Pharmacology Test 1A

Front 1

Phase I drug metabolic reactions include all of the following EXCEPT
A.drug reduction reactions.
B.drug hydrolysis reactions.
C.cytochrome P450-catalyzed oxidations.
D.acetylation reactions.
E. non cytochrome P450-catalyzed oxidations.

Back 1

Acetylation Reactions

Front 2

The following are all true about Cytochrome P450 reactions EXCEPT that they
A.are inducible.
B.utilize ATP as a substrate.
C.may expose a hydroxyl group.
D.can be used to convert prodrugs into active drugs.
E.can be inhibited by isoniazid

Back 2

Utilize ATP as a substrate

Front 3

Which of the following may act as inducers of cytochromes P450?
A.Ethanol
B.Cigarette smoke
C.Phenytoin
D.All of the above
E.None of the above

Back 3

All of the above

Front 4

Formation of acetaminophen glucuronide is described by each of the following EXCEPT
A.phase II conjugation reaction.
B.glucose and UTP are precursors.
C.catalyzed by a transferase enzyme.
D.glutathione adduct.
E.water soluble metabolite.

Back 4

Glutathione Adduct

Front 5

Phase II (Type II) metabolic reactions conjugate drugs with all the following EXCEPT
A.acetate
B.glycine
C.glucuronide
D.nitrate
E.sulfate

Back 5

Nitrate

Front 6

The following activities are associated with hepatic drug metabolism EXCEPT
A.drug detoxification
B.prodrug activation
C.formation of toxic drug metabolites
D.decreased VD

Back 6

Decreased VD

Front 7

40. Drug Y is completely absorbed, Foral = 1.0, and hepatic clearance = 2 ml hr-1 kg-1. It is being administered chronically. Drug Z, a known inhib¬itor of the liver metabolism of Drug Y, is added. At steady state, which of the following observations would be consistent with this drug interaction?
A.Decreased Foral of Drug Y
B.Decreased pharmacodynamic effect of Drug Y
C.Decreased VD of Drug Y
D.Increased Cl of Drug Y
E.Increased T1/2 of Drug Y

Back 7

Increased T1/2 of Drug Y

Front 8

Induction of drug metabolism may result in all of the following EXCEPT
A.decreased half-life of elimination.
B.decreased oral bioavailability.
C.increased toxicity.
D.change in conformation of the receptor that a drug binds to.

Back 8

change in conformation of the receptor that a drug binds to

Front 9

Each of the following statements is consistent with mutual competitive inhibition of drug metabolism by two drugs EXCEPT
A.both drugs are being metabolized near their Vmax rates.
B.both drugs are metabolized by the same enzyme.
C.the concentrations of both drugs are below their Km values.
D.the two drugs are being administered simultaneously.
E.the two drugs have dissimilar structures.

Back 9

the concentrations of both drugs are below their Km values

Front 10

Which of the following properties of the anticonvulsant drug carbamazepine make it a potential inducer of the metabolic enzymes of the liver endoplasmic reticulum?
A.Binding to serum albumin.
B.Low lipid solubility of non-ionized form.
C.Tendency to accumulate in fat.
D.Tendency to accumulate in the kidney.
E.Use for therapy of a chronic disease.

Back 10

E

Front 11

Hepatic blood flow and intrinsic hepatic clearance are important factors in the clearance of drugs with which of the following characteristics?
A.Very water soluble
B.Polypeptide structure
C.Multiple charges
D.Volatile gas
E.Minimal renal excretion

Back 11

Minimal Renal Excretion

Front 12

Both N-acetyltransferase and cytochrome P-450 enzymes display genetic polymorphism with re¬spect to drug metabolism. Which of the following applies to people that are affected by one of these poly¬morphisms?
A.Rapid metabolizers are more prone to drug interactions involving the parent drug.
B.Rapid metabolizers are not prone to drug interactions involving the metabolite of the drug.
C.Slow metabolizers are more prone to adverse reactions involving the parent drug.
D.Slow metabolizers are more prone to drug interactions involving the metabolite of the drug.
E.Slow metabolizers have a shorter duration of action with a single dose of drug.

Back 12

Slow metabolizers are more prone to adverse reactions involving the parent drug.

Front 13

The two-step reaction pictured below is best characterized by which of the following?
Codeine  Morphine  Morphine-O-sulfate

A.Formation of a water soluble metabolite.
B.Metabolic drug activation.
C.Both A and B
D.Neither A nor B

Back 13

Both A & B

Front 14

Two drugs, A and B, have the same mechanism of action. Drug A in a dose of 5 mg produces the same magnitude of response as Drug B in a dose of 500 mg. Which of the following statements is CORRECT?
A.Drug A is less toxic.
B.Drug A is more efficacious.
C.Drug A is more potent.
D.Drug A has a shorter duration of action.
E.Drug A is a better drug to use when a maximal response is desired.

Back 14

Drug A is more potent

Front 15

Each of the following statements regarding drug action and/or drug toxicity is correct EXCEPT
A.for some drugs, even very minimal concentrations can be toxic.
B.most drugs exert a single action.
C.toxicity is both time- and dose dependent.
D.toxicity can be due to over-dosage of a drug.
E.symptoms of toxicity can be anything ranging from nausea to death.

Back 15

Most drugs exert a single action

Front 16

A pharmacologic agonist is a chemical substance that
A.binds to a specific receptor and initiates a response.
B.typically elicits a pharmacologic response without binding to a specific receptor.
C.exhibits no activity except to oppose the effect of an antagonist.
D.binds to a specific receptor but does not initiate a response

Back 16

Binds to a specific receptor and initiates a response

Front 17

Which of the following statements best describes the toxicity of most drugs?
A.Toxicity is unrelated to dose.
B.Toxicity is unpredictable and random.
C.Toxicity and therapeutic effects always arise from different mechanisms.
D.Toxicity is not produced at the recommended dose listed in the ADA Guide to Dental Therapeutics
E.Toxicity is often an extension of the desired drug effect.

Back 17

Toxicity is often an extension of the desired drug effect

Front 18

Compared to its density (number per cell) at the resting state, the density of an alpha-adrenergic receptor on vascular smooth muscle will likely be increased during chronic administration of a/an
A.partial antagonist.
B.agonist.
C.antagonist.
D.partial agonist.

Back 18

Antagonist

Front 19

Which of the following statements concerning a drug's properties is CORRECT?
A.An antagonist can block the action of a partial agonist but not the action of a full agonist.
B.A partial agonist has greater potency than an antagonist.
C.An antagonist has less potency than an agonist.
D.The effects of a competitive antagonist are reversible.
E.The effects of a non-competitive antagonist are reversible.

Back 19

The effects of a competitive antagonist are reversible

Front 20

Which of the following is the LEAST important property of a drug?
A.Bioavailability
B.Clearance
C.Half-life
D.Potency
E.Volume of distribution

Back 20

Potency

Front 21

The therapeutic index of a drug
A.determines the VD of the drug.
B.determines the T1/2 of the drug.
C.measures the ratio of the clearances of the drug’s primary metabolite versus the parent drug.
D.measures the drug dose necessary to achieve the minimal therapeutic concentration.
E.measures the ratio of the drug dose causing toxicity versus that giving a therapeutic effect.

Back 21

measures the ratio of the drug dose causing toxicity versus that giving a therapeutic effect.

Front 22

All of the following statements regarding Drugs A/B/C/D could be correct EXCEPT
A.response B is caused by a different drug than Responses A/C/D.
B.response B is caused by a partial antagonist.
C.response C is caused by a different drug than Response A.
D.assume Drug X gives Response A. Response C shows the effect elicited by Drug X after the addition of a competitive antagonist.
E.assume Drug X gives Response A. Response D shows the effect elicited by Drug X after the addition of a non-competitive antagonist.

Back 22

assume Drug X gives Response A. Response D shows the effect elicited by Drug X after the addition of a non-competitive antagonist.

Front 23

Assuming each curve represents the response to a different drug, which of the drugs is LEAST efficacious?
A.Drug A
B.Drug B
C.Drug C
D.Drug D

Back 23

Drug B

Front 24

The "Log Dose-Response Curve" for drug action obeys the Law of Mass Action. The following statements about this relationship are all correct EXCEPT
A.drug concentration is varied.
B.total receptor concentration remains constant.
C."effect" is proportional to the concentration of the 'drug-receptor' complex.
D."effect" may refer to the range of a physiological response within a group of individuals to a given dose of drug.
E."effect" may refer to either a toxic or a therapeutic action of the drug.

Back 24

"effect" may refer to the range of a physiological response within a group of individuals to a given dose of drug.

Front 25

Classification of hormone and neurotransmitter receptors is predominately by measurement of the
A.intracellular second messenger generated by receptor activation.
B.maximal effect of a series of agonists and antagonists.
C.rank order of potency of a series of agonists and antagonists.
D.therapeutic index for a series of agonists and antagonists.
E.tissue distribution of the receptor in question.

Back 25

rank order of potency of a series of agonists and antagonists

Front 26

If R is the resting, inactive state of a receptor and R* is the activated state of that same receptor, which of the following is a correct statement concerning the properties of drugs that bind at that receptor?
A.An agonist always has greater affinity for R* than for R.
B.An antagonist always has greater affinity for R* than for R.
C.A noncompetitive antagonist always has equal affinity for R* and R.
D.An partial antagonist always has equal affinity for R* than for R.
E.A partial agonist always has equal affinity for R* and R.

Back 26

An agonist always has greater affinity for R* than for R.

Front 27

The oral loading dose required to produce an initial concentration of 9.0 g/ml is
A.300 mg
B.600 mg
C.900 mg
D.1200 mg
E.1500 mg

Back 27

900 mg
(75,000mL*9ug/mL) / 0.75

Front 28

The intravenous maintenance dose required to sustain a concentration of 8.0 ug/ml is
A.0.60 mg/min
B.1.2 mg/min
C.2.4 mg/min
D.3.6 mg/min
E.6.0 mg/min

Back 28

6.0mg/min

Front 29

The half-life of X is
A.6.93 min
B.50 min
C.69.3 min
D.500 min
E.693 min

Back 29

69.3 min
T1/2 = (0.693*Vd) / (Cl) = min = hours

T1/2 = 0.693*75000ml / 750ml/min = 69.3 min

Front 30

If an infusion of X is begun and no loading dose is given, at 5.0 hours the plasma concentration will be
A.less than 25% of the steady state concentration.
B.between 25 and 50% of the steady state concentration.
C.50% of the steady state concentration.
D.between 50 and 75% of the steady state concentration.
E.greater than 75% of the steady state concentration.

Back 30

Greater than 75% of the steady state concentration

Front 31

The oral loading dose required to produce an initial concentration of 3 ug/ml is approximately
A.1.1
B.1.5 gm
C.1.9 gm
D.2.3 gm
E.4.5 gm

Back 31

1.9 gm

Front 32

What is the approximate T1/2 of X?
A. 6.9 hr
B. 7.5 hr
C. 15 hr
D. 21.6 hr
E. 30

Back 32

15 hr

Front 33

If X were infused intravenously at a rate of 1.9 mg/min, the steady state plasma concentration, calculated assuming first order kinetics, would be approximately
A. 1 ug/ml
B. 3 ug/ml
C. 5 ug/ml
D. 7 ug/ml
E. 10 ug/ml

Back 33

5 ug/ml

Front 34

The half-life for a drug might be altered by all of the following EXCEPT
A.Increasing the volume of distribution
B.Changing the renal clearance
C.Changing the total clearance
D.Decreasing the volume of distribution
E.Increasing the maintenance dose

Back 34

Increasing the maintenance dose

Front 35

.

Back 35

A
T1/2 = 0.693*Vd / Cl

Front 36

Which of the following statements concerning pharmacokinetics is CORRECT?
A.Elimination of most drugs follows first order kinetics.
B.Steady state drug concentration is dependent on VD.
C.Loading dose is dependent primarily on Cl.
D.The rate of absorption of a drug is dependent on its Cl.
E.The T1/2 for elimination of a drug is directly dependent on Cl.

Back 36

Elimination of most drugs follows first order kinetics.

Front 37

The steady-state plasma concentration of lidocaine being administered continuously as a intravenous infusion is increased by congestive heart failure due to which of the following changes?
A.Decreased distribution to fat
B.Decreased hepatic blood flow
C.Increased plasma protein binding
D.Decreased renal blood flow
E.Increased binding to tissues

Back 37

Decreased Hepatic Blood Flow

Front 38

Which of the following properties of a drug is NOT dose/concentration-dependent.
A.Toxicity
B.Binding to plasma protein
C.Metabolism
D.Receptor binding
E.T1/2

Back 38

T1/2

Front 39

Given equivalent doses of drugs A and B: upon distribution, A is confined essentially to the plasma whereas B is highly sequestered in muscle. Both are cleared primarily via glomerular filtration. Which of the following relationships apply to A versus B (in that order)?
A.Long versus short T1/2.
B.Low versus high lipid solubility.
C.Low versus high plasma concentration.
D.Short versus long duration of action.
E.Small versus large volume of distribution.

Back 39

Small versus large volume of distribution

Front 40

A drug with a VD of 500 L most likely
A.distributes primarily into the extracellular fluid space.
B.distributes primarily into muscle and/or fat.
C.is distributed primarily in the blood.
D.probably undergoes extensive first pass metabolism.

Back 40

Distributes Primarily into muscle and/or fat

Front 41

Drugs R and S are being administered simultaneously. Both depend on CYP2D6 for their elimination. Drug R has a plasma concentration equal to 0.1X its Km for CYP2D6. Drug S has a plasma concentration equal to 10X its Km for CYP2D6. Which of the following best describes the consequence of this situation?
A.The metabolism of Drug R is nearly normal
B.The metabolism of Drug S is about 90% inhibited.
C.The metabolism of Drug S is enhanced.
D.The metabolism of Drug R is about 90% inhibited.
E.The metabolism of Drug R and Drug S is inhibited to the same extent.

Back 41

The metabolism of Drug R is about 90% inhibited.

Front 42

A drug with a VD of 40 L most likely
A.distributes primarily into the central nervous system.
B.distributes primarily into the plasma.
C.is probably evenly distributed throughout total body water.
D.is probably eliminated very rapidly.
E.probably undergoes extensive first pass metabolism.

Back 42

is probably evenly distributed throughout total body water.

Front 43

A drug has a very short T1/2. Which of the following is most compatible with this short T1/2?
A.A small VD
B.Minimal first pass metabolism
C.Extensive reabsorption by the kidney
D.Extensive induction of metabolic degradative enzymes.
E.Poor bioavailability

Back 43

A small VD

Front 44

Which of the following is the most important factor in determining the absorption of a drug?
A.Concentration of drug in intestine
B.Diffusion coefficient
C.pH of the small intestine
D.pKa
E.Oil:water partition coefficient

Back 44

Oil:water partition coefficient

Front 45

The rate of gastrointestinal absorption of a drug is generally dependent on all of the following factors EXCEPT
A.intestinal surface area.
B.the oil:water partition coefficient of the drug.
C.the pKa of the drug.
D.the rate of stomach emptying.
E.stomach surface area.

Back 45

Stomach Surface Area

Front 46

An uncharged drug that is neither a weak organic acid nor a weak organic base and is soluble in both aqueous and lipid environments is likely to be characterized by
A.a VD similar to total body water.
B.accumulation in the CNS.
C.high affinity binding to plasma albumin.
D.limited oral bioavailability.
E.very high reabsorption from the renal tubules.

Back 46

a VD similar to total body water.

Front 47

The rate of absorption of a drug will determine
A.steady-state plasma concentration.
B.systemic clearance.
C.bioavailability.
D.peak plasma concentration.
E.intrinsic clearance.

Back 47

peak plasma concentration

Front 48

Which of the following properties of a drug is most closely associated with its ability to cross the "blood brain barrier"?
A.Binding to plasma protein
B.Capillary permeability
C.Lipid solubility
D.Positive charge
E.Small size

Back 48

Lipid solubility

Front 49

Which of the following is a correct statement concerning pharmacokinetic or pharmacodynamic parameters?
A.Cl is the constant fraction of drug cleared per unit time.
B.Foral is the fractional rate of drug absorption from the small intestine.
C.The “slope” of a dose response curve is a measure of the rate of that drug’s onset of action.
D.Steady state concentration of a chronically administered drug is dependent on VD.
E.VD is the physical fluid volume in the body into which a drug is distributed.

Back 49

Cl is the constant fraction of drug cleared per unit time

Foral is the bioavailability. Fraction of amount of drug reaching circulation / amount of drug administered. It is the extent to which a drug reaches its site of action.

Front 50

A drug that is highly charged and water soluble is likely to dis¬play which of the following characteristics?
A.A large volume of distribution (VD)
B.A low clearance (Cl)
C.Easy access to the central nervous system
D.Extensive hepatic metabolism
E.Limited oral bioavailability (F oral)

Back 50

Limited oral bioavailability (F oral)

Front 51

A patient is taking phenytoin, a drug used in the treatment of seizure disorders, and has not had a seizure in 2 months and had a serum phenytoin concentration of 10 mg/liter last week. We know that phenytoin is 90% bound to plasma albumin, has an apparent volume of distribution of 0.7 liters/kg and is eliminated by hepatic metabolism. Because of an infection you prescribe Drug X. Drug X is known to increase hepatic microsomal P450 mediated hydroxylation activity Four days after beginning Drug X the patient has a seizure and is brought to the emergency room where you see him. When you compare phenytoin now to before starting Drug X you expect which of the following?
A.The apparent volume of distribution will be increased.
B.The plasma concentration of total phenytoin will be lower.
C.The protein-binding of phenytoin will be decreased.
D.The renal clearance of phenytoin will be increased.
E.The systemic clearance of phenytoin will be decreased.

Back 51

plasma concentration of total phenytoin will be lower.

Front 52

All of the following statements about proximal renal tubular secretion of organic cations like TEA+ (tetraethylammonium) are correct EXCEPT
A.the brush basolateral membrane is more permeable to TEA+ than the brush border (lumenal) membrane.
B.the Na+/H+ antiporter plays a role in TEA+ transport across the brush border membrane.
C.the pH gradient favors uptake by passive non-ionic diffusion at basolateral membrane.
D.uptake at the basolateral membrane is carrier-mediated.
E.uptake at the basolateral membrane is coupled to intracellular energy.

Back 52

the brush basolateral membrane is more permeable to TEA+ than the brush border (lumenal) membrane.

Front 53

Which drug is most likely to undergo competition for intestinal absorption after oral intake?
A.A glucose analog
B.A lipophilic weak organic base, pKa 11
C.A hydrophilic weak organic acid, pKa 4
D.A quaternary nitrogen compound
E.A lipophilic weak organic acid, pKa 1.5

Back 53

A glucose analog

Front 54

Dog A is injected intramuscularly with a large dose of morphine. The dog is then placed into a cage with Dog B. Upon returning some hours later to check on Dog A, you observe that Dog B is clearly morphine intoxicated. Which of the following statements concerning morphine would help explain why Dog B is morphine intoxicated?
A.Morphine is a weak organic acid that causes constipation.
B.Morphine is a weak organic base that causes emesis.
C.Morphine is a weak organic acid that is well absorbed in the stomach.
D.Morphine causes sedation and euphoria.
E.Morphine is volatile, and its primary route of elimination is via the lungs.

Back 54

Morphine is a weak organic base that causes emesis.