Choose the most appropriate answer. Each multiple choice question is worth 2 points.

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DAPH 721 - Pharmacology

Dr. Gail Galasko August 24, 2004 Test 1B

Choose the most appropriate answer. Each multiple choice question is worth 2 points.

1. Each of the following is true regarding drug biotransformation except one. a. the rate may differ significantly in various animal species.

b. It primarily occurs in the liver microsomal enzyme system. c. It usually converts a drug to its lipid-soluble, nonionized form.

d. It generally involves alterations of the chemical structure of the drug 2. The major effect of a drug is produced by the amount of the drug that is

a. free in plasma

b. excreted by the kidney c. detoxified in the liver d. bound to plasma protein

3. The onset of action of a drug is primarily determined by the rate of

a. excretion

b. absorption

c. distribution

d. biotransformation

4. The Therapeutic Index ( T.I.) of a drug is defined as:

a. ED50/LD50

b. ED1/LD99

c. LD1/ED99

d. LD99/ED1

e. LD50/ED50

5. The maximal or “ceiling” effect of a drug is also correctly referred to as the drug’s

a. agonism

b. potency

c. efficacy

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of patients; the percentages of the population showing therapeutic and toxic effects were graphed. Based on

the graph, it may be concluded that: a. Drug A is safer than drug B.

b. Drug B is less effective than drug A. c. The two drugs act on the same receptors. d. The therapeutic index of drug A is 10. e. The therapeutic index of drug B is 10.

100 Drug B Toxic Drug A Toxic Drug B Therapeutic Drug A Therapeutic 50 % of Population Responding 0.1 10 100 1000 Log Dose

7. Two drugs, A and B, have the same mechanism of action. Drug A in a dose of 5 mg produces the same magnitude of effect as drug B in a dose of 500 mg. a. Drug B is less efficacious than drug A.

b. Drug A is about 100 times more potent than drug B. c. Toxicity of drug A is less than that of drug B.

d. Drug A is a better drug if maximal efficacy is needed.

e. Drug A will have a shorter duration of action than drug B because less of drug A is present.

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Amount of Effect Y Y + 100 nM Z 0.1 1.0 10 Y + 50 nM Z X

Log Dose X or Y (uM) 8. Refer to the diagram above:

a. Drug Z is a competitive antagonist of drug Y. b. Drug Z is a competitive antagonist of drug X. c. Drug Z is a non-competitive antagonist of drug Y. d. Drug Y is a competitive antagonist of drug X.

e. A mixture of 0.1 nM X + 1.0 nM Y would be more effective than 0.1 nM X by itself.

9. Refer to the diagram above:

a. Drug X is more efficacious than drug Y. b. Drug X is more potent than drug Y.

c. Drug Y has lower therapeutic index than drug X. d. all of the above.

e. (a) and (b)

10. 500 mg of a drug is give I.V. After 10 hours the plasma concentration of the drug is 125 mg. What is the half-life (t1/2) of the drug?

a. 10 hours

b. 7 hours

c. 5 hours

d. 2 hours

e. cannot be calculated from the data given

11. Which of the following strategies would result in reduced first-pass hepatic metabolism of a drug compared to oral administration?

a. The use of timed-release preparation. b. Sublingual administration

c. The use of enteric coated tablets. d. IV administration

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receptor interaction EXCEPT

a. the affinity of a drug is dependent on its intrinsic activity.

b. the maximum effect of a drug occurs when all receptors are occupied. c. an antagonist may have affinity for the receptor but no intrinsic activity. d. the magnitude of the effect of a drug is proportional to the number of

receptors occupied.

e. it follows the law of mass action.

13. If drug A has a greater efficacy than drug B, then drug A a. is more toxic than drug B.

b. has a greater affinity for the receptor than drug B. c. has a greater margin of safety than drug B.

d. is capable of producing a greater maximum effect than drug B. e. all of the above

14. The therapeutic index of a drug is the ratio of a. the effective dose to the toxic dose.

b. half the toxic dose to half the effective dose.

c. the maximum tolerated dose to the minimum effective dose. d. the lethal dose for 50% of animals to the effective dose for 50% of

animals.

e. none of the above

15. Which of the following types of chemical bonding is the least likely to be involved in a drug-receptor interaction?

a. covalent bonding b. hydrogen bonding c. dipole-dipole bonding d. electrostatic bonding e. van der Waal's forces

16. Competitive inhibitors of enzymes and hormone receptors share all of the following characteristics EXCEPT

a. usually combine reversibly with their macromolecular targets. b. stereoisomers may have markedly different potencies.

c. pharmacological effects can ALWAYS be reversed by supplying the endogenous substrate or agonist, respectively.

d. only a limited number of related chemicals are active. e. can display marked selectivity between species.

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17. The metabolism of drugs

a. usually results in compounds with increased hydrophobicity.

b. is vitally important for the elimination of very hydrophilic compounds. c. is often carried out in the smooth ER of the liver.

d. is generally most rapid at the extremes of life. e. occurs exclusively in the liver.

18. A drug with a LD1/ED100 equal to 10 would be considered a. fat soluble.

b. long acting. c. highly protein bound. d. safe to take.

e. all apply

19. A drug has an LD50 of 10g and ED50 of 10 mg. Which of the following is true? a. The therapeutic index is high, so the drug is relatively safe.

b. The therapeutic index is high, so the drug is relatively dangerous. c. The therapeutic index is low, so the drug is relatively safe.

d. The therapeutic index is low, so the drug is relatively dangerous. 20. Which of the following terms describes a drug that blocks an agonist at its

receptors by occupying them without activating them? a. competitive antagonist

b. partial agonist

c. physiological antagonist d. chemical antagonist

e. non-competitive antagonist

21. The intravenous administration of 1 gm of an antibiotic to ten 70-kg patients resulted in an average plasma concentration of 57 ug/ml ten minutes after the injection. The apparent volume of distribution of this drug is approximately

a. 175 L.

b. 0.06 L.

c. 0.25 L/kg.

d. 5.7 L/kg.

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a. produce a lower maximal response than do full agonists.

b. are metabolized more rapidly than full agonists thus reducing their effective concentration in the biophase.

c. produce greater than additive effects in the presence of full agonists. d. all of the above

e. (a) and (b)

23. Distribution of drugs to specific tissues

a. is independent of blood flow to the organ.

b. is independent of the solubility of the drug in that tissue.

c. depends on the unbound drug concentration gradient between blood and the tissue.

d. is increased for drugs that are strongly bound to plasma proteins. e. has no effect on the half-life of the drug.

24. Aspirin is a weak organic acid with a pKa of 3.5. What percentage of a given

dose will be in the lipid-soluble form at a stomach pH of 2.5?

a. About 1%

b. About 10%

c. About 50%

d. About 90%

e. About 99%

25. Which of the following provides information about the therapeutic index of a drug?

a. Efficacy or Therapeutic Efficacy

b. Drug Potency

c. Graded Dose Response Curve d. Quantal Dose Response Curve e. None of the above

26. Which of the following provides information about both the potency and efficacy of a drug?

a. Efficacy or Therapeutic Efficacy b. Therapeutic Index

c. Drug Potency

d. Graded Dose Response Curve e. Quantal Dose Response Curve

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27. Which of the following terms refers to the antagonism of leukotriene's bronchoconstrictor effect (mediated by leukotriene receptors) by terbutaline (acting at adrenergic receptors) in a patient with asthma?

a. Competitive Antagonist b. Partial Agonist

c. Physiological Antagonist d. Chemical Antagonist

e. Non-competitive Antagonist

28. Which of the following terms refers to an antagonist that interacts directly with the agonist and not with the receptor?

a. Competitive Antagonist b. Partial Agonist

c. Physiological Antagonist d. Chemical Antagonist

e. Non-competitive Antagonist

29. When tubular urine is made more acidic, weak bases are excreted more rapidly because weak bases are more ionized at acidic pH.

a. Both statements are true and related. b. Both statements are true but not related.

c. The first statement is true. The second statement is false. d. The first statement is false. The second statement is true. e. Both statements are false.

30. When tubular urine is made more acidic, weak acids are excreted more rapidly because weak acids are more ionized at acidic pH.

a. Both statements are true and related. b. Both statements are true but not related.

c. The first statement is true. The second statement is false. d. The first statement is false. The second statement is true. e. Both statements are false.

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Amount of Effect 100 0.1 1.0 A + 25 nM of C A + 10 nM of C B A Log Dose

31. Refer to the diagram above:

a. Drug C is a noncompetitive antagonist of drug A. b. Drug C is a competitive antagonist of drug A. c. Drug C is a noncompetitive antagonist of drug B. d. Drug C is a competitive antagonist of drug B. e. None of the above

Y X Amount of Effect Log Dose

32. Refer to the diagram above:

a. Drug X is more efficacious than drug Y. b. Drug X is more potent than drug Y.

c. Drug Y has lower therapeutic index than drug X. d. (a) and (b)

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33. A drug with an elimination half-life (t1/2) of 16 hours is given orally 3 times a day.

Each dose is 100 mg. When administration is stopped, how long will it take for at least 95% of the drug in the body to be eliminated?

a. 1 day

b. 3 days

c. 5 days

d. 1 week

e. 1 month

34. A drug has a half-life of 4 hours. If 2 grams of the drug are given every 4 hours, what will be the amount in grams in the body immediately after the third dose?

a. 1.5

b. 2.0

c. 3.5

d. 4.0

e. 6.0

35. At a pH of 7.8, lidocaine (pKa = 7.8) will exist in

a. the ionized form.

b. equal amounts of ionized and unionized forms c. the non-ionized form.

d. a mixture containing 10 times more ionized than non-ionized forms. e. none of the above

36. Regarding termination of action,

a. drugs must be excreted from the body to terminate their action. b. metabolism of drugs always increases their water solubility.

c. metabolism of drugs always abolishes their pharmacologic activity. d. hepatic metabolism and renal excretion are the two most important

mechanisms involved.

Figure

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References

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