
    • poor absorption for IM or SQ
    • Once rehydrated or warmed may cause rapid absorption +/- overdose
  19. What can alter absorption of topical medications (3)
    • 1. Skin inflammation
    • 2. abrasion
    • 3. body temp
  20. How are aerosolized drugs absorbed
    Absorbed directly into bloodstream through alveoli
  21. What can impair absorption of aerosolized drugs? (3)
    • 1. Parenchymal lung dz
    • 2. vascular shunting
    • 3. tachypnea
  22. How does tachypnea affect absorption of aerosolized drugs
    Drug stays in physiologic dead space of bronchi instead of reaching alveoli
  23. Drug distribution can be affected by (4)
    • 1. drug pH
    • 2. ionization
    • 3. lipid or water solubility
    • 4. affinity for plasma proteins
  24. Lipid soluble drug distribution:
    distributed to all body water, both intracellular and extracellular
  25. Water soluble drug distribution:
    Extracellular fluid compartments only
  26. How can hydration/volume of ECF affect water soluble drugs
    • Volume of ECF can be altered w/ dz (hypovolemia decreased ECF)
    • Depleted water shifts to intracellular compartment, increased concentration of drug in ECF, poss toxicity
    • Edema increases ECF, decreases drug concentration
  27. How do cavitary effusions benefit drug distribution
    Cavitary effusions do not benefit drug distribution, care should be taken when calculating for added mass.
  28. What does blood brain barrier do?
    Protects sensitive nervous tissue from exposure to certain chemicals and compounds.
  29. How does BBB work?
    Capillaries in brain have tight junctions, restricting access to certain particles. Other particles can pass BBB with specific carrier-mediated transport. Glial cells from neurons also have astrocytic end-feet that can restrict access.
  30. How does cranial trauma affect BBB?
    Can increase permeability
  31. Liver shunt effects on drug distribution
    • Liver shunts prevent distribution of drugs to the liver
    • Toxicity if drug is active and remains in circulation, failure of therapy if relies on liver biotransformation
  32. Major site of drug metabolism is _________
    liver
  33. Hepatic metabolism
    converts drugs to water soluble compounds that are excreted, primarily by kidney
  34. Prodrug
    Drug administered in inactive form that is metabolized into active metabolite
  35. Phase 1 metabolism
    Microsomal enzyme system (cytochrome P-450 or CYP) metabolizes many drugs. Hundreds of groups of CYP expressed in liver, intestines, kidney, brain, and other organs.
  36. What do CYP do to drugs (3)
    • 1. Converts some to active prodrugs
    • 2. Converts some to inactive metabolites
    • 3. Converts some to toxic metabolites
  37. Drugs that CYP converts to active prodrugs (3)
    • 1. codeine
    • 2. tramadol
    • 3. enalapril
  38. Drugs that CYP converts to inactive metabolites (2)
    • 1. Warfarin
    • 2. Phenytoin
  39. Drugs that CYP converts to toxic metabolite (1)
    Acetaminophen
  40. Phase 2 metabolism:
    • Conjugation of drug or metabolite with certain pathways/functional groups to increase water solubility
    • Ex: Cats lack glucuronidation (conjugation molecule that binds to substrate), causes increased toxicity of acetaminophen as CYP is utilized instead and produces a toxic metabolite
  41. Primary site of drug excretion
    Kidneys
  42. Possible sites of drug excretion (5)
    • 1. liver
    • 2. GI tract
    • 3. skin
    • 4. mammary tissue
    • 5. lungs
  43. Rate of excretion in kidneys can be affected by (8)
    • 1. renal blood flow
    • 2. glomerular filtration
    • 3. protein binding
    • 4. tubular secretion
    • 5. tubular reabsorption
    • 6. drug lipid solubility
    • 7. molecular size
    • 8. ionization
  44. What percent of cardiac output does kidney receive in bloodflow?
    25%
  45. Drugs to avoid or use with caution with impaired renal function (8)
    • 1. Aminoglycosides
    • 2. tetracyclines
    • 3. sulfonamides
    • 4. NSAIDs
    • 5. corticosteroids
    • 6. ACE inhibitors
    • 7. antiarrhythmics
    • 8. diuretics
Author
anubis_star
ID
351642
Card Set
VTS week 6 Pharmacology
Description
VTS week 6
Updated