Pharmacology Questions and Answers Part-2

1. `Diffusion of drugs across cell membrane:
a) Is dependent upon metabolic activity of the cell
b) Is competitively inhibited by chemically related drugs
c) Is affected by extent of ionization of drug molecules
d) Exhibits saturation kinetics

Answer: c

2. Which of the following drugs is most likely to be absorbed from the stomach:
a) Morphine sulfate
b) Diclofenac sodium
c) Hyoscine hydrobromide
d) Quinine dihydrochloride

Answer: b

3. Which of the following is a weakly acidic drug:
a) Atropine sulfate
b) Chloroquine phosphate
c) Ephedrine hydrochloride
d) Phenytoin sodium

Answer: d

4. The most important factor which governs diffusion of drugs across capillaries other than those in the brain is:
a) Blood flow through the capillary
b) Lipid solubility of the drug
c) pKa value of the drug
d) pH of the medium

Answer: a

5. Active transport of a substance across biological membranes has the following characteristics except:
a) It is specific
b) It is pH dependent
c) It is saturable
d) It requires metabolic energy

Answer: b

6. Tricyclic antidepressants can alter the oral absorption of many drugs by:
a) Complexing with the other drug in the intestinal lume
b) Altering gut motility
c) Altering gut flora
d) Damaging gut mucosa

Answer: b

7. Bioavailability of drug refers to:
a) Percentage of administered dose that reaches systemic circulation in the unchanged form
b) Ratio of oral to parenteral dose
c) Ratio of orally administered drug to that excreted in the f
d) Ratio of drug excreted unchanged in urine to that excreted as metabolites

Answer: a

8. Bioavailability differences among oral formulations of a drug are most likely to occur if the drug:?
a) Is freely water soluble
b) Is completely absorbed
c) Is incompletely absorbed
d) Undergoes little first-pass metabolism

Answer: c

9. The most important factor governing absorption of a drug from intact skin is:
a) Molecular weight of the drug
b) Site of application
c) Lipid solubility of the drug
d) Nature of the base used in the formulation

Answer: C

10. If the total amount of a drug present in the body at a given moment is 2.0 g and its plasma concentration is 25 μg/ml, its volume of distribution is:
a) 100 L
b) 80 L
c) 60 L
d) 50 L

Answer: B