Pharmacology Questions and Answers Part-9

1. The therapeutic index of a drug is a measure of its:
a) Safety
b) Potency
c) Efficacy
d) Dose variability

Answer: a

2. Compared to the drug named within parenthesis, which of the following drugs has a higher potency but lower efficacy
a) Pethidine (morphine)
b) Furosemide (hydrochlorothiazide)
c) Diazepam (pentobarbitone)
d) Enalapril (captopril)

Answer: c

3. if the effect of combination of two drugs is equal to the sum of their individual effects, the two drugs are exhibiting:
a) Potentiation
b) Synergism
c) Cross tolerance
d) Antagonism

Answer: b

4. The antagonism between adrenaline and histamine is called ‘physiological antagonism’ because:
a) Both are physiologically present in the body
b) They act on physiological receptors
c) Both affect many physiological processes
d) They have opposite physiological effects

Answer: d

5. The antidotal action of sodium nitrite in cyanide poisoning is based
a) Physical antagonism
b) Chemical antagonism
c) Physiological antagonism
d) Noncompetitive antagonism

Answer: b

6. A drug ‘R’ producing no response by itself causes the log dose-response curve of another drug ‘S’ to shift to the right in a parallel manner without decreasing the maximal response: Drug ‘R’ is a:
a) Partial agonist
b) Inverse agonist
c) Competitive antagonist
d) Noncompetitive antagonist

Answer: c

7. A drug which does not produce any action by itself but decreases the slope of the log dose-response curve and suppresses the maximal response to another drug is a:
a) Physiological antagonist
b) Competitive antagonist
c) Noncompetitive antagonist
d) Partial agonist

Answer: c

8. The following is not a feature of competitive antagonists
a) Chemical resemblance with the agonist
b) Parallel rightward shift of the agonist log doseresponse curve
c) Suppression of maximal agonist response
d) Apparent reduction in agonist affinity for the receptor

Answer: c

9. The following is a competitive antagonist of GABA but a noncompetitive antagonist of diazepam:
a) Picrotoxin
b) Muscimol
c) Flumazeni
d) Bicuculline

Answer: d

10. The dose of the following class of drugs has to be adjusted by repeated measurement of the affected physiological parameter:
a) Oral contraceptives
b) Antiepileptics
c) Antidepressants
d) Oral anticoagulants

Answer: d