Pharm Quiz 6 Questions

Front 1

Glucocorticoids diminish the progressive spread of an inflammatory focus, in part, by:

a. Suppressing pituitary levels of ACTH
b. Reducing the release of lysosomal enzymes which digest surrounding cells
c. Increasing blood pressure
d. Stimulating chemotaxis of white blood cells
e. All of the above

Back 1

b. Reducing the release of lysosomal enzymes which digest surrounding cells

Front 2

Cimetidine is given to a dog that is also being treated with benzodiazepines. The effect you expect will be that the dog will be less sedate and need a higher dose of benzodiazepines.

a. True
b. False

Back 2

b. False

Front 3

Which of the following antithyroid drugs will inhibit peripheral tissue 5'-deiodination of T4 to T3 as well as thyroidal production of thyroid hormones?

a. Methimazole (MMI)
b. Radiocontrast agents (such as iopanoic acid)
c. Propylthiouracil (PTU)
d. a and b
e. b and c

Back 3

e. b and c

Front 4

A succinate ester attached to the glucocorticoid base structure allows this preparation to be administered by which of the following routes?

a. Intravenous
b. Subcutaneous
c. Topically on the cornea
d. Intraarticular
e. All of the above

Back 4

e. All of the above

Front 5

Molly is an epileptic and is treated with phenobarbital. She develops a gastric ulcer and the vet treats her with cimetidine, an agent that inhibits the microsomal enzyme system. What would you expect to see?

a. Molly becomes more active
b. Molly becomes more sleepy

Back 5

b. Molly becomes more sleepy

Front 6

Flunixin is used to treat which of the following non-analgesic clinical conditions?

a. Renal failure
b. Autoimmune skin disease
c. Hypotension associated with endotoxemia
d. Congestive heart failure
e. Urinary bladder stones

Back 6

c. Hypotension associated with endotoxemia

Front 7

Aspirin is a potent inhibitor of platelet aggregation at low dosages administered at infrequent intervals. Which two reasons explain this effect?
I. Platelet cyclooxygenase and thromboxane production is very sensitive to aspirin.
II. Vascular endothelial cell cyclooxygenase and prostacyclin (PGI2) production is very sensitive to aspirin.
III. Platelets cannot resynthesize cyclooxygenase
IV. Vascular endothelial cells cannot resynthesize cyclooxygenase.

a. I and II
b. I and III
c. II and III
d. III and IV
e. I and IV

Back 7

b. I and III

Front 8

Dr. Knowitall has just recently attended continuing education seminars. He tells Dr. Doitbetter that misoprostol, a prostaglandin E derivative, is a new drug that can be used for the treatment of gastric ulcers. It works by:

a. increasing gastric mucous production
b. increasing bicarbonate secretion
c. increasing blood flow
d. inhibiting pepsin
e. all of the above

Back 8

e. all of the above

Front 9

Inhibition of cyclooxygenase results in:

a. a decrease in the synthesis of norepinephrine
b. a reduction in the formation of angiotensin II
c. decreased synthesis of PGE2
d. decreased synthesis of leukotrienes
e. reduced metabolism of

Back 9

c. decreased synthesis of

Front 10

When combining antimicrobial drugs, which of the following terms does NOT describe a beneficial result:

a. Synergy
b. Potentiation
c. Additivity
d. Agonism
e. None of the above

Back 10

d. Agonism

Front 11

You seek to use penicillin G in a horse to achieve maximal tissue concentrations before ophthalmological surgery. It distributes rapidly (peak concentration in 1 hour) and you anticipate a 2 hour surgery. The elimination halflife is 0.5 hours. If the volume of distribution of this drug is 0.5 liters/kg in the horse, and your minimum inhibitory plasma drug concentration (MIC) is 0.5 micrograms/ml, what loading dosage (mg/kg) would you need to administer 1 hour before surgery to reach 32 micrograms/ml? (Note, this is 64 times the MIC, the initial level necessary to stay above the MIC for 6 halflives or 3 hours). [Hint: watch your units!] (Review Type Question)
a. 0.25
b. 1
c. 1.6
d. 16
e. 250

Back 11

d. 16

Front 12

You are faced with treating a 10 year old male miniature poodle for its first bout of increased urinary frequency possibly associated with a lower urinary tract infection. Which (one or more) of the following clinical procedures would most help you empirically determine if antimicrobial therapy is appropriate and also help you choose an appropriate drug to send home with the owners THAT day?
a. Doing a rectal examination to palpate the prostate
b. Performing a gram stain of the urinary sediment
c. Bacterial culture of the urine
d. a and b
e. b and c

Back 12

d. a and b

Front 13

Why are high concentrations of the beta lactam antimicrobials penicillins and cephalosporins achieved in the urine?
a. These drugs are weak bases and are moved up a concentration gradient to the urine by the organic base transport system in the proximal tubules of the kidney.
b. These drugs are weak acids and are moved up a concentration gradient to the urine by the organic acid transport system in the proximal tubules of the kidney.
c. These weakly basic drugs are transported into the urine down a concentration gradient by distal tubular cells.
d. These drugs are all poorly protein bound and are therefore filtered freely at the glomerulus.
e. None of the above is the reason.

Back 13

b. These drugs are weak acids and are moved up a concentration gradient to the urine by the organic acid transport system in the proximal tubules of the kidney.

Front 14

Which two antimicrobial drugs both represent agents with a “wide” spectrum, including antirickettsial and/or antiprotozoal activity?
a. Aminoglycosides; Macrolides
b. Quinolones; Penicillins
c. Tetracyclines; Sulfonamides
d. Penicillins; Tetracyclines
e. Cephalosporins; Tetracyclines

Back 14

c. Tetracyclines; Sulfonamides

Front 15

Which statement best describes the trend of the antimicrobial spectrum difference as one moves from a first generation cephalosporin to a third generation cephalosporin?
a. More effective for gram positive infections.
b. More effective for gram negative infections
c. More effective for anaerobes
d. More effective against penicillinase-producing gram positive organisms
e. b, c, and d

Back 15

e. b, c, and d

Front 16

Which of the following would be an antagonistic antimicrobial combination?
a. A tetracycline and an aminoglycoside
b. A penicillin and an aminoglycoside
c. A sulfa and trimethoprim
d. A cephalosporin and a fluoroquinolone
e. None of the above

Back 16

a. A tetracycline and an aminoglycoside

Front 17

Which of the following statements regarding aminoglycoside antimicrobials is TRUE?
a. They are widely distributed into tissues due to high lipid solubility.
b. They are bacteriostatic at therapeutic concentrations.
c. They are well-absorbed from the gastrointestinal tract.
d. They are not effective against anaerobic organisms.
e. They are drugs of choice in treatment of abscesses.

Back 17

d. They are not effective against anaerobic organisms.

Front 18

Which of the following statements best characterizes the difference in antimicrobial spectrum of a third generation cephaloporin compared to a first generation cephalosporin?
a. Third generation cephalosporins generally have a better gram positive and rickettsial spectrum than first generation cephalosporins.
b. Third generation cephalosporins generally have a better gram positive and anerobic spectrum than first generation cephalosporins.
c. Third generation cephalosporins generally have a better gram negative and gram positive spectrum than first generation cephalosporins.
d. Third generation cephalosporins generally have a better gram negative and anaerobic spectrum than first generation cephalosporins.
e. None of the above characterizes the difference between first and third generation cephalosporins.

Back 18

d. Third generation cephalosporins generally have a better gram negative and anaerobic spectrum than first generation cephalosporins.

Front 19

Which of the following statements about antimicrobial mechanisms of action is FALSE?:
a. Sulfa drugs prevent the incorporation of PABA into folic acid.
b. Penicillins inactivate transpeptidase, a critical enzyme for bacterial cell well synthesis.
c. The aminoglycoside amikacin interferes with the function of the 30S ribosome involved in bacterial protein synthesis.
d. Trimethoprim is a component of potentiated sulfonamides which inhibits bacterial intermediary metabolism by blocking dihydrofolate reductase.
e. Fluoroquinolones inhibit the 50S ribosome inolved with bacterial protein synthesis.

Back 19

e. Fluoroquinolones inhibit the 50S ribosome inolved with bacterial protein synthesis.

Front 20

Which of the following is sufficient to explain how one may take advantage of the in vivo synergistic antimicrobial effect of an aminoglycoside with a penicillin when the two drugs inactivate each other in vitro?
a. Synthesize a penicillin which is not an acid, so it does not inactivate the basic aminoglycoside.
b. Synthesize an aminoglycoside which is not an acid, so it does not inactivate the basic penicillin.
c. Administer the drugs in separate syringes.
d. Administer the two drugs at intervals at least 24 hours apart.
e. c and d

Back 20

c. Administer the drugs in separate syringes.

Front 21

Which of the following is not considered an essential for successful antibacterial therapy?
a. Drug must be present for a sufficient amount of time.
b. The drug must be bactericidal
c. The drug must come in contact with the microbe.
d. The drug must be present in high enough concentration
e. The microbe must be sensitive to the drug.

Back 21

b. The drug must be bactericidal

Front 22

Which of the following drug combinations is a synergistic combination of two antimicrobial drugs?
a. Amoxicillin and clavulanic acid
b. Trimethoprim and sulfadiazine
c. Lincosamide lincomycin and penicillin G
d. Fluroquinolone enrofloxacin and chloramphenicol
e. a and b

Back 22

b. Trimethoprim and sulfadiazine

Front 23

Which of the following drug classes cannot be given in the same syringe as a penicillin drug, but does, when given separately, successfully synergize with the penicillin?
a. Quinolones
b. Lincosamides
c. Sulfonamides
d. Tetracyclines
e. Aminoglycosides

Back 23

e. Aminoglycosides

Front 24

Which of the following does NOT pair up an antimicrobial drug class properly with its mechanism of action?
a. Macrolide; Inhibits ribosome synthesis
b. Chloramphenicol; inhibits 50S ribosomal subunit effect on peptide chain elongation
c. Penicillins; inhibits cell wall synthesis by altering peptidoglycan crosslinking
d. Sulfonamide; competitively inhibit acetoacetate in its role of citric acid synthesis
e. Quinolones; inhibit bacterial DNA gyrase enzyme

Back 24

d. Sulfonamide; competitively inhibit acetoacetate in its role of citric acid synthesis

Front 25

Which of the following correctly pairs up an antimicrobial drug class properly with one of its primary toxicities?
a. Sulfonamides; bile stone formation
b. Quinolones; Cartilage damage in young animals
c. Chloramphenicol; renal disease
d. Aminoglycosides; hepatotoxicity
e. Cephalosporins; synergistic hepatotoxicity with loop diuretics

Back 25

b. Quinolones; Cartilage damage in young animals

Front 26

Which of the following antimcrobials is also used at low dosages intravenously to bind endotoxin?
a. Flunixin
b. Cuprimyxin
c. Polymixin
d. Amoxicillin
e. Richard Nixon

Back 26

c. Polymixin

Front 27

Which of the following antimicrobial drugs or classes is LEAST lipophilic?
a. Chloramphenicol
b. Fluroquinolones
c. Trimethoprim/sulfonamide
d. Aminoglycosides
e. Tetracyclines

Back 27

d. Aminoglycosides

Front 28

Which of the following antimicrobial drugs is generally considered bactericidal when given alone at standard dosages?
a. Flunixin
b. Lincosamides
c. Cephalosporins
d. Tetracyclines
e. Sulfonamides

Back 28

c. Cephalosporins

Front 29

Which drugs are NOT generally useful against anaerobic infections?
a. The semisynthetic penillin amoxicillin
b. Penicillin G
c. Metronidazole
d. Aminoglycosides
e. All of the above are useful for anaerobic infections

Back 29

d. Aminoglycosides

Front 30

Which drug characteristic is most important when considering the choice of an antimicrobial to manage a chronic infection of the central nervous system?
a. Long elimination halflife
b. Anaerobic spectrum
c. Bacteriocidal mechanism
d. DNA synthesis inhibitor
e. Lipophilicity

Back 30

e. Lipophilicity

Front 31

When using aminoglycosides or fluoroquinolone antimicrobials, which of the following best represents the pharmacokinetic monitoring target for most effective and/or least toxic therapy?
(Tmax = time to maximum plasma drug concentration; Cmax = maximum plasma drug concentration; MIC = minimum inhibitory concentration; AUC = area under the plasma concentration curve)
a. Longest Tmax
b. Highest Cmax/MIC or AUC/MIC
c. Lowest Cmax/MIC
d. Longest duration of time when plasma drug concentration is > MIC
e. c and d

Back 31

b. Highest Cmax/MIC or AUC/MIC

Front 32

When surgically treating a contaminated wound (as in a flesh wound of a dog hit by a car), which of the following statements describe an appropriate choice, timing, and pattern of perioperative antimicrobial therapy?
a. Antimicrobial tehrapy is not indicated as you can use appropriate surgical technique to debride the wound.
b. Administer a semisynthetic penicillin or cephalosporin at high intermittent intravenous doses starting preferably no later than 4 hours after the wound but timed to reach peak plasma concentrations at the beginning of surgery.
c. Administer ampicillin or a cephalosporin by continuous intravenous infusion starting an hour before surgery, but not later than 8 hours following the trauma.
d. Give the fluoroquinolone enrofloxacin orally at the time of anesthetic induction before debriding the wound.
e. Give the aminoglycoside amikacin by continuous infusion starting at the time of anesthetic induction before debriding the wound

Back 32

b. Administer a semisynthetic penicillin or cephalosporin at high intermittent intravenous doses starting preferably no later than 4 hours after the wound but timed to reach peak plasma concentrations at the beginning of surgery.

Front 33

When an antimicrobial drug is called "time-dependent," the "time" being referred to is when the antimicrobial drug…
a. plasma concentration achieves its maximum (i.e. peak).
b. plasma concentration becomes undetectable after a single dose
c. plasma concentration is above the minimum inhibitory concentration (MIC).
d. begins to suppress microbial growth.
e. becomes bactericidal in action.

Back 33

c. plasma concentration is above the minimum inhibitory concentration (MIC).

Front 34

What problem in pups is most frequently associated with the use of tetracyclines in a pregnant bitch?
a. Nephrotoxicity
b. Discoloration of bones and teeth
c. Drug allergy
d. Yellow discoloration of the skin
e. Increased incidence of bone fractures

Back 34

b. Discoloration of bones and teeth

Front 35

What pair of reasons (separated by the semicolon) best accounts for the clinical efficacy and improved safety by administering the aminoglycoside gentamicin at an interval 12 times longer than its halflife (2 hours?)
a. Gentamicin distributes slowly to its eventual apparent volume of distribution; Aminoglycosides inhibit protein synthesis at the 30S ribosomal subunit.
b. Gentamicin is lipophilic and achieving a higher peak concentration results in more tissue penetration; Gentamicin is mainly eliminated by the liver and less frequent administration reduces its hepatic elimination.
c. The toxicity of gentamicin is related to the plasma trough concentration which is diminished with less frequent administration; Antibacterial activity is prolonged by a post-antibiotic effect of aminoglycosides.
d. The toxicity of gentamicin is related to its plasma peak concentration because aminoglycosides are eliminated largely by biliary excretion; gentamicin is considered a “concentration-dependent” drug meaning that it kills by achieving a high peak concentration.
e. None of the above pairs includes two true statements which explain the phenomenon.

Back 35

c. The toxicity of gentamicin is related to the plasma trough concentration which is diminished with less frequent administration; Antibacterial activity is prolonged by a post-antibiotic effect of aminoglycosides.

Front 36

What is the main reason fluoroquinolones are banned from use in food animals in the U.S. (except for one product in poultry)?
a. It causes a dose-dependent reversible bone marrow toxicity in man.
b. It causes an idiosynchratic often fatal marrow toxicity in man.
c. There is concern over the development of bacterial resistance to these drugs by human pathogens.
d. It causes hepatotoxicity in cattle.
e. The tissue halflife in the kidney can be as long as a year.

Back 36

c. There is concern over the development of bacterial resistance to these drugs by human pathogens.

Front 37

What is the role of clavulanic acid when it is combined with the semisynthetic penicillin, amoxicillin?
a. Clavulanic acid has no antimicrobial activity of its own and it inhibits activity of the beta-lactamase enzyme made by the microbe.
b. Clavulanic acid is an aminoglycoside which synergizes with the semisynthetic penicillin.
c. Clavulanic acid inhibits amoxicillin’s clearance by the kidney.
d. Clavulanic acid acidifies the environment allowing the amoxicillin, a weak acid, to penetrate the bacterium more effectively.
e. None of the above are correct.

Back 37

a. Clavulanic acid has no antimicrobial activity of its own and it inhibits activity of the beta-lactamase enzyme made by the microbe.

Front 38

What is the main reason chloramphenicol is banned from use in food animals in the U.S?
a. It causes a dose-dependent reversible bone marrow toxicity in man
b. It causes an idiosynchratic irreversible bone marrow toxicity in man
c. It causes hepatotoxicity in cattle.
d. It inhibits cytochrome P450-mediated drug metabolism.
e. The tissue halflife in the kidney can be as long as a year.

Back 38

b. It causes an idiosynchratic irreversible bone marrow toxicity in man

Front 39

What chemical structure, shared between penicillins and cephalosporins, is key to the mechanism of action of these antimicrobials?
a. reactive ethyl ester attached to a phenyl ring
b. multiple carboxyl substituents on a cyclohexane ring
c. multiple chlorine substitutions on a phenyl ring
d. 6 element ring including an sulfonyl linkage
e. 4 element ring including an amide linkage

Back 39

e. 4 element ring including an amide linkage

Front 40

What characteristic of an antimicrobial is particularly useful in managing the intracellular Brucella organism?
a. Effectiveness against anaerobes
b. Lipophilicity
c. Weak base
d. Can be given orally
e. Not a protein synthesis inhibitor

Back 40

b. Lipophilicity

Front 41

Two antimicrobials which currently banned from use in most food animal species in the U.S. due to human safety or bacterial resistance concerns are:
a. Penicillin G; Aminoglycosides
b. Sulfonamides; Macrolides
c. Tetracyclines; Lincosamides
d. Chloramphenicol; Fluoroquinolones
e. All of the above drug pairs can be used in food animals in the U.S.

Back 41

d. Chloramphenicol; Fluoroquinolones

Front 42

The serum halflife of potassium penicillin G is short requiring either constant rate intravenous or q 4-6 hour intravenous or intramuscular administration. What pharmaceutical alteration is used most commonly today in veterinary medicine to allow less frequent intramuscular administration?
a. Use of the sodium salt
b. Addition of a pivalate ester
c. Chemical alteration to increase the drug's acid resistance
d. Complexation with the local anesthetic procaine
e. Co-administration with a compound which competes with the renal secretion of penicillin

Back 42

d. Complexation with the local anesthetic procaine

Front 43

The serum halflife of potassium penicillin G is 0.5 hours in the horse and the serum halflife of gentamicin is 2 hours. Which of the following (note: all parts must be correct) explains why penicillin is generally administered every 6 hours when gentamicin is often given only once every 24 hours?
a. Gentamicin is a time-dependent antimicrobial meaning that its efficacy is determined by the time above a minimum inhibitory concentration (MIC), whereas penicillin is concentration-dependent antimicrobial meaning that its antimicrobial efficacy is optimized by achieving high peak concentrations.
b. Gentamicin, unlike penicillin, is nephrotoxic and more frequent administration diminishes this tendency.
c. Penicillin is a time-dependent antimicrobial meaning that its efficacy is determined by the time above a minimum inhibitory concentration (MIC), whereas gentamicin is concentration-dependent meaning that its antimicrobial efficacy is optimized by achieving high peak concentrations.
d. a and b
e. b and c

Back 43

c. Penicillin is a time-dependent antimicrobial meaning that its efficacy is determined by the time above a minimum inhibitory concentration (MIC), whereas gentamicin is concentration-dependent meaning that its antimicrobial efficacy is optimized by achieving high peak concentrations.

Front 44

The potentiated sulfonamide trimethoprim/sulfa inhibits bacterial growth at 2 sequential steps in DNA synthesis. The two steps are: (both must be correct and in the correct order).
a. 1) Inhibition of beta lactamase by the sulfonamide; 2) Inhibition of DNA gyrase enzyme by trimethoprim
b. 1) Inhibition of DNA gyrase enzyme by the sulfonamide; 2) Inhibition of beta lactamase by trimethoprim
c. 1) Inhibition of folic acid synthesis from PABA by trimethoprim; 2) Inhibition of dihydrofolate reductase by the sulfonamide.
d. 1) Inhibition of folic acid synthesis from PABA by sulfonamide; 2) Inhibition of dihydrofolate reductase by trimethoprim.
e. 1) Inhibition of dihydrofolate reductase by the potentiator such as trimethoprim; 2) Inhibition of folic acid synthesis from PABA by sulfonamide.

Back 44

d. 1) Inhibition of folic acid synthesis from PABA by sulfonamide; 2) Inhibition of dihydrofolate reductase by trimethoprim.

Front 45

The concept of antibacterial activity being bactericidal or bacteriostatic is an oversimplification because:
a) bacteria really don’t die when exposed to “bactericidal” antimicrobial drugs
b) using too low a dosage of a bacteriocidal agent can make the agent bactiostatic
c) using a very high dosage of a bacteriostatic agent can result in killing the organism
d) a and c
e) b and c

Back 45

e) b and c

Front 46

Sulfonamide crystals in the urine are generally not a problem in which species which lacks enzymes to acetylate the sulfonamide?
a) horse
b) cow
c) dog
d) man
e) chicken

Back 46

c) dog

Front 47

Skin infections in dogs and cats are often due to ß-lactamase-producing Staphylococcus infections. Which of the following antimicrobials would be narrow spectrum yet have a high likelihood of being effective in such an infection?
a. Semisynthetic penicillin amoxicillin
b. Semisynthetic penicillin oxacillin
c. Aminoglycoside amikacin
d. Sulfonamide sulfadiazine
e. Tetracycline

Back 47

b. Semisynthetic penicillin oxacillin

Front 48

Semisynthetic penicillins like ampicillin or cephalosporins are reasonable first-time empirical choices for urinary tract infections (UTIs) in dogs and cats. What two facts account for this efficacy?
a. The majority of UTIs are due to gram positive organisms susceptible to these drugs; ampicillin or cephalosporin are easily instilled into the urinary bladder.
b. The majority of UTIs are due to gram positive organisms susceptible to these drugs; ampicillin and cephalosporin are secreted in high concentration into the urine.
c. The majority of UTIs are due to gram negative organisms susceptible to these drugs at high concentrations; ampicillin and cephalosporin are secreted in high concentration into the urine.
d. The majority of UTIs are due to gram negative organisms susceptible to these drugs; ampicillin and cephalosporin reach the urine mainly by glomerular filtration.
e. The majority of UTIs are due to anaerobic organisms susceptible to these drugs; ampicillin and cephalosporin reach high concentration in the kidney due to high lipid solubility.

Back 48

c. The majority of UTIs are due to gram negative organisms susceptible to these drugs at high concentrations; ampicillin and cephalosporin are secreted in high concentration into the urine.

Front 49

Prophylactic usage of bactericidal antimicrobials is most rational in which of the following clinical scenarios?
a. Following placement of intravenous and urinary catheters for fluid and insulin therapy in a diabetic ketoacidotic patient in the intensive care unit.
b. Following placement of an intravenous catheter for fluid therapy in a dehydrated dog with sunstroke in the intensive care unit.
c. Perioperatively for an routine ovariohysterectomy (spay) surgery
d. Following placement of an intravenous catheter in a dog with “garbage” gastroenteritis not resulting in sepsis
e. During chronic administration of a glucocorticoid in allergic skin disease

Back 49

a. Following placement of intravenous and urinary catheters for fluid and insulin therapy in a diabetic ketoacidotic patient in the intensive care unit.

Front 50

Polymixin, at antimicrobial dosages, are too toxic for systemic administration to mammals. However, at low dosages, polymixin is administered to:
a) bind flunixin
b) bind the pili of gram negative bacteria
c) act as a detergent to clean your surgical scrubs
d) bind endotoxins
e) all of the above

Back 50

d) bind endotoxins

Front 51

Plasmid-derived antimicrobial resistance is most common with which one of the following antimicrobial classes?
a. Penicillins
b. Cephalosporins
c. Aminoglycosides
d. Sulfonamides
e. Lincosamides

Back 51

c. Aminoglycosides

Front 52

Perioperative prophylaxis with antimicrobials is a controversial topic. However, most agree that, assuming proper aseptic technique is used, perioperative prophylactic antimicrobial therapy is NOT rational in wounds which are:
a) clean
b) clean-contaminated like urogenital tract surgery
c) contaminated wounds like a recent tissue trauma
d) dirty or infected wounds
e) none of the above – antimicrobials are always indicated perioperatively

Back 52

a) clean

Front 53

Once-a-day dosing of aminoglycosides is less nephrotoxic than dividing the same dosage into more frequent doses because:
a. toxicity of these drugs is associated with a higher trough concentration of plasma.
b. the duration of the kidney's exposure to the drugs during the pharmacokinetic elimination phase is more predictive of toxicity than the average serum concentrations.
c. The kidney has a longer interdose period to recover from the toxic insult caused by the drug.
d. a, b and c
e. None of the above is true.

Back 53

d. a, b and c

Front 54

Of protein synthesis inhibitors, which antimicrobial drug is banned from food animal use because of irreversible aplastic anemias it causes in man?
a. The lincosamide clindamycin
b. The sulfa drug sulfadiazine
c. Chloramphenicol
d. The cephalosporin cephalexin
e. Quinolones

Back 54

c. Chloramphenicol

Front 55

Of the following antimicrobials or antimicrobial classes, which are NOT generally considered to be bacteriostatic at therapeutic concentrations?
a. Chloramphenicol
b. Trimethoprim/sulfadiazine combination
c. Tetracyclines
d. Lincosamides
e. Macrolides

Back 55

b. Trimethoprim/sulfadiazine combination

Front 56

Mastitis is an important problem of dairy cattle. In a survey of the Georgia Veterinary Diagnostic Laboratory in Tifton in 1994, statistics showed cultured microbes were sensitive in the following percentages.E. coli: 85% sensitive to ampicillin; 69% sensitive to cephalosporin Streptococcus spp: 99% sensitive to ampicillin; Staphylococcus spp: 98% sensitive to Novobiocin. Based upon these data, what would be a reasonable dry cow (intermilking period) treatment to prevent mastitis by these three most common milk pathogens?
a. Daily ampicillin IM injections
b. Periodic alternating intramammary ampicillin and Novobiocin administration
c. Periodic intramammary Novobiocin
d. Periodic intramammary ampicillin
e. Daily IM erythromycin injections

Back 56

b. Periodic alternating intramammary ampicillin and Novobiocin administration

Front 57

Infectious (transferable) drug resistance, involving multiple drug resistance genes via pili by gram negative organisms, is called:
a. plasmid resistance
b. beta-lactamase resistance
c. DNA gyrase resistance
d. Acquired resistance
e. None of the above

Back 57

a. plasmid resistance

Front 58

If faced with a serious gram negative infection, which of the following antimicrobials would NOT be an appropriate empirical choice for therapy because of its spectrum?
a. Enrofloxacin, a fluroquinolone
b. Third generation cephalosporin
c. Amikacin, an aminoglycoside
d. Erythromycin, a macrolide
e. a,b,c and d are all appropriate empirical choices for a gram negative infection

Back 58

d. Erythromycin, a macrolide

Front 59

If an animal contracts an infection by an organism residing in your hospital, this animal has a (n):
a. nosocomial infection
b. colonization resistance infection
c. plasmid resistant infection
d. a nasal infection
e. prophylactic infection

Back 59

a. nosocomial infection

Front 60

Combinations for known mixed infections require four quadrant therapy, that is antimicrobial activity against gram negative, gram positive, aerobic and and anaerobic bacteria. Which of the following drugs used in combination DO NOT achieve this spectrum of coverage?
a. Fluroquinolone enrofloxacin; semisynthetic penicillin amoxicillin
b. Semisynthetic penicillin ticarcillin; aminoglycoside gentamicin
c. Clindamycin; aminoglycoside amikacin
d. Semisynthetic penicillin ampicillin; aminoglycoside gentamicin; metronidazole
e. Trimethoprim/sulfa; macrolide erythromycin

Back 60

e. Trimethoprim/sulfa; macrolide erythromycin

Front 61

A horse, grazing in a field, is gored in its flank by a bull. Which statement is most appropriate way to describe the wound and whether antimicrobial therapy is merited?
a. This is a clean-contaminated wound and use of antimicrobial prophylaxis is an individual clinician's choice.
b. This is a clean wound and antimicrobial therapy isn't indicated.
c. This is a dirty wound and antimicrobial therapy should be directed at all 4 quadrants - gram positive, gram negative, aerobes and anaerobes.
d. This is a dirty wound and penicillin treatment should be the only antimicrobial therapy necessary because a beta lactamase-producing Staphylococcus is likely the only contaminant.
e. None of the above.

Back 61

c. This is a dirty wound and antimicrobial therapy should be directed at all 4 quadrants - gram positive, gram negative, aerobes and anaerobes.

Front 62

A mechanism by which a microorganism can become resistant to a drug without previously being exposed to the drug involves:
a. Natural selection
b. Increased transport of drug into the microbe
c. Plasmid resistance
d. Increased drug metabolism by the animal
e. None of the above

Back 62

c. Plasmid resistance

Front 63

Adaptive post-exposure resistance associated with gram negative organisms refers to which phenomenon following exposure to multiple frequent dosages of an antimicrobial drug?:
a. The transient increase in uptake of a drug into the bacterium
b. The transient decrease in uptake of a drug into the bacterium
c. The transient elevation in MIC (minimum inhibitory concentration)
d. a and c
e. b and c

Back 63

e. b and c

Front 64

Adverse reactions to the aminoglycoside antimicrobials include all of the following EXCEPT:
a. Auditory ototoxicity
b. Vestibular ototoxicity
c. Bone marrow suppression
d. Neuromuscular blockade
e. Nephrotoxicity

Back 64

c. Bone marrow suppression

Front 65

All of the following antimicrobials are susceptible to bacterial resistance caused by the secretion of beta-lactamases EXCEPT:
a. Penicillin G
b. The semisynthetic penicillin, ampicillin
c. Penicillin V
d. The tetracycline, oxytetracycline
e. The cephalosporin, cephalexin

Back 65

d. The tetracycline, oxytetracycline

Front 66

All of the drugs EXCEPT WHICH ONE would be reasonable empirical choices for an anaerobic bacterial infection?
a. Metronidazole
b. Penicillin G
c. Amoxicillin and clavulanic acid
d. Third Generation Cephalosporin
e. Aminoglycoside gentamicin

Back 66

e. Aminoglycoside gentamicin

Front 67

Antimicrobial drugs are often classified in text books by mechanism of action and whether that mechanism will result in killing or inhibiting growth of a microbe. However, when applying antimicrobial therapy to a patient, what information is necessary before establishing whether a drug will actually be bactericidal or bacteriostatic in that patient?

a. Drug route of administration
b. Drug halflife
c. Drug route of elimination from the body
d. Drug lipophilicity
e. Drug concentration at the site of infection

Back 67

e. Drug concentration at the site of infection

Front 68

Bactericidal drugs should be considered in all but which of the following clinical situations?:
a. In an immunosuppressed patient
b. In life-threatening septicemia
c. For treatment of infection during routine glucocorticoid use
d. a,b, and c are all appropriate uses of bactericidal drugs.
e. None of the above is true.

Back 68

d. a,b, and c are all appropriate uses of bactericidal drugs.

Front 69

Clavulanic acid is given in combination with the penicillin class drug amoxicillin (commercial combination product is Clavamox®) in order to:
a. reduce the risk of allergic reactions to amoxicillin.
b. prolong amoxicillin’s halflife in the bloodstream.
c. synergize as a second antimicrobial drug with greater efficacy against gram negative bacteria than amoxicillin.
d. inactivate ß-lactamase thereby extending amoxicillin’s antibacterial spectrum.
e. reduce the severity of diarrhea seen with penicillins.

Back 69

d. inactivate ß-lactamase thereby extending amoxicillin’s antibacterial spectrum.

Front 70

Chloramphenicol is not allowed in food animal medicine because:
a. it is concentrated in the kidney tissue and retained for over a year.
b. miniscule quantities can cause an irreversible bone marrow suppression in man.
c. there is a dose- and time-dependent reversible bone marrow suppression in man.
d. there is concern over the development of resistance of animal pathogens which will eventually affect antimicrobial efficacy in human infections.
e. a and b

Back 70

b. miniscule quantities can cause an irreversible bone marrow suppression in man.