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Kaplan Qbank USMLE



Author9 Posts
  #1

An antagonist is a type of drug that:

A. has maximal efficacy
B. has affinity for a receptor but little efficacy
C. binds to a receptor and activates it
D. has efficacy but low affinity
E. decreases the concentration of an agonist required to produce an effect

Thanks

  #2

d?


  #3

B?

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  #4

I guess it is B as antagonist has more affinity to bind with receptor


  #5

B

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  #6

B

  #7

once again (after the fact ) b looks correct my thinking being that a partial agonist could be an antagonist because [it has great affinity but little efficacy] eg. morphine and pentazocine. If its close to y axis it has high affinity for receptor/ efficacy think about height in a graph. Most of time antagonism is competiive eg. Norepi and propanolol at beta 1 receptors. hope this helps

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  #8

Thank you very much

I think B is correct. I agree with mjl1717, according to katzung most antagonists are actually partial agonists.

  #9

great deduction Hilfer. Good q in that it covered efficacy, potency, affinity ,antagonist, agonist, and it makes one invision a graph.nod

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