Deck 4: Comprehensive Pharmacology Questions and Case Studies

Question 1

A 66-year-old man is admitted to the hospital with confusion, nausea, and blurred vision. He is currently on digoxin for the treatment of heart failure. On physical exam, his heart rate is 120 bpm. Further evaluation reveals a digoxin level of 5.3 ng/mL (normal range: 0.5-2 ng/mL). The doctor believes his symptoms are due to digoxin toxicity. Which parameter is used to indicate the ability of digoxin to produce the desired effect relative to a toxic effect?

A) Bioavailability
B) Efficacy
C) Intrinsic activity
D) Potency
E) Therapeutic index

Answer 1

Therapeutic index

Question 2

A 24-year-old female is prescribed erythromycin for gastroparesis. It is prescribed four times daily due to its short half-life. What is the rationale for such a frequent dosing?

A) Achieve the steady-state plasma concentration of the drug
B) Aid more complete distribution of the drug
C) Avoid the toxicity of the drug because of its low therapeutic index
D) Ensure that the drug concentration remains constant over time
E) Inhibit the first-pass metabolism of the drug

Answer 2

Avoid the toxicity of the drug because of its low therapeutic index

Question 3

Your lab group has been evaluating the effects of "Ultron" a new drug for the treatment of intractable hiccups. When administered over a wide concentration range, three dose response relationships were defined in test subjects. Using facial flushing as an unwanted side effect, what would be the estimated therapeutic index for Ultron?

A) 0.1
B) 100
C) 10
D) Can't determine

Answer 3

10

Question 4

Digoxin is a drug that has been used to treat systolic heart failure for over 200 years. It has a therapeutic index value of 2. How many daily doses of digoxin will the average patient have to take at one time to have a 50:50 chance of developing toxic side effects?

A) One
B) Two
C) I don't know

Question 5

Drugs with low efficacy bind to receptors but do not fully activate them. Such "partial agonists" can act as either as a weak agonist (in the absence of a full agonist), or as a competitive antagonist (if a full agonist is present). Which curve best reflects the effect produced by this type of agonist when it is administered alone?

A) A
B) B
C) C
D) D
E) E

Question 6

This graph illustrates the dose-response relationship for the effect of the beta agonist isoproterenol on an isolated perfused heart, both alone and in the presence of different fixed concentrations of Drug X. Based upon the data shown, Drug X is most likely a(n):

A) beta agonist
B) competitive antagonist
C) irreversible antagonist
D) noncompetitive antagonist

Question 7

This graph shows the concentration-dependent effects of norepinephrine on arterial blood pressure, both alone, and in the presence of a fixed concentration of Drug X. Which type of antagonist is Drug X?

A) Silent
B) Non - competitive
C) Competitive
D) Chemical

Question 8

Angina is caused by:

A) Blocking beta1 receptors with a constant binding of noradrenaline
B) Activating beta2 receptors
C) Beta1 receptors are not active anymore
D) Extreme binding of noradrenaline due to up regulation

Question 9

What is correct concerning TI:

A) A safer drug has a higher theraputic index
B) TI might be equal to 1
C) The more the unwanted adverse effect, the ration decreases
D) You are in danger if you take 1.8 ng/ml of Digoxin which has the margin of safety (0.8-2)

Question 10

What is the correct statement concerning noncompetitive antagonism:

A) The potency of the drug does not change
B) the number of receptors able to bind the agonist is affected
C) by increasing the conc. of the agonist, we cannot overcome the problem
D) non of the above is wrong

Question 11

A patient comes to the ER having his quadriceps muscle constantly contracted, you should give him:

A) Norepinephrine to stimulate the sympathetic nervous system
B) An antagonist for Norepinephrine
C) Acetylcholinesterase
D) Agonist for acetylcholine
E) b and d are correct

Question 12

Dose response data was collected during the preclinical testing of four drugs for the treatment of acute heart failure.

A. Which drug studied was the most efficacious?
B. Of the four drugs shown, which is the most potent?

Question 13

As a clinical consultant for the Breathright drug research firm, you are given the task of using an in vitro assay to screen ten thousand drug analogs to find the most potent beta-2 receptor agonist. When analysing your data, the biomarker that you should screen for is:

A) E max
B) Emax
C) EC50
D) Half life
E) Toxicity

Question 14

Mutations in receptor tyrosine kinases would most likely be associated with :

A) Neurologic diseases
B) Endocrine diseases
C) Cancers
D) Metabolic abnormalities

Question 15

A newly developed medication for pulmonary hypertension targets blood vessels in the lungs, but does not affect blood vessels in the liver. Which of the following is most likely true of this medication?

A) It is a ligand that is specific for lung and liver blood-vessel receptors. but which is metabolized rapidly in the liver
B) It is a ligand that is specific for blood-vessel receptors in the lung but not in the liver
C) It is a receptor that is upregulated when oxygen tension in the lungs is low
D) It is a receptor that is only expressed on blood vessels in the lungs

Question 16

In which type of cell are ligand-gated ion channels most commonly found?

A) Cells that are terminally differentiated
B) Cells that produce large proteins
C) Cells that need to respond quickly to external stimuli
D) Cells that respond to mechanic forces

Question 17

Which of the following is NOT true regarding ligand-gated ion channels?

A) React quickly to a stimulus or ligand
B) Can have intracellular binding sites
C) Can exhibit allosteric binding
D) Open or close in response to deformations in the cell membrane

Question 18

Once phosphorylated, the intracellular segment of a receptor tyrosine kinase

A) Activates adenylate cyclase
B) Causes dissociation of the ligand from an allosteric binding site
C) Terminates intracellular signaling cascades
D) Allows docking of intracellular proteins involved in signal transduction

Question 19

Isoproterenol produces maximal contraction of cardiac muscle in a manner similar to epinephrine . Which of the following best describe isoproterenol ?

A) Fuller agonist
B) Partial agonist
C) Irreversible antagonist
D) Inverse agonist

Question 20

If 10 mg of naproxen produces the same analgesic response as 100 mg of ibuprofen , which of the following statements is correct ?

A) Naproxen is more efficacious than is ibuprofen
B) Naproxen is more potent than ibuprofen
C) Naproxen is full agonist , and ibuprofen is a partial agonist .
D) Naproxen is a competitive antagonist .
E) Naproxen is a better drug to take for pain relief than is ibuprofen .

Question 21

If a 10 mg morphine produces a greater analgesic response than can achieved by ibuprofen at any dose , which of the following statements is correct ?

A) Morphine is less efficacious than is ibuprofen .
B) Morphine is less potent than is ibuprofen .
C) Morphine is a full agonist , and ibuprofen is a partial agonist .
D) Ibuprofen is ab competitive antagonist .
E) Morphine is a better drug to take for pain relief than is ibuprofen .

Question 22

In the presence of naloxone , a higher concentration of morphine is required to elicit full pain relief . Naloxone by it self has no effect . Which of the following is correct regarding these medications ?

A) Naloxone is a competitive antagonist .
B) Morphine is a full agonist , and naloxone is a partial agonist .
C) Morphine is less efficacious than is naloxone .
D) Morphine is less potent than is naloxone .
E) Naloxone is a noncompetitive antagonist .

Question 23

In the presence of pentazocine , a higher concentration of morphine is required to elicit pain relief . Pentazocine by it self has a smaller analgesic effect than does morphine , even at the highest dose , Which of the following is correct regarding these medications ?

A) Pentazocine is a competitive antagonist .
B) Morphine is a full agonist , and pentazocine is a partial agonist .
C) Morphine is less efficacious than is pentazocine .
D) Morphine is less potent than is pentazocine .
E) Pentazocine is a noncompetitive antagonist .

Question 24

In the presence of picrotoxin , diazepam is less efficacious at causing sedation , regardless of the dose . Picrotoxin by it self has no sedative effect even at the highest dose . Which of the following is correct ?

A) Picrotoxin is a competitive antagonist .
B) Diazepam is a full agonist , and picrotoxin is a partial agonist.
C) Diazepam is less efficacious than is picrotoxin.
D) Diazepam is less potent than is picrotoxin .
E) Picrotoxin is a noncompetitive antagonist .

Question 25

Which of the following would up regulate postsynaptic beta 1 adrenergic receptors?
Daily use of amphetamine that causes norepinephrine to be released .

A) A disease that causes an increase in the activity of norepinephrine neurons .
B) Daily use of isoproterenol , a beta 1 receptor agonist .
C) Daily use of formoterol , a beta 2 receptor agonist.
D) E-Daily use of propranolol , a beta 1 receptor antagonist .
E) ....

Question 26

Which one of the following is a fundamental difference between competitive and noncompetitive antagonist ?

A) Competitive and non competitive work on different receptors .
B) Competitive antagonist reduces agonist potency (increase EC50) and non competitive antagonist reduces agonist efficacy (decrease E max ) .
C) There is no difference between them , they are exactly the same .
D) Non competitive antagonist causes an upward shift of the E max while competitive antagonist does the opposite .

Question 27

Which of the following regarding E max is correct ?

A) E max assumes that as long as you increase the concentration of the drug , there will be a higher effect of the drug .
B) E max is used to compare the potency of different drugs .
C) E max assumes that all receptors are occupied by the drug and no increase in response is observed if a higher concentration of drug is obtained .
D) All of the previous points are incorrect .

Question 28

Candesartan and irbesartan are angiotensin receptor blockers that are used to treat hypertension . The therapeutic dose range for candesartan is 4 to 32 mg , as compared to 75 to 300 mg for irbesartan . which of the following regarding this statement is correct ?

A) Candesartan is more potent than is irbesartan .
B) Candesartan and irbesartan have different efficacy .
C) Candesartan is a non competitive antagonist for irbesartan .
D) Irbesartan is a competitive antagonist for candesartan .

Question 29

A characteristic that distinguishes true receptors from other drug binding sites present in blood and other biological tissues is the characteristic of:

A) binding affinity.
B) reversible binding
C) C)signal transduction
D) stereoselective interaction.

Question 30

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.

Question 31

'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 therapeutic dose range of the drug..
D) The therapeutic index of the drug.

Question 32

Competitive antagonists.

A) Dissociate from receptors faster than their respective agonists
B) Alter the shape of the log dose response curve of an agonist
C) According to the rate theory have low dissociation rate constants
D) Initiate the opposite cellular response to receptor occupancy to that obtained by the agonist
E) All the above .

Question 33

A non-competitive antagonist :

A) Alters the mechanism of action of an agonist
B) Alters the potency of an agonist
C) Shifts the dose-response curve of an agonist to the right
D) Decreases the maximum response to an agonist
E) None of the above.

Question 34

The types of antagonism are:

A) Summarized.
B) Potentiated.
C) Additive.
D) Competitive.

Question 35

The term "chemical antagonism" means that:

A) two drugs combine with one another to form an inactive compound.
B) two drugs combine with one another to form a more active compound.
C) two drugs combine with one another to form a more water soluble compound.
D) two drugs combine with one another to form a more fat soluble compound.

Question 36

An agonist is substance that:

A) Interacts with the receptor without producing any effect
B) Interacts with the receptor and initiates changes in cell function, producing various effects
C) Increases concentration of another substance to produce effect
D) Interacts with plasma proteins and doesn't produce any effect

Question 37

If an agonist can produce maximal effects and has high efficacy it's called:

A) Partial agonist
B) Antagonist
C) Agonist-antagonist
D) Full agonist

Question 38

If an agonist can produce submaximal effects and has moderate efficacy it's called:

A) Partial agonist
B) Antagonist
C) Agonist-antagonist
D) Full agonist

Question 39

antagonist is a substance that:

A) Binds to the receptors and initiates changes in cell function, producing maximal effect
B) Binds to the receptors and initiates changes in cell function, producing submaximal effect
C) Interacts with plasma proteins and doesn't produce any effect
D) Binds to the receptors without directly altering their functions

Question 40

A competitive antagonist is a substance that:

A) Interacts receptors and produces submaximal effect
B) Binds to the same receptor site and progressively inhibits the agonist response
C) Binds to the nonspecific sites of tissue
D) Binds to one receptor subtype as an agonist and to another as an antagonist

Question 41

Irreversible interaction of an antagonist with a receptor is due to:

A) lonic bonds
B) Hydrogen bonds
C) Covalent bonds
D) All of the above

Question 42

Mechanisms of transmembrane signaling are the following EXCEPT:

A) Transmembrane receptors that bind and stimulate a protein tyrosine kinase
B) Gene replacement by the introduction of a therapeutic gene to correct a genetic effect
C) Ligand-gated ion channels that can be induced to open or close by binding a ligand.
D) Transmembrane receptor protein that stimulates a GTP-binding signal transducer protein (G-protein) which in turn generates an intracellular second messenger .

Question 43

Tick the second messenger of G-protein-coupled (metabotropic) receptor:

A) Adenylyl cyclase
B) Sodium ions
C) Phospholipase
D) CAMP .

Question 44

Tick the substance which changes the activity of an effector element but doesn't belong to second messengers:

A) CAMP
B) CGMP
C) G-protein
D) Calcium ions

Question 45

18. All of the following statements about efficacy and potency are true EXCEPT:

A) Efficacy is usually a more important clinical consideration than potency
B) Efficacy is the maximum effect of a drug
C) Potency is a comparative measure, refers to the different doses of two drugs that are needed to produce the same effect
D) The ED50 is a measure of drug's efficacy

Question 46

In the following, what describes absorption?

A) The tightness that drug bind to receptor
B) Irreversible transport from site of administration to the bloodstream
C) Drug leaving the blood to peripheral tissue
D) Proportional to drug concentration in plasma (First order kinetics implied)

Question 47

In the following, what describes distribution?

A) The tightness that drug bind to receptor
B) Irreversible transport from site of administration to the bloodstream
C) Drug leaving the blood to peripheral tissue
D) Proportional to drug concentration in plasma (First order kinetics implied)

Question 48

In the following, what describes affinity?

A) The tightness that drug bind to receptor
B) Irreversible transport from site of administration to the bloodstream
C) Drug leaving the blood to peripheral tissue
D) Proportional to drug concentration in plasma (First order kinetics implied)

Question 49

Which one of the following is true for a drug whose elimination from plasma shows first order kinetics?

A) Half-life is proportional to the drug concentration in plasma
B) The amount eliminated per unit of time is constant
C) A plot of drug concentration versus time is a straight line
D) The rate of elimination is proportional to the plasma concentration

Question 50

The addition of glucuronic acid to a drug?

A) Lowers its water solubility
B) Usually leads to inactivation of drug
C) Is an example of phase I reactions
D) Involves cytochrome P450

Question 51

A patient is treated with drug A, which has high affinity for albumin and is administered in amount that don't exceed the binding capacity of albumin, A second drug B also has high affinity for albumin but is administered in amounts that are 100 times the binding capacity of albumin. what happens after administering drug B?

A) Increase tissue concentration of drug A
B) Increase serum concentration of unbound drug A
C) Decrease tissue concentration of drug A
D) Decrease half-life of drug A

Question 52

A drug with half-life of 12 hours is administered Intravenously. how long will it take for the drug to reach 90% of
Its final steady state?

A) 90 hours
B) 40 hours
C) 30 hours
D) 24 hours

Question 53

The route of drug administration is determined by?

A) Water solubility of the drug
B) Ionization of the drug
C) Desirability of rapid onset of action of the drug
D) All of the above

Question 54

All of the following about passive absorption is true EXCEPT?

A) The driving force is concentration gradient
B) Doesn't involve a carrier
C) The process shows a low structural specificity
D) The process is saturable

Question 55

The following factor(s) influencing drug absorption?

A) Blood flow to the absorption area
B) Total surface area available
C) Contact time at the absorption surface
D) All of the above

Question 56

Factor(s) that influence bioavailability of drugs?

A) First-pass hepatic metabolism
B) Solubility of the drug
C) Chemical instability in GIT
D) All of the above

Question 57

The following factor(s) determine drug distribution?

A) Blood flow
B) Capillary permeability
C) Binding of drug to plasma proteins
D) All of the above

Question 58

All of the following is true about drug metabolism EXCEPT?

A) pro-drug must be metabolized to their active forms
B) First-order kinetics metabolism means constant amount of drug is metabolized per unit time
C) In zero-order kinetics metabolism. the enzyme is saturable
D) None of the above

Question 59

All of the following is true about drug metabolism EXCEPT?

A) Water soluble drugs must first be metabolized in the liver
B) Phase I reaction function to convert lipophilic molecules into lipophobic
C) Phase II reaction include conjugation with endogenous substances

Question 60

Correct statements listing characteristics of a particular route of drug administration include all of the following EXCEPT?

A) Intravenous administration provides a rapid response
B) Intramuscular administration requires a sterile technique
C) Inhalation provides slow access to the general circulation
D) Subcutaneous administration may cause local irritation

Question 61

Metabolic transformation (Phase I) is?

A) Acetylation and methylation of substances
B) Transformation of substances due to oxidation, reduction or hydrolysis
C) Glucuronide formation
D) Binding to plasma protein

Question 62

Which of the following is not a conjugation of a drug?

A) Glucuronidation
B) Sulfate formation
C) Hydrolysis
D) Methylation

Question 63

Metabolic (Phase I and Phase II) reactions usually result in increase of substance biological activity?

Question 64

All of the following statements related to the binding of drugs by plasma proteins are correct EXCEPT?

A) Bound drug is unable to diffuse into tissue until it becomes unbound
B) Displacement of the bound drug by another drug can increase the effects of a given dosage of the first drug
C) Bound drug is the pharmacologically active part of the drug
D) None of the above

Question 65

Binding of a drug to plasma proteins will tend to?

A) Decrease half-life
B) Decrease rate of glomerular filtration
C) Increase its rate of biotransformation
D) Increase its concentration in plasma

Question 66

Pharmacodynamics involves?

A) Info about main mechanisms of drug absorption
B) Info about unwanted effects
C) Info about biological barriers
D) Info about excretion of a drug from the organism

Question 67

Proteins which a drug molecule bind are?

A) Receptors
B) Ion channels
C) Carriers
D) All of the above

Question 68

If an agonist can produce maximal effect and has high efficacy it's called?

A) Partial agonist
B) Antagonist
C) Agonist-Antagonist
D) Full Agonist

Question 69

Irreversible interaction of an antagonist with a receptor is due to?

A) Ionic bonds
B) Hydrogen bonds
C) Covalent bonds
D) All of the above

Question 70

In the previous question, the antagonist represents?

A) Competitive antagonism
B) Noncompetitive antagonism

Question 71

Tick the substances whose mechanisms are based on interaction with ion channels?

A) Sodium channel blockers
B) Calcium channel blockers
C) Potassium channel activators
D) All of the above

Question 72

What term is used to describe a more gradual decrease in responsiveness to a drug, taking weeks or months or years to develop?

A) Refractoriness
B) Cumulative effect
C) Tolerance
D) Tachyphylaxis

Question 73

If two drugs with the same effect, taken together, produce an effect equal in magnitude to the sum of their effects given individually. It's called?

A) Antagonism
B) Synergism
C) additive drug effect
D) None of the above

Question 74

Chemical antagonism means?

A) Two drugs combine with one another to form an inactive compound
B) Two drugs combine with one another to form a more active compound
C) Two drugs acting competitively on the same receptor
D) Two drugs acting on different receptors with opposite effects at the same time

Question 75

If 87.5% of a drug is eliminated via first order kinetics in 15 hours. Half-life of this drug is expected to be?

A) 5 hours
B) 10 hours
C) 15 hours
D) 30 hours

Question 76

A pharmacological response might be reduced by all of the following EXCEPT?

A) Low solubility of drug
B) Abnormal target receptors
C) Lack of absorption at site of administration
D) Interference with drug elimination

Question 77

The oral route of drug administration tends to be associated with all of the following EXCEPT?

A) Relative safety
B) Rapid response
C) Convenience
D) Incomplete absorption

Question 78

Therapeutic index of a drug reflects its?

A) Relative safety
B) Duration of action
C) Onset effects
D) Potency

Question 79

Which of the following is CORRECT?

A) Value of t (1/2) depends on rate of absorption
B) Increase in Kd of drug with plasma protein is associated with increase in T (1/2)
C) T (1/2) value is required for dose estimation
D) Drugs associated with short T (1/2) are characterized by low systemic clearance.

Question 80

Which of the following statements about drug receptor interactions is TRUE?

A) An agonist interacts with its target receptors and produces a biological effect
B) A reversible antagonist shifts the dose response curve to the right without affecting the maximal response
C) Partial agonist are drugs that have affinity for receptors with moderate efficacy
D) All of the above