pharmacology questions

1.Which one of the following statements is CORRECT?

Weak bases are absorbed efficiently across the epithelial cells of the stomach.

Coadministration of atropine speeds the absorption of a second drug.

Drugs showing large VD can be efficiently removed by dialysis of the plasma.

Stressful emotions can lead to a slowing of drug absorption.

If the VD for a drug is small, most of the drug is in the extraplasmic space.

2. Which one of the following is TRUE for a drug whose elimination from plasma shows first-order kinetics?

The half-life of the drug is proportional to the drug concentration in plasma.

The rate of elimination is proportional to the plasma concentration.

The amount eliminated per unit time is constant.

Elimination involves a rate-limiting enzymic reaction operating at its maximal velocity (Vmax).

A plot of drug concentration versus time is a straight line.

3. all of the following statements are true EXCEPT:

Aspirin (pKa = 3.5) is 90% in its lipid-soluble, protonated form pH = 2.5.

The basic drug promethazine (pKa = 9.1) is more ionized at pH = 7.4 than at pH = 2.

Absorption of a weakly basic drug is likely to occur faster from the intestine than from the stomach.

Acidification of the urine accelerates the secretion of a weak base, pKa = 8.

Uncharged molecules more readily cross cell membranes than charged molecules.

4. A patient is treated with drug A, which has a high affinity for albumin and is administered in amounts that do not exceed the binding capacity of albumin. A second drug, B, is added to the treatment regimen. Drug B Also has a high affinity for albumin but is administered in amounts that are 100 times the binding capacity of albumin. Which of the following occurs after administration of drug B?

An increase in the tissue concentrations of drug A.

A decrease in the tissue concentrations of drug A.

A decrease in the volume of distribution of drug A.

A decrease in the half-life of drug A.

Addition of more drug A significantly alters the serum concentration of unbound drug B.

5. The addition of glucuronic acid to a drug

decreases its water solubility.

usually leads to inactivation of the drug.

is an example of a Phase I reaction.

occurs at the same rate in adults and the newborn.

involves cytochrome P-450.

6. Drugs showing zero-order kinetics of elimination

are more common that those showing first order kinetics.

decrease in concentration exponentially with time.

have a half-life independent of dose.

show a plot of drug concentration versus time that is linear.

show a constant fraction of the drug eliminated per unit time.

7. a drug, given as a 100 mg single dose, results in a peak plasma concentration of 20 ug/ml. The apparent volume of distribution is (assume a rapid distribution and negligible elimination prior to measuring the peak plasma level :

0.5 L.

1L

2L

3L

4L

8. A drug with a half-life of 12 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach 90% of its final steady-state level?

18 hours.

24 hours.

30 hours.

40 hours.

90 hours.

9. Which of the following results in a doubling of the steady-state concentration of a drug?

Doubling the rate of infusion.

Maintaining the infusion rate, but doubling the loading dose.

Doubling the rate of infusion and doubling the concentration of the infused drug.

Tripling the rate of infusion.

Quadrupling the rate of infusion.

10. Which of the following statements is correct?

if 10 mg of drug A produces the same response as 100 mg of drug B, drug A is more efficacious than drug B.

The greater the efficacy, the greater the potency of a drug.

In selecting a drug, potency is usually more important than efficacy.

A competitive antagonist increases ED5o.

Variation in response to a drug among different individuals is most likely to occur with a drug showing a large therapeutic index.

11. Which of the following most closely describes the clearance rate of a drug that is infused at a rate of 4 mg/min and produces a steady-state concentration of 6 mg/L in the plasma?

67 ml/min.

132 ml/min.

300 ml/min.

667 ml min.

1,200 ml/min.

12. The antimicrobial drug, tetracycline, is found to be therapeutically effective when 250 mg of drug are present in the body. The t1/2 of tetracycline is 8 hours. What is the correct rate of infusion?

7 mg/hr.

12 mg/hr.

22 mg/hr.

37 mg/hr.

45 mg/hr.

13. A drug, given as a 100-mg single dose, results in a peak plasma concentration of 20 μg/mL. The apparent volume of distribution is (assume a rapid distribution and negligible elimination prior to measuring the peak plasma level)

0.5 L.

1L

2L

5L

10L

14. A drug with a half-life of 12 hours is administered by continuous intravenous infusion. How long will it take for the drug to reach 90 percent of its final SteadyState level?

18 hours.

24 hours.

30 hours.

40 hours.

90 hours.

15. A heart failure patient shows digoxin toxicity. She received 125 mcg as standard dose. Serum levels were reported to be 2 ng /mL (2 mcg/L). Target therapeutic level is 0.8 ng/mL. What dose should she receive?

25 mcg.

50 mcg.

75 mcg.

100 mcg.

125 mcg.

16. Drug X produces maximal contraction of cardiac muscle in a manner similar to epinephrine. Drug X is considered to be a (n)

Agonist.

Partial agonist.

Competitive Antagonist.

Irreversible antagonist.

Inverse agonist.

17. Variation in the sensitivity of a population of individuals to increasing doses of a drug is best determined by which of the following?

Efficacy.

Potency.

Therapeutic index.

Graded dose–response curve.

Quantal dose–response curve.

18. Which of the following statements most accurately describes a system having spare receptors?

The number of spare receptors determines the maximum effect.

Spare receptors are sequestered in the cytosol.

A single drug–receptor interaction results in many cellular response elements being activated.

Spare receptors are active even in the absence of agonist.

Agonist affinity for spare receptors is less than their affinity for nonspare receptors.

19. Receptors are macromolecules that

Are designed to attract drugs

Are resistant to antagonists

Exist as targets for physiological neurotransmitters and hormones

Are only on the outer surface of cells

20. The primary consideration in all clinical trials is to

Determine the safety of the drug

Determine the efficacy of the drug

Ensure that there is no risk to the subject

Provide for the welfare of the subject

21. To conduct reliable clinical trials with a potential new drug, it is necessary to establish a dose level that toxicity first appears. This is commonly determined in

Phase I Studies

Phase II Studies

Phase III Studies

Phase IV Studies

22. The history of pharmacology includes a long list of heroes. The person considered to be the founder of American pharmacology is

Claude Bernard

Rudolph Bucheim

John Jacob Abel

Oswald Schmeideberg

23. All of the following are capable of initiating a signal transduction process EXCEPT

Combination of an agonist with its receptor

Combination of an antagonist with its receptor

Combination of a neurotransmitter with its receptor

Combination of a hormone with its receptor

24. Which of the following chemical bonds would create an irreversible combination of an antagonist with its receptor?

Ionic bond

Hydrogen bond

Van der Waals bond

Covalent bond

25. Potency is determined by

Affinity alone

Efficacy alone

Affinity and efficacy

Affinity and intrinsic activity

Efficacy and intrinsic activity

26. Following oral administration, a drug is absorbed into the body, wherein it can exert its action. For a drug given orally, the primary site of drug absorption is

The esophagus

The stomach

The upper portion of the small intestine

The large intestine

27. Patients can exhibit alterations in the rate and extent of drug absorption because of various factors. All of the following factors might affect the rate and/or extent of drug absorption EXCEPT:

Gastric emptying time

Intestinal motility

The presence of food

The formulation of the drug

A generic form of the drug

28. The body has developed defense mechanisms that reduce the amount of foreign chemicals, such as drugs, that enter the body. One of the more prominent of these mechanisms is an efflux transport system that pumps some drugs back into the intestinal lumen following absorption into the enterocytes and that is responsible for the lack of complete absorption of some drugs. This efflux transport system is:

Facilitated diffusion

P glycoprotein

Cytochrome P450 3A

Pinocytosis

29. All of the following statements concerning the blood-brain barrier and the passage of drugs from the systemic circulation into the cerebrospinal fluid are TRUE EXCEPT:

Ionized drugs are more likely to cross into the CSF than un-ionized drugs.

The higher the lipid solubility of a drug, the more likely it will cross into the CSF.

Inflammation of the meninges improves the likelihood that drugs will cross the blood-brain barrier as compared to the uninflamed state (i.e., normal condition).

P glycoprotein serves to pump drugs back into the systemic circulation from endothelial cells lining the blood-brain barrier

30. Which of the following organs or tissues is a potential site for drug accumulation of lead that has been ingested?

Eyes

Fat

Bone

Lungs

Blood

31. Concerning regulation of CYP-mediated drug metabolism, all of the following statements are true EXCEPT

Drugs that competitively inhibit CYP enzymes cause a decrease in concentrations of the object (original) drug

Induction of drug-metabolizing enzymes results in a decrease in concentrations of the object (original) drug, thus potentially reducing efficacy.

Induction of drug-metabolizing enzymes frequently requires the synthesis of new enzyme protein and thus may not occur immediately upon introduction of the inducing agent.

Mechanism-based inactivation results in irreversible inactivation of the enzyme that lasts for the duration of the enzyme molecule.

32. Which of the following CYP enzymes is associated with metabolism of the greatest number of drugs and thus most likely to be involved in drug–drug interactions?

CYP3A4

CYP2C9

CYP2D6

CYP2E1

CYP1A2

33. Conjugation of a drug with glucuronic acid via the glucuronosyl transferases will result in all of the following EXCEPT

Production of a more water-soluble moiety that is more easily excreted

A new compound that may also possess pharmacological activity

A drug molecule that may be more susceptible to biliary elimination

A drug molecule that may undergo enterohepatic recirculation and reintroduction into the bloodstream

A drug with a different pharmacological mechanism of action

34. Concerning the renal excretion of drugs:

Drugs that are ionized in the renal tubule are more likely to undergo passive reabsorption than those that are unionized

Low-molecular-weight drugs are much more likely to be actively secreted than filtered.

Only drug that is not bound to plasma proteins (i.e., free drug) is filtered by the glomerulus

Decreasing renal tubular fluid pH will increase elimination of weakly acidic drugs

35. Drug presence in breast milk is most likely for:

Drugs highly bound to plasma proteins

Lipid-soluble molecules

Large ionized water-soluble molecules

Acidic compounds