MCQ OF Pharmacology
Multiple choice question
3.1 Which of the following drugs acts by inhibiting an enzyme in the body:
A. Atropine
B. Allopurinol
C. Levodopa
D. Metoclopramide
3.2 The following is a competitive type of enzyme inhibitor:
A. Acetazolamide
B. Disulfiram
C. Physostigmine
D. Theophylline
3.3 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
3.4 Drugs acting through receptors exhibit the following features except:
A. Structural specificity
B. High potency
C. Competitive antagonism
D. Dependence of action on lipophilicity
3.5 Study of drug-receptor interaction has now shown that:
A. Maximal response occurs only when all receptors are occupied by the drug
B. Drugs exert an ‘all or none’ action on a receptor
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
3.6 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
3.7 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
3.8 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
3.9 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
3.10 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
3.11 Which of the following is a G protein coupled receptor:
A. Muscarinic cholinergic receptor
B. Nicotinic cholinergic receptor
C. Glucocorticoid receptor
D. Insulin receptor
3.12 The following receptor has an intrinsic ion channel:
A. Histamine H1 receptor
B. Histamine H2 receptor
C. Adrenergic alpha receptor
D. GABA-benzodiazepine receptor
3.13 Select the receptor that is located intracellularly:
A. Opioid μ receptor
B. Steroid receptor
C. Prostaglandin receptor
D. Angiotensin receptor
3.14 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
3.15 All of the following subserve as intracellular second messengers in receptor mediated signal transduction except:
A. Cyclic AMP
B. Inositol trisphosphate
C. Diacylglycerols
D. G proteins
3.16 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
3.17 A receptor which itself has enzymatic property is:
A. Insulin receptor
B. Progesterone receptor
C. Thyroxine receptor
D. Glucagon receptor
3.18 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
3.19 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
3.20 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. Non receptor mediated action
3.21 Which of the following drugs exhibits ‘therapeutic window’ phenomenon:
A. Captopril
B. Furosemide
C. Diazepam
D. Imipramine
3.22 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
3.23 ‘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 therapeutic effect
3.24 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
3.25 Higher efficacy of a drug necessarily confers:
A. Greater safety
B. Therapeutic superiority
C. Capacity to produce more intense response
D. Cost saving
ANSWERS
3.1 B 3.2 C 3.3 C 3.4 D 3.5 D 3.6 A 3.7 C 3.8 C 3.9 C 3.10 D 3.11 A 3.12 D 3.13 B 3.14 C 3.15 D 3.16 C 3.17 A 3.18 A 3.19 B 3.20 C 3.21 D 3.21C 3.21 D 3.22 D 3.23B 3.24 D 3.25 C
