MCQ OF Pharmacology
- 2.1 Alkalinization of urine hastens the excretion of:
A. Weakly basic drugs
B. Weakly acidic drugs
C. Strong electrolytes
D. Nonpolar drugs
- 2.2 Majority of drugs cross biological membranes primarily
by:
A. Passive diffusion
B. Facilitated diffusion
C. Active transport
D. Pinocytosis
- 2.3 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
- 2.4 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
- 2.5 Which of the following is a weakly acidic drug:
A. Atropine sulfate
B. Chloroquine phosphate
C. Ephedrine hydrochloride
D. Phenytoin sodium
- 2.6 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
- 2.7 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
- 2.8 Tricyclic antidepressants can alter the oral absorption
of many drugs by:
A. Complexing with the other drug in the intestinal lumen
B. Altering gut motility
C. Altering gut flora
D. Damaging gut mucosa
- 2.9 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 faeces
D. Ratio of drug excreted unchanged in urine to
that excreted as metabolites
- 2.10 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
- 2.11 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
- 2.12 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
- 2.13 The following attribute of a drug tends to reduce its
volume of distribution:
A. High lipid solubility
B. Low ionisation at physiological pH values
C. High plasma protein binding
D. High tissue binding
- 2.14 Marked redistribution is a feature of:
A. Highly lipid soluble drugs
B. Poorly lipid soluble drugs
C. Depot preparations
D. Highly plasma protein bound drugs
- 2.15 A nonvolatile, highly lipid soluble drug is metabolized
at a rate of 15% per hour. On intravenous injection it
produces general anaesthesia for 10 min. Which process is responsible for termination of its action:
A. Metabolism in liver
B. Plasma protein binding
C. Excretion by kidney
D. Redistribution
- 2.16 The blood-brain barrier, which restricts entry of many
drugs into brain, is constituted by:
A. P-glycoprotein efflux carriers in brain
capillary cells
B. Tight junctions between endothelial cells of
brain capillaries
C. Enzymes present in brain capillary walls
D. All of the above
- 2.17 Which of the following is not true of the blood-brain
barrier:
A. It is constituted by tight junctions between
the endothelial cells of brain capillaries and
the glial tissue
B. It allows passage of lipid soluble drugs into
the brain
C. It limits entry of highly ionized drugs into the brain
D. It regulates passage of substances from brain
into blood
- 2.18 Weakly acidic drugs:
A. Are bound primarily to α1 acid glycoprotein in
plasma
B. Are excreted faster in alkaline urine
C. Are highly ionized in the gastric juice
D. Do not cross blood-brain barrier
- 2.19 High plasma protein binding:
A. Increases volume of distribution of the drug
B. Facilitates glomerular filtration of the drug
C. Minimises drug interactions
D. Generally makes the drug long acting
- 2.20 The plasma protein bound fraction of a drug:
A. Contributes to the response at the given moment
B. Remains constant irrespective of the total drug
concentration
C. Remains constant irrespective of the disease state
D. Is not available for metabolism unless actively
extracted by the liver.
ANSWERS
2.1 B
2.2 A
2.3 C
2.4 B
2.5 D
2.6 A
2.7 B
2.8 B
2.9 A
2.10 C
2.11 C
2.12 B
2.13 C
2.14 A
2.15 D
2.16 D
2.17 D
2.18 B
2.19 D
2.20 D
