Drug effects on elimination and clearance

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  1. What are the two drug types?
    Water soluble and lipid soluble
  2. What is drug action?
    • drug must get access to sites of action
    • Drugs tend to bind to tissues, usually protein
    • drug alter the action of enzymes, ion channels and receptors
  3. What do drugs do to receptors?
    Drugs activate or block the receptor, activation of the receptor activates a cell signal
  4. What are the law of mass action that applies to drug receptor interaction?
    • Pharmacological effects are reversible because the drug receptor complex is reversible
    • Pharmacological effects are proportional to the number receptors occupied
    • Pharmacological effect plataeu because they are limited by the total number of receptors
    • Drug effects are proportional to the dose!!!
  5. define: potency
    measure amount of drug required for effect
  6. define: efficacy
    maximum effect obtained with drug
  7. define: variability
    reproducibility of data
  8. What is the main determinant in the decline in GFR?
    Renal disease
  9. What drug are eliminated directly by the kids?
    • Water soluble
    • involves no chemical change to the drug
  10. What drugs are readily reabsorbed?
    highly lipid soluble
  11. How do you assess kid fxn?
    serum creatine reflects GFR
  12. How does age affect renal fxn?
    THere is a steady and proportional decline in the average GFR with increase of age
  13. What are the two mechanism how drugs are handled by kids?
    • active tubular secretion
    • passive diffusion, depends on ionization at certain pHs
  14. What should we know about gentamycin?
    • ONce a day dosing, with kid failure dosing increases past once daily
    • toxicity relates to trough concentrations
  15. What should we know about digoxin?
    IN the presence of renal failure must increase the dosing frequency
  16. What are the results of drug concentations with renal failure?
    Accumulation of drug in the body can lead to toxicity
  17. What is first pass metabolism?
    Following non-parental dosage form a significant portion of the dose may be metabolically inactivated in the intestinal endothelium or the liver before it reaches systemic circulation
  18. What is the role of metabolism?
    • Metabolites are less active
    • metabolites are more water soluble and more polar
    • Prodrugs that require metabolism to be active as active metabolites
    • Metabolites are more toxic
  19. What is the phase I reactions of metabolism?
    Convert the parent drug into a more polar metabolite introducing or unmasking a functional group, metabolites are usually inactive
  20. WHat is phase II reaction of metabolism?
    Conjugate an endogenous substrate to a funcational gorup on the drug or phase I metabolite
  21. What happens to pharmacokinetic properties as people age?
    • Acetylation and conjugation do not change
    • Oxidative metabolism by CYP decreases with age resulting in a decreased clearance of drugs
  22. WHat does hepatocellular disease do to the liver?
    Decreases liver perfusion
  23. WHat are the indicators of liver disease?
    Establishe cirrhosis, splenomegaly, jaundice, increased prothrombin time
  24. How can cardiac failure affect the liver?
    Decreas liver perfusion
  25. What are some pharmcodynamic consideration of liver disease?
    Tissues may be excessively sensitive to low concentrations of the drug ex: morphine [] in the brain in the presence of liver failure
  26. What does the liver fxn test consist of?
    • Transaminase
    • Alkaline phosphatase
    • Bilirubin
    • Other liver labs
  27. Why is transaminase part of the LFT?
    because it is released after liver heaptocellular injury
  28. What are the two forms of transaminases?
    • Aspartate aminotransaminase
    • Alanine aminotransaminase: more specific in myopathies
  29. elevated transaminases indicate:
    • acute toxic injusty apap ischemia
    • acute viral disease
    • alcohol heapatitis
  30. What does an elevated AST:ALT
    elevated in alcolic disease
Card Set:
Drug effects on elimination and clearance
2012-03-06 03:46:47
Drug effects elimination clearance

Drug effects on elimination and clearance
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