Pharmacology Questions and Answers





1. `Essential drugs’ are:
a) Life saving drugs
b) Drugs that meet the priority health care needs of the population
c) Drugs that must be present in the emergency bag of a doctor
d) Drugs that are listed in the pharmacopoia of a country

Answer: b

2. An 'orphan drug' is:
a) A very cheap drug
b) A drug which has no therapeutic use
c) A drug needed for treatment or prevention of a rare disease
d) A drug which acts on Orphanin receptors

Answer: c

3. Drug administered through the following route is most likely to be subjected to first-pass metabolism:
a) Oral
b) Sublingual
c) Subcutaneous
d) Rectal

Answer: a

4. Transdermal drug delivery systems offer the following advantages except:
a) They produce high peak plasma concentration of the drug
b) They produce smooth and nonfluctuating plasma concentration of the drug
c) They minimise interindividual variations in the achieved plasma drug concentration
d) They avoid hepatic first-pass metabolism of the drug

Answer: a

5. In addition to slow intravenous infusion, which of the following routes of administration allows for titration of the dose of a drug with the response:
a) Sublingual
b) Transdermal
c) Inhalational
d) Nasal insufflation

Answer: c

6. Which of the following drugs is administered by intranasal spray/application for systemic action:
a) Phenylephrine
b) Desmopressin
c) Azelastine
d) Beclomethasone dipropionate

Answer: b

7. Compared to subcutaneous injection, the intramuscular injection of
a) Is more painful
b) Produces faster response
c) Is unsuitable for depot preparations
d) Carries greater risk of anaphylactic reaction

Answer: b

8. Select the route of administration which carries the highest risk of adversely affecting vital functions:
a) Intra arterial injection
b) Intrathecal injection
c) Intravenous injection
d) Intramuscular injection

Answer: c

9. Alkalinization of urine hastens the excretion of
a) Weakly basic drugs
b) Weakly acidic drugs
c) Strong electrolytes
d) Nonpolar drugs

Answer: b

10. Majority of drugs cross biological membranes primarily by:
a) Passive diffusion
b) Facilitated diffusion
c) Active transport
d) Pinocytosis

Answer: a

11. `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

12. 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

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

Answer: d

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. `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

Answer: c

22. 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

Answer: a

23. 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

Answer: d

24. 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

Answer: d

25. 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

Answer: d

26. 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

Answer: b

27. 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

Answer: d

28. 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

Answer: d

29. Biotransformation of drugs is primarily directed to:
a) Activate the drug
b) Inactivate the drug
c) Convert lipid soluble drugs into nonlipid soluble metabolites
d) Convert nonlipid soluble drugs into lipid soluble metabol

Answer: C

30. Which of the following is a prodrug
a) Hydralazine
b) Clonidine
c) Captopril
d) Enalapril

Answer: d

31. A prodrug is:
a) The prototype member of a class of drugs
b) The oldest member of a class of drugs
c) An inactive drug that is transformed in the body to an active metabolite
d) A drug that is stored in body tissues and is then gradually released in the circulation

Answer: c

32. Which of the following cytochrome P450 isoenzymes is involved in the metabolism of largest number of drugs in human beings and has been implicated in some dangerous drug interactions:
a) CYP 3A4
b) CYP 2C9
c) CYP 2E1
d) CYP 1A2

Answer: a

33. The following is not true of the cytochrome P450 isoenzyme CYP2D6:
a) It generates the hepatotoxic metabolite N-acetyl benzoquinone immine from paracetamol
b) It is involved in demethylation of codeine into morphine
c) Its altered form is responsible for poor capacity to hydroxylate many drugs including metoprolol
d) It is inhibited by quinidine

Answer: a

34. The most commonly occurring conjugation reaction for drugs and their metabolites is:
a) Glucuronidation
b) Acetylation
c) Methylation
d) Glutathione conjugation

Answer: a

35. Microsomal enzyme induction can be a cause of:
a) Tolerance
b) Physical dependence
c) Psychological dependence
d) Idiosyncrasy

Answer: a

36. The following drug metabolizing reaction is entirely nonmicrosomal:
a) Glucuronide conjugation
b) Acetylation
c) Oxidation
d) Reduction

Answer: b

37. Which of the following types of drug metabolizing enzymes are inducible:
a) Microsomal enzymes
b) Nonmicrosomal enzymes
c) Both microsomal and nonmicrosomal enzymes
d) Mitochondrial enzymes

Answer: a

38. Induction of drug metabolizing enzymes involves:
a) A conformational change in the enzyme protein to favour binding of substrate molecules
b) Expression of enzyme molecules on the surface of hepatocytes
c) Enhanced transport of substrate molecules into hepatocytes
d) Increased synthesis of enzyme protein

Answer: d

39. Select the drug that undergoes extensive first-pass metabolism in the liver:
a) Phenobarbitone
b) Propranolol
c) Phenylbutazone
d) Theophylline

Answer: b

40. Drugs which undergo high degree of first-pass metabolism in
a) Have low oral bioavailability
b) Are excreted primarily in bile
c) Are contraindicated in liver disease
d) Exhibit zero order kinetics of elimination

Answer: a

41. Glomerular filtration of a drug is affected by its:
a) Lipid solubility
b) Plasma protein binding
c) Degree of ionization
d) Rate of tubular secretion

Answer: b

42. If a drug undergoes net tubular secretion, its renal clearance will be:
a) More than the glomerular filtration rate
b) Equal to the glomerular filtration rate
c) Less than the glomerular filtration rate
d) Equal to the rate of urine formation

Answer: a

43. The plasma half life of penicillin-G is longer in the new born because their:
a) Plasma protein level is low
b) Drug metabolizing enzymes are immature
c) Glomerular filtration rate is low
d) Tubular transport mechanisms are not well developed

Answer: d

44. If a drug is excreted in urine at the rate of 10 mg/hr at a steady-state plasma concentration of 5 mg/L, then its renal clearance is:
a) 0.5 L/hr
b) 2.0 L/hr
c) 5.0 L/hr
d) 20 L/hr

Answer: b

45. Which of the following is not a primary/fundamental, but a derived pharmacokinetic parameter
a) Bioavailability
b) Volume of distribution
c) Clearance
d) Plasma half life

Answer: d

46. If a drug is eliminated by first order kinetics:
a) A constant amount of the drug will be eliminated per unit time
b) Its clearance value will remain constant
c) Its elimination half life will increase with dose
d) It will be completely eliminated from the body in 2 half life period

Answer: b

47. If a drug has a constant bioavailability and first order elimination, its maintenance dose rate will be directly proportional to its:
a) Volume of distribution
b) Plasma protein binding
c) Lipid solubility
d) Total body clearance

Answer: d

48. If the clearance of a drug remains constant, doubling the dose rate will increase the steady-state plasma drug concentration by a factor of
a) 3
b) 2
c) 1.5
d) 1.3

Answer: b

49. When the same dose of a drug is repeated at half life intervals, the steady-state (plateau) plasma drug concentration is r
a) 2–3 half lives
b) 4–5 half lives
c) 6–7 half lives
d) 8–10 half lives

Answer: b

50. The loading dose of a drug is governed by its:
a) Renal clearance
b) Plasma half life
c) Volume of distribution
d) Elimination rate constant

Answer: c

51. Monitoring of blood levels of diuretic drugs is not practised because:
a) No sensitive methods for measuring blood levels of diuretics are available
b) It is easier to measure the effect of these drugs
c) Response to diuretics is not related to their blood levels
d) Diuretics need activation in the body

Answer: b

52. Monitoring plasma drug concentration is useful while using:
a) Antihypertensive drugs
b) Levodopa
c) Lithium carbonate
d) MAO inhibitors

Answer: c

53. Sustained/controlled release oral dosage form is appropriate for the following type of drug:
a) An antiarthritic with a plasma half life of 24 hr
b) A sleep inducing hypnotic with a plasma half life of 2 hours
c) An antihypertensive with a plasma half life of 3 hours
d) An analgesic with a plasma half life of 6 hours used for relief of casual headache

Answer: c

54. Microsomal enzyme induction has one of the following features:
a) Takes about one week to developr
b) Results in increased affinity of the enzyme for the substrate
c) It is irreversible
d) Can be used to treat acute drug poisonings

Answer: a

55. Which of the following drugs acts by inhibiting an enzyme in the body
a) Atropine
b) Allopurinol
c) Levodopa
d) Metoclopramide

Answer: b

56. The following is a competitive type of enzyme inhibitor:
a) Acetazolamide
b) Disulfiram
c) Physostigmine
d) Theophylline

Answer: c

57. What is true in relation to drug receptors:
a) All drugs act through specific receptors
b) All drug receptors are located on the surface of the target cells
c) Agonists induce a conformational change in the receptor
d) Partial agonists have low affinity for the receptor

Answer: c

58. Drugs acting through receptors exhibit the following features except:
a) Structural specificity
b) High potency
c) Competitive antagonism
d) Dependence of action on lipophilicity

Answer: d

59. Study of drug-receptor interaction has now shown that
a) Maximal response occurs only when all receptors are occupied by the dru
b) Drugs exert an ‘all or none’ action on a recepto
c) Receptor and drugs acting on it have rigid complementary ‘lock and key’ structural features
d) Properties of ‘affinity’ and ‘intrinsic activity’ are independently variable

Answer: d

60. A partial agonist can antagonise the effects of a full agonist because it has:
a) High affinity but low intrinsic activity
b) Low affinity but high intrinsic activity
c) No affinity and low intrinsic activity
d) High affinity but no intrinsic activity

Answer: a

61. Receptor agonists possess
a) Affinity but no intrinsic activity
b) Intrinsic activity but no affinity
c) Affinity and intrinsic activity with a + sign
d) Affinity and intrinsic activity with a – sign

Answer: c

62. Agonists affect the receptor molecule in the following manner:
a) Alter its amino acid sequence
b) Denature the receptor protein
c) Alter its folding or alignment of subunits
d) Induce covalent bond formation

Answer: c

63. Receptors perform the following function/functions:
a) Ligand recognition
b) Signal transduction
c) Both ligand recognition and signal transduction
d) Disposal of agonists and antagonists

Answer: c

64. The following receptor type has 7 helical membrane spanning amino acid segments with 3 extracellular and 3 intracellular loops:
a) Tyrosine protein kinase receptor
b) Gene expression regulating receptor
c) Intrinsic ion channel containing receptor
d) G protein coupled receptor

Answer: d

65. Which of the following is a G protein coupled recepto
a) Muscarinic cholinergic receptor
b) Nicotinic cholinergic receptor
c) Glucocorticoid receptor
d) Insulin receptor

Answer: a

66. The following receptor has an intrinsic ion channel
a) Histamine H1 receptor
b) Histamine H2 receptor
c) Adrenergic alfa receptor
d) GABA-benzodiazepine receptor

Answer: d

67. Select the receptor that is located intracellularly
a) Opioid μ receptor
b) Steroid receptor
c) Prostaglandin receptor
d) Angiotensin receptor

Answer: b

68. Agonist induced autophosphorylation, internalization and down regulation is a distinctive feature of:
a) G-protein coupled receptors
b) Intrinsic ion channel containing receptors
c) Tyrosine protein kinase receptors
d) Receptors regulating gene expression

Answer: c

69. All of the following subserve as intracellular second messengers in receptor mediated signal transduction except:
a) Cyclic AMP
b) Inositol trisphosphate
c) Diacyl glycerols
d) G proteins

Answer: d

70. The receptor transduction mechanism with the fastest time-course of response effectuation is
a) Adenylyl cyclase-cyclic AMP pathway
b) Phospholipase C-IP3: DAG pathway
c) Intrinsic ion channel operation
d) Protein synthesis modulation

Answer: c

71. A receptor which itself has enzymatic property is
a) Insulin receptor
b) Progesterone receptor
c) Thyroxine receptor
d) Glucagon recepto

Answer: a

72. Down regulation of receptors can occur as a consequence of:
a) Continuous use of agonists
b) Continuous use of antagonists
c) Chronic use of CNS depressants
d) Denervation

Answer: a

73. The following statement is not true of log dose-response curve:
a) It is almost linear except at the ends
b) It is a rectangular hyperbola
c) It facilitates comparison of different agonists
d) It can help in discriminating between competitive and noncompetitive antagonists

Answer: b

74. When therapeutic effects decline both below and above a narrow range of doses, a drug is said to exhibit
a) Ceiling effect
b) Desensitization
c) Therapeutic window phenomenon
d) Nonreceptor mediated action

Answer: c

75. Which of the following drugs exhibits ‘therapeutic window’ phenomenon:
a) Captopril
b) Furosemide
c) Diazepam
d) Imipramine

Answer: d

76. The following statement is not true of ‘potency’ of a drug:
a) Refers to the dose of the drug needed to produce a certain degree of response
b) Can be related to that of its congeners by the relative position of its dose-response curve on the dose axis
c) It is often not a major consideration in the choice of a drug
d) It reflects the capacity of the drug to produce a drastic response

Answer: d

77. ‘Drug efficacy’ refers to:
a) The range of diseases in which the drug is beneficial
b) The maximal intensity of response that can be produced by the drug
c) The dose of the drug needed to produce half maximal effect
d) The dose of the drug needed to produce theraeutic effect

Answer: b

78. Which of the following is always true
a) A more potent drug is more efficacious
b) A more potent drug is safer
c) A more potent drug is clinically superior
d) A more potent drug can produce the same response at lower doses

Answer: d

79. Higher efficacy of a drug necessarily confers:
a) Greater safety
b) Therapeutic superiority
c) Capacity to produce more intense response
d) Cost saving

Answer: c

80. If the dose-response curves of a drug for producing different actions are widely separated on the dose axis, the drug is:
a) Highly potent
b) Highly efficacious
c) Highly toxic
d) Highly selective

Answer: d

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

Answer: a

82. 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

83. 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

84. 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

85. 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

86. 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

87. 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

88. 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

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

Answer: d

90. 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

91. A drug which is generally administered in standard doses without the need for dose individualization is:
a) Insulin
b) Mebendazole
c) Prednisolone
d) Digoxin

Answer: b

92. Which of the following statements is not true of fixed dose combination formulations:
a) They are more convenient
b) Contraindication to one of the components does not contraindicate the formulation
c) The dose of any one component cannot be independently adjusted
d) The time course of action of the different components may not be identical

Answer: b

93. Fixed dose combination formulations are not necessarily appropriate for:
a) Drugs administered in standard doses
b) Drugs acting by the same mechanism
c) Antitubercular drugs
d) Antihypertensive drugs

Answer: b

94. A fixed dose combination preparation meant for internal use must not contain the following class of drug:
a) Thiazide diuretic
b) Fluoroquinolone antimicrobial
c) Corticosteroid
d) H2 blocker

Answer: c

95. Interindividual variations in equieffective doses of a drug are most marked if it is disposed by:
a) Glomerular filtration
b) Tubular secretion
c) Both glomerular filtration and tubular secretion
d) Hepatic metabolism

Answer: d

96. The pharmacokinetics of drugs in the neonate differs from that in adults, because their:
a) Intestinal transit is fast
b) Drug metabolizing enzymes are overactive
c) Tubular transport mechanisms are not well developed
d) Glomerular filtration rate is high

Answer: c

97. Which adverse drug effect is more common in children than in adults:
a) Isoniazid induced neuropathy
b) Chlorpromazine induced muscle dystonia
c) Digoxin induced cardiac arrhythmia
d) Penicillin hypersensitivity

Answer: b

98. The elderly patients are relatively intolerant to
a) Digoxin
b) Salbutamol
c) Propranolol
d) Nifedipine

Answer: a

99. The following drug adverse effect is specially noted in men compared to women:
a) Tardive dyskinesia due to neuroleptics
b) Levodopa induced abnormal movements
c) Ampicillin induced loose motions
d) Ketoconazole induced loss of libido

Answer: d

100. Which racial difference in response to drugs has been mentioned incorrectly below:
a) Africans require higher concentration of atropine to dilate pupils
b) Black races are more responsive to antihypertensive action o
c) Japanese are more prone to develop SMON due to halogenated hydroxyquinolines
d) Chloramphenicol induced aplastic anaemia is rare among Indians

Answer: b