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Pharmacology Exam 2

  1. cytokine receptors ligands
    • growth hormone
    • epo
    • interferons
  2. Cytokine receptor cascade
    • protein tyrosine kinase non intrinsic
    • JAK binds non covalently to the receptor and tyr are phosphorylated
    • STAT binds each JAK
    • STATs dimerize and regulate transcription of genes
  3. Regulation of ion channels
    • phosphorylation
    • endocytosis
  4. verapamil
    • inhibits voltage gated Ca2+ channels in heart muscle
    • reduces arrhythmia
    • reduces blood pressure
  5. Propranolol
    • binds B-adrenoreceptors
    • reduces blood pressure
  6. EC50
    concentration required to achieve 50% of the drugs maximal effect
  7. ED50
    dose of a drug required to produce 50% of a drug's maximal effect
  8. Potency
    • amount of drug needed to produce 50% of the drug's maximal effect
    • depends on drug affinity (Kd)
    • depends on efficiency of the drug receptor interaction response
  9. Potency of drug on graph
    • left = most potent
    • right = least potent
  10. low Kd
    high affinity
  11. Drug on a chart with maximal efficacy
    tallest line on the chart
  12. Clinical effectiveness depends on
    • potency (ec50)
    • maximal efficacy
    • ability of drug to reach the relevant receptors
  13. is effectiveness or potency more desired?
    effectiveness > potency
  14. ____ the potency of a drug should be stated in dosage units in terms of particular outcomes.
    therapeutic purposes
  15. Relative potencey
    ratio of equi-effective doses that may be used in comparing one drug to another
  16. Maximal efficacy
    • limit of the dose response
    • hight of the line on the graph
  17. Therapeutic efficacy
    • effect that can be achieved in the patient
    • depends on drug-receptor interactions
  18. Quantal dose effect plots
    shaded boxes indicate the frequency distribution of doses required to produce a specified effect
  19. ED50
    Median effective dose at which 50% of individuals exhibit the specified quantal effect
  20. TD50
    Median Toxic Dose is the dose required to produce a particular toxic effect in 50% of the animals.
  21. LD50
    Median lethal dose is the dose that causes death in 50% of the animals
  22. If the ED50 of two drugs for producing a specified quantal effect are 5 and 500 mg then:
    the first drug can be said to be 100 times more potent than the second for that effect
  23. measure which relates the dose of a drug required to produce a desired effect to that which produces an undesired effect
    therapeutic index
  24. therapeutic index is usually defined as
    ratio of TD50 to the ED50
  25. idiosyncratic drug response
    individual exhibit an unusual response to the drug
  26. When responsiveness diminishes rapidly after administration of a drug, the response is said to be
    tachyphylaxis
  27. Four mechanisms which may contribute to variation in drug responsiveness among patients
    • alteration in concentration of dose that reaches the receptor
    • variation in concentration of an endogenous receptor ligand
    • alteration in number or function of receptors
    • changes in components of response distal to the receptor
  28. Multi drug resistance genes
    • MDR
    • major mechanism by which tumor cells develop resistance to anticancer drugs
  29. drugs are ____ rather than specific
    selective
  30. Measurement of selectivity of a drug
    • compare binding affinities
    • compare ED50s for different effects of a drug in vivo
  31. selectivity is usually considered by separating effects into two categories
    therapeutic effects vs. toxic effects
Author
Rx2013
ID
39181
Card Set
Pharmacology Exam 2
Description
Drug receptor concepts II and III
Updated

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