Loading....
Coupon Accepted Successfully!

Pharmacology

Open Flashcards

General Pharmacology

Question
55 out of 91
 

True about efficacy and potency of drugs: (LQ)



A Efficacy is clinically more important than potency

B Height of DRC corresponds to efficacy

C The amount of drugs to produce certain response is called efficacy

D Drugs having similar pharmacological action may have different efficacy

Ans. A B and D Efficacy is clinically more important than potency; Height of DRC corresponds to efficacy; and Drugs having similar pharmacological action may have different efficacy

Go through the difference between potency and efficacy and the options will unfold automatically.

  1. Drug B is less potent but equally efficacious as drug A.
  2. Drug C is less potent and less efficatious than drug A, but equally potent and less efficacious than drug B.
  3. Drug D is more potent than drugs A, B & C, but less efficacious than drugs A & B and equally efficacious as drug C.

Potency

  1. Potency refers to the amount of drug needed to produce a certain response. Drugs A and 8, are said to be more potent than drugs C and D because of the relative positions of their dose response curves along the dose axis.
  2. Competitive antagonist acts by decreasing the potency of a drug, such that maximal response (efficacy) can still be attained by increasing dose of agonist. Causes rightward shift of ORC.
  3. Potency refers to the concentration (EC50) or dose (ED50) of a drug required to produced 50% of that drugs maximal effect.
  4. Potency of a drug depends in part on the efficiency with which drug receptor interaction is coupled to response.

Efficacy

  1. Efficacy refers to the maximal response that can be elicited by the drug. It refers to the maximum height of the curve. Drugs A and B have higher efficacy as compared to C and D.
  2. Non competitive antagonist acts by decreasing the efficacy of a drug. Maximal response is suppressed and unsurmountable. Causes flattening of DRC.
  3. The efficacy of a drug is obviously crucial for making clinical decisions when a large response is needed. It is a more decisive factor in the choice of a drug.
  4. It may be determined by the drug’s mode of interactions with receptors or by characteristics of the receptor system involved.

Option 'd': Drugs having similar pharmacological action may have different efficacy e.g. Morphine produced a degree of analgesia not to be obtained with any dose of aspirin.

General Pharmacology Flashcard List

91 flashcards
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
13)
14)
15)
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
28)
29)
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
54)
55)
56)
57)
58)
59)
60)
61)
62)
63)
64)
65)
66)
67)
68)
69)
70)
71)
72)
73)
74)
75)
76)
77)
78)
79)
80)
81)
82)
83)
84)
85)
86)
87)
88)
89)
90)
91)