Author Question: Which of the following numbers could be the therapeutic index (TI) of a drug for which there is the ... (Read 71 times)

chads108 · **on:** Jul 23, 2018

Which of the following numbers could be the therapeutic index (TI) of a drug for which there is the greatest possibility of toxicity?

a. 2
b. 1
c. 5
d. 10

Question 2

Which substance produces a response equal to or greater than the effects of an endogenous chemical in the body?

a. Competitive inhibitor
b. Noncompetitive inhibitor
c. Antagonist
d. Agonist

cuttiesgirl16 · **Reply #1 on:** Jul 23, 2018

Answer to Question 1

ANS: B
A drug's TI expresses the relative safety of a drug. TI relates the dose of a drug required to pro-duce a desired effect to that producing an adverse or toxic response. Drugs with a high TI are said to be safe (i.e., to have a wide margin of safety). Those with a low TI are relatively unsafe and have the narrowest margin of safety, therefore the greatest possibility of toxicity.

Answer to Question 2

ANS: D
Agonists combine with receptors to initiate events; that is, they have intrinsic activity that is produced by two different mechanisms. Agonist I drugs bind to the same site as an endogenous substance (e.g., neurotransmitter) to produce a similar response. The response usually equals, or is greater than, that of the endogenous substance. Agonist II drugs bind to different extracellular sites, with no response produced solely in the presence of the agonist. However, an enhanced re-sponse is generated when an existing endogenous substance also binds to its site.