Antibacterials

Question 1

Clinical Vignette: A 45-year-old female patient comes to your clinic with symptoms of a urinary tract infection (UTI). She is allergic to penicillin. You are considering options for antibiotic therapy.

Question: Which of the following antibiotics is bactericidal and could potentially be used in this patient?

Options:
A. Chloramphenicol
B. Quinolones
C. Macrolides
D. Trimethoprim

Answer 1

Correct Answer: B. Quinolones

Explanation: Quinolones are bactericidal agents and could be considered in a patient with a UTI who is allergic to penicillin.

Memory Tool: “Quinolones Kill Quickly” - all three words start with ‘Q’ or ‘K’ sound to remember that Quinolones are bactericidal.

Reference Citation: Table 55.4

Rationale: Understanding the distinction between bacteriostatic and bactericidal agents is crucial for effective treatment, especially in patients with allergies to certain classes of antibiotics.

Question 2

Clinical Vignette: A 25-year-old male patient is diagnosed with a UTI. Due to a history of kidney issues, you opt for a bacteriostatic agent.

Question: Which of the following is a suitable bacteriostatic agent for treating his UTI?

Options:
A. Aminoglycosides
B. Chloramphenicol
C. β-lactams
D. Vancomycin

Answer 2

Correct Answer: B. Chloramphenicol

Explanation: Chloramphenicol is a bacteriostatic agent that could be suitable for treating a UTI in a patient with kidney issues.

Memory Tool: “Chloramphenicol Calms, Doesn’t Kill” - the two ‘C’s help you remember that it’s bacteriostatic, not bactericidal.

Reference Citation: Table 55.4

Rationale: Knowing the bacteriostatic options is important when treating patients with specific medical histories that may limit the use of bactericidal agents.

Question 3

Clinical Vignette: A 60-year-old male with diabetes has recurrent UTIs. He is currently being treated with nitrofurantoin.

Question: Which of the following statements about nitrofurantoin is true?

Options:
A. It is strictly bactericidal
B. It is strictly bacteriostatic
C. It can be either bactericidal or bacteriostatic, depending on the dose and organism
D. It is neither bactericidal nor bacteriostatic

Answer 3

Correct Answer: C. It can be either bactericidal or bacteriostatic, depending on the dose and organism

Explanation: Nitrofurantoin is generally bacteriostatic, but it can be bactericidal in high doses and against certain organisms.

Memory Tool: “Nitro-flexible” - Nitrofurantoin is flexible in its bacteriostatic and bactericidal properties.

Reference Citation: Table 55.4, last line

Rationale: This information is important for physicians who might need to adjust treatment strategies based on patient characteristics or resistance patterns.

Question 4

Clinical Vignette: A 70-year-old male with chronic kidney disease (CKD) presents with symptoms of a severe UTI. You are considering antibiotic options for treatment.

Question: Which of the following antibiotics is bactericidal but should be used cautiously in this patient due to his CKD?

Options:
A. Aminoglycosides
B. Clindamycin
C. Sulfonamides
D. Macrolides

Answer 4

Correct Answer: A. Aminoglycosides

Explanation: Aminoglycosides are bactericidal agents but need to be used cautiously in patients with kidney issues, such as CKD, due to nephrotoxicity.

Memory Tool: “Aminoglyco-Side Effects” - Remember that aminoglycosides have side effects like nephrotoxicity.

Reference Citation: Table 55.4

Rationale: Understanding the side-effect profiles of bactericidal agents is important, particularly in patients with existing kidney issues.

Question 5

Clinical Vignette: A 40-year-old female presents with a UTI. She has a complicated medical history, including a penicillin allergy.

Question: Which of the following antibiotics is bacteriostatic and a suitable alternative for someone allergic to penicillin?

Options:
A. Clindamycin
B. Vancomycin
C. Quinolones
D. Aminoglycosides

Answer 5

Correct Answer: A. Clindamycin

Explanation: Clindamycin is a bacteriostatic agent that could be an alternative in a patient allergic to penicillin.

Memory Tool: “Cautious Clinda” - ‘Cautious’ for bacteriostatic and ‘Clinda’ as in Clindamycin.

Reference Citation: Table 55.4

Rationale: Knowing the alternatives to penicillin is critical when the patient has allergies, and being aware that it’s bacteriostatic helps in clinical decision-making.

Question 6

Clinical Vignette: A 50-year-old male presents with symptoms of a UTI. He is allergic to penicillin and sulfonamides.

Question: Which of the following is a bacteriostatic antibiotic option for this patient?

Options:
A. Vancomycin
B. Tetracycline
C. Macrolides
D. β-lactams

Answer 6

Correct Answer: C. Macrolides

Explanation: Macrolides are bacteriostatic and can be a suitable option for someone allergic to both penicillin and sulfonamides.

Memory Tool: “Macro-mellow” - ‘Macro’ for Macrolides and ‘mellow’ to remember it’s bacteriostatic.

Reference Citation: Table 55.4

Rationale: Being familiar with bacteriostatic agents that can serve as alternatives in case of allergies is crucial.

Question 7

Clinical Vignette: A colleague in your practice expresses concern that bacteriostatic antibiotics may not be effective for certain patients, worrying that the infection may return after treatment is complete.

Question: What is the primary mechanism by which bacteriostatic antibiotics help in the eradication of bacterial infections?

Options:
A. They kill bacteria directly.
B. They prevent bacterial replication, allowing the host’s immune system to clear the infection.
C. They target bacterial toxin production.
D. They promote competitive inhibition by fostering growth of non-pathogenic bacteria.

Answer 7

Correct Answer: B. They prevent bacterial replication, allowing the host’s immune system to clear the infection.

Explanation: Bacteriostatic antibiotics work by inhibiting bacterial growth and replication. This allows the host’s immune system to catch up and effectively eliminate the bacteria.

Memory Tool: “Static Stops, System Sweeps” - ‘Static’ for bacteriostatic stopping growth, and ‘System’ for the immune system sweeping away the bacteria.

Reference Citation: N/A (Based on the inquiry about bacteriostatic antibiotics)

Rationale: It’s essential to understand the role of bacteriostatic antibiotics, particularly in their synergistic relationship with the immune system, for effective clinical decision-making.

Question 8

Clinical Vignette: A 35-year-old woman with recurrent UTIs is considering antibiotic treatment options. She has been previously treated with β-Lactams.

Multiple-Choice Options:

A) Inhibition of bacterial DNA gyrase
B) Inhibition of ribosomal protein synthesis
C) Inhibition of bacterial cell wall synthesis
D) Antagonism of bacterial folate metabolism

Answer 8

Correct Answer: C) Inhibition of bacterial cell wall synthesis

Explanation: β-Lactams work by inhibiting bacterial cell wall synthesis.

Memory Tool: “β-Lactams Block Building” (Each word starts with a ‘B’).

Reference Citation: Paragraph 1, Table 55.5

Rationale: Understanding the mechanism of action for commonly used antibiotics like β-Lactams is crucial for appropriate treatment selection.

Question 9

Clinical Vignette: A 45-year-old male is not responding well to a β-Lactam antibiotic for his UTI. What could be a reason for drug resistance?

Multiple-Choice Options:

A) Draws folate from the environment
B) Downregulation of drug uptake into bacteria
C) Production of β-lactamase
D) Mutation in DNA gyrase-binding site

Answer 9

Correct Answer: C) Production of β-lactamase

Explanation: β-Lactams often face resistance through the bacterial production of β-lactamase.

Memory Tool: “Bad Luck (BL), β-Lactamase (BL)”

Reference Citation: Paragraph 1, Table 55.5

Rationale: Knowing the common mechanisms of resistance helps in selecting alternative treatments and managing complicated cases.

Question 10

Clinical Vignette: A 50-year-old man is being considered for treatment with Aminoglycosides. What is the mechanism of action for this drug?

Multiple-Choice Options:

A) Inhibition of ribosomal protein synthesis
B) Inhibition of bacterial cell wall synthesis
C) Inhibition of bacterial DNA gyrase
D) Antagonism of bacterial folate metabolism

Answer 10

Correct Answer: A) Inhibition of ribosomal protein synthesis

Explanation: Aminoglycosides inhibit ribosomal protein synthesis in bacteria.

Memory Tool: “Amino’s Affect All Ribosomes”

Reference Citation: Paragraph 2, Table 55.5

Rationale: Knowledge of mechanisms of action ensures better drug selection and effective treatment.

Question 11

Clinical Vignette: A 60-year-old woman’s UTI is not responding to a Quinolone antibiotic. What is a possible mechanism of resistance?

Multiple-Choice Options:

A) Mutation in DNA gyrase-binding site
B) Production of β-lactamase
C) Novel amino acid substitutions
D) Draws folate from environment

Answer 11

Correct Answer: A) Mutation in DNA gyrase-binding site

Explanation: Quinolones can face resistance due to a mutation in the DNA gyrase-binding site of the bacteria.

Memory Tool: “Quick Queries Quit with Quinolone”

Reference Citation: Paragraph 3, Table 55.5

Rationale: Resistance mechanisms for commonly used antibiotics like Quinolones need to be well understood to effectively manage UTIs.

Question 12

Clinical Vignette: A 40-year-old male is being treated for a UTI. The doctor is considering prescribing Fosfomycin. What is the mechanism of action of Fosfomycin?

Multiple-Choice Options:

A) Inhibition of bacterial DNA gyrase
B) Inhibition of bacterial cell wall synthesis
C) Antagonism of bacterial folate metabolism
D) Inhibition of ribosomal protein synthesis

Answer 12

Correct Answer: B) Inhibition of bacterial cell wall synthesis

Explanation: Fosfomycin works by inhibiting bacterial cell wall synthesis.

Memory Tool: “Fix or Seal with Fosfomycin”

Reference Citation: Paragraph 4, Table 55.5

Rationale: Knowing the mechanism of action for Fosfomycin can guide clinicians in treating UTIs effectively, particularly if other drugs are contraindicated.

Question 13

Clinical Vignette: A 28-year-old woman, pregnant and in her second trimester, is being treated for a UTI. Nitrofurantoin is chosen for treatment. What is its mechanism of action?

Multiple-Choice Options:

A) Inhibition of ribosomal protein synthesis
B) Inhibition of several bacterial enzyme systems
C) Inhibition of bacterial cell wall synthesis
D) Antagonism of bacterial folate metabolism

Answer 13

Correct Answer: B) Inhibition of several bacterial enzyme systems

Explanation: Nitrofurantoin works by inhibiting various bacterial enzyme systems.

Memory Tool: “Nitro Nukes Numerous (enzyme systems)”

Reference Citation: Paragraph 5, Table 55.5

Rationale: Understanding Nitrofurantoin’s unique mechanism can help in tailoring treatments for specific patient populations, like pregnant women.

Question 14

Clinical Vignette: A 55-year-old man with a history of recurrent UTIs is being treated with Trimethoprim-Sulfamethoxazole. What is the drug’s mechanism of action?

Multiple-Choice Options:

A) Antagonism of bacterial folate metabolism
B) Inhibition of bacterial cell wall synthesis
C) Inhibition of ribosomal protein synthesis
D) Inhibition of bacterial DNA gyrase

Answer 14

Correct Answer: A) Antagonism of bacterial folate metabolism

Explanation: Trimethoprim-Sulfamethoxazole acts by antagonizing bacterial folate metabolism.

Memory Tool: “Trim and Sulf Trim Folate”

Reference Citation: Paragraph 6, Table 55.5

Rationale: Knowing the mechanism of action is important for managing recurrent UTIs and avoiding drug resistance.

Question 15

Clinical Vignette: A 65-year-old woman with a UTI is allergic to penicillins. Vancomycin is being considered as an alternative. What is its mechanism of action?

Multiple-Choice Options:

A) Inhibition of bacterial cell wall synthesis
B) Inhibition of ribosomal protein synthesis
C) Antagonism of bacterial folate metabolism
D) Inhibition of bacterial DNA gyrase

Answer 15

Correct Answer: A) Inhibition of bacterial cell wall synthesis

Explanation: Vancomycin inhibits bacterial cell wall synthesis, much like β-Lactams but at a different point.

Memory Tool: “Van’s Very Averse to Bacteria’s Building”

Reference Citation: Paragraph 7, Table 55.5

Rationale: An understanding of Vancomycin’s mechanism is crucial for patients who are allergic to other classes of antibiotics like penicillins.

Question 16

Clinical Vignette: A 55-year-old male presents with symptoms of a urinary tract infection. A urine culture reveals the presence of Proteus mirabilis. Which of the following antibiotics would be an appropriate choice for treatment?

A. Amoxicillin or ampicillin
B. Antistaphylococcal penicillins
C. Third-generation cephalosporins (ceftazidime)
D. Vancomycin

Answer 16

Correct Answer: A. Amoxicillin or ampicillin

Explanation for Choices:

A: Amoxicillin or ampicillin covers Gram-negative pathogen Proteus mirabilis, making it an appropriate choice (Paragraph 1, Table 55.6).
B: Antistaphylococcal penicillins do not cover any Gram-negative pathogens, making it unsuitable for this case (Paragraph 1, Table 55.6).
C: Ceftazidime also covers Proteus mirabilis, but it’s a broader-spectrum antibiotic and should be reserved for more severe infections (Paragraph 1, Table 55.6).
D: Vancomycin is not effective against Gram-negative pathogens (Paragraph 1, Table 55.6).
Memory Tool: “AMOX” for “P. MiraB.” Think of Amoxicillin for Proteus miraBilis.

Rationale for Question: Antibiotic selection for specific pathogens is a key aspect of urological practice. Knowledge of which antibiotics are effective against specific pathogens is crucial for appropriate treatment.

Question 17

Clinical Vignette: A 72-year-old female is suspected to have a UTI caused by Methicillin-resistant Staphylococcus aureus (MRSA). Which antibiotic would be best suited for her treatment?

A. Amoxicillin with clavulanate
B. Antistaphylococcal penicillins
C. Third-generation cephalosporins (ceftriaxone)
D. Vancomycin

Answer 17

Correct Answer: D. Vancomycin

Explanation for Choices:

A: Amoxicillin with clavulanate is not effective against MRSA (Paragraph 1, Table 55.6).
B: Antistaphylococcal penicillins are not effective against MRSA (Paragraph 1, Table 55.6).
C: Ceftriaxone is not effective against MRSA (Paragraph 1, Table 55.6).
D: Vancomycin covers all Gram-positive pathogens, including MRSA, making it the best choice (Paragraph 1, Table 55.6).
Memory Tool: “VAN drives over MRSA”. Think of Vancomycin as the go-to for MRSA.

Rationale for Question: Knowing the proper antibiotic to prescribe for specific resistant bacteria is essential for effective treatment and minimizing antibiotic resistance.

Question 18

Clinical Vignette: A 40-year-old man with a history of recurrent UTIs presents with lower abdominal pain. Urine culture reveals Pseudomonas aeruginosa. Which of the following antibiotics should not be used to treat his condition?

A. Antipseudomonal penicillins
B. Third-generation cephalosporins (ceftazidime)
C. Aminoglycosides
D. Pivmecillinam

Answer 18

Correct Answer: D. Pivmecillinam

Explanation for Choices:

A: Antipseudomonal penicillins cover most Gram-negative pathogens, including Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
B: Ceftazidime covers most Gram-negative pathogens, including Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
C: Aminoglycosides cover most Gram-negative pathogens, including Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
D: Pivmecillinam is not effective against Pseudomonas aeruginosa, making it the wrong choice (Paragraph 1, Table 55.6).
Memory Tool: “PivMe Not for Pseudo”. Remember, Pivmecillinam is not for Pseudomonas aeruginosa.

Rationale for Question: Pseudomonas aeruginosa is a common pathogen in complicated UTIs and requires careful antibiotic selection.

Question 19

Question 4: Antibiotic Classes
Clinical Vignette: A 67-year-old man is suspected of having a UTI. The preliminary urine culture suggests a Staphylococcus infection but it is not yet confirmed whether it’s MRSA or not. Which antibiotic class should be avoided until MRSA is ruled out?

A. First-generation cephalosporins
B. Antistaphylococcal penicillins
C. Third-generation cephalosporins (ceftriaxone)
D. Fluoroquinolones

Answer 19

Correct Answer: B. Antistaphylococcal penicillins

Explanation for Choices:

A: First-generation cephalosporins can cover Staphylococcus but not MRSA (Paragraph 1, Table 55.6).
B: Antistaphylococcal penicillins are not effective against MRSA and should be avoided until it’s ruled out (Paragraph 1, Table 55.6).
C: Ceftriaxone can cover Staphylococcus but not MRSA; however, it is broader-spectrum (Paragraph 1, Table 55.6).
D: Fluoroquinolones can be effective against Staphylococcus and may offer a broader spectrum (Paragraph 1, Table 55.6).
Memory Tool: “Anti-Staph = Anti-MRSA?” Remember, antistaphylococcal penicillins are not effective against MRSA.

Rationale for Question: Understanding the limitations of antistaphylococcal penicillins is crucial for avoiding inappropriate treatment in cases where MRSA could be a concern.

Question 20

Clinical Vignette: A 29-year-old female with no significant medical history presents with symptoms of a UTI. Urine culture is pending. Which of the following antibiotics offers the broadest coverage against both Gram-positive and Gram-negative pathogens?

A. Amoxicillin with clavulanate
B. Second-generation cephalosporins (cefoxitin, cefotetan)
C. Third-generation cephalosporins (ceftazidime)
D. Fosfomycin

Answer 20

Correct Answer: C. Third-generation cephalosporins (ceftazidime)

Explanation for Choices:

A: Covers several Gram-positive and Gram-negative pathogens but not as broad as some other options (Paragraph 1, Table 55.6).
B: Covers multiple Gram-positive and Gram-negative bacteria but is not as broad-spectrum as third-generation cephalosporins (Paragraph 1, Table 55.6).
C: Ceftazidime offers the broadest coverage, including most Gram-positive and Gram-negative bacteria, even P. aeruginosa (Paragraph 1, Table 55.6).
D: Fosfomycin has a narrow spectrum, focusing on Enterococci and some Enterobacteriaceae, and is not as versatile (Paragraph 1, Table 55.6).
Memory Tool: “Third’s the Word”. The third-generation cephalosporins offer the broadest coverage.

Rationale for Question: Knowing which antibiotics offer broad-spectrum coverage is essential for empirical treatment while awaiting culture results.

Question 21

Clinical Vignette: A 45-year-old male patient presents with a UTI, and the culture reveals Enterococcus. What antibiotic should be avoided in treating this infection?

A. Vancomycin
B. First-generation cephalosporins
C. Aminoglycosides
D. Nitrofurantoin

Answer 21

Correct Answer: B. First-generation cephalosporins

Explanation for Choices:

A: Vancomycin is effective against all Gram-positive bacteria, including Enterococcus (Paragraph 1, Table 55.6).
B: First-generation cephalosporins do not provide reliable coverage for Enterococcus (Paragraph 1, Table 55.6).
C: Aminoglycosides can be effective against Enterococcus in urine (Paragraph 1, Table 55.6).
D: Nitrofurantoin is effective against Enterococcus (Paragraph 1, Table 55.6).
Memory Tool: “First is the Worst for Enterococcus.” Remember that first-generation cephalosporins are not the best choice here.

Rationale for Question: Recognizing which antibiotics are ineffective against specific pathogens is critical for appropriate treatment.

Question 22

Clinical Vignette: A 55-year-old woman with diabetes mellitus presents with recurrent UTIs. The urine culture reveals Pseudomonas aeruginosa. What would be an appropriate choice of antibiotic?

A. Amoxicillin or ampicillin
B. Aztreonam
C. Pivmecillinam
D. Fosfomycin

Answer 22

Correct Answer: B. Aztreonam

Explanation for Choices:

A: Amoxicillin or ampicillin does not cover Pseudomonas aeruginosa effectively (Paragraph 1, Table 55.6).
B: Aztreonam has excellent coverage against Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
C: Pivmecillinam does not provide coverage against Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
D: Fosfomycin also lacks reliable coverage against Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
Memory Tool: “A to A—Aztreonam for Aeruginosa.”

Rationale for Question: Treatment for UTIs caused by Pseudomonas aeruginosa can be challenging; thus, knowing the right antibiotics is crucial.

Question 23

Clinical Vignette: A 60-year-old patient with a history of recurrent UTIs has a new infection. Methicillin-resistant Staphylococcus aureus (MRSA) has been identified in the culture. What antibiotic class should be avoided in treating this infection?

A. Vancomycin
B. First-generation cephalosporins
C. Antistaphylococcal penicillins
D. Fluoroquinolones

Answer 23

Correct Answer: C. Antistaphylococcal penicillins

Explanation for Choices:

A: Vancomycin is effective against all Gram-positive bacteria, including MRSA (Paragraph 1, Table 55.6).
B: First-generation cephalosporins are not effective against MRSA but could still be considered (Paragraph 1, Table 55.6).
C: Antistaphylococcal penicillins are ineffective against MRSA (Paragraph 1, Table 55.6).
D: Fluoroquinolones have broader coverage, but efficacy against MRSA may vary (Paragraph 1, Table 55.6).
Memory Tool: “MRSA says ‘No’ to Anti-Staph Penicillins.”

Rationale for Question: MRSA is a frequent concern in recurrent UTIs, and choosing the wrong antibiotic can have dire consequences.

Question 24

Clinical Vignette: A 70-year-old female patient with a recurrent UTI is found to have an infection due to Enterobacteriaceae. Which antibiotic would be ineffective for treating her condition?

A. Pivmecillinam
B. Trimethoprim-sulfamethoxazole
C. Amoxicillin or ampicillin
D. Fosfomycin

Answer 24

Correct Answer: A. Pivmecillinam

Explanation for Choices:

A: Pivmecillinam is not effective against most Enterobacteriaceae (Paragraph 1, Table 55.6).
B: Trimethoprim-sulfamethoxazole is effective against most Enterobacteriaceae (Paragraph 1, Table 55.6).
C: Amoxicillin or ampicillin can treat certain Enterobacteriaceae like Proteus mirabilis (Paragraph 1, Table 55.6).
D: Fosfomycin is effective against most Enterobacteriaceae (Paragraph 1, Table 55.6).
Memory Tool: “Pivot away from Pivmecillinam for Enterobacteriaceae.”

Rationale for Question: Proper antibiotic selection for Enterobacteriaceae is important due to their common presence in UTIs.

Question 25

Clinical Vignette: A 50-year-old male patient has a UTI, and the culture comes back positive for a Gram-negative pathogen. Which of the following antibiotics is not appropriate for treating Gram-negative pathogens?

A. First-generation cephalosporins
B. Amoxicillin with clavulanate
C. Antistaphylococcal penicillins
D. Aminoglycosides

Answer 25

Correct Answer: C. Antistaphylococcal penicillins

Explanation for Choices:

A: First-generation cephalosporins are effective against certain Gram-negative pathogens like Escherichia coli and P. mirabilis (Paragraph 1, Table 55.6).
B: Amoxicillin with clavulanate provides reliable coverage against several Gram-negative pathogens (Paragraph 1, Table 55.6).
C: Antistaphylococcal penicillins do not offer coverage against any Gram-negative pathogens (Paragraph 1, Table 55.6).
D: Aminoglycosides are effective against most Gram-negative pathogens (Paragraph 1, Table 55.6).
Memory Tool: “Anti-Staph is a Negative for Gram-Negatives.”

Rationale for Question: Understanding limitations in the antibiotic spectrum is essential for appropriate treatment of Gram-negative infections.

Question 26

Clinical Vignette: A 35-year-old female presents with a complicated UTI. The culture shows Pseudomonas aeruginosa. What third-generation cephalosporin would be effective against this pathogen?

A. Ceftriaxone
B. Ceftazidime
C. Neither
D. Both

Answer 26

Correct Answer: B. Ceftazidime

Explanation for Choices:

A: Ceftriaxone doesn’t provide effective coverage against Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
B: Ceftazidime does cover Pseudomonas aeruginosa (Paragraph 1, Table 55.6).
C: Incorrect, as Ceftazidime is effective.
D: Incorrect, as only Ceftazidime is effective.
Memory Tool: “Cefta-Zaps Pseudomonas.”

Rationale for Question: Differentiating between subclasses of third-generation cephalosporins is crucial in treating Gram-negative pathogens effectively.

Question 27

Clinical Vignette: A 60-year-old man is found to have a UTI with MRSA. Which antibiotic would be effective in treating this infection?

A. Vancomycin
B. Ampicillin with sulbactam
C. First-generation cephalosporins
D. Aztreonam

Answer 27

Correct Answer: A. Vancomycin

Explanation for Choices:

A: Vancomycin is effective against all Gram-positive pathogens, including MRSA (Paragraph 1, Table 55.6).
B: Ampicillin with sulbactam is not effective against MRSA (Paragraph 1, Table 55.6).
C: First-generation cephalosporins are not effective against MRSA (Paragraph 1, Table 55.6).
D: Aztreonam has no Gram-positive coverage, including MRSA (Paragraph 1, Table 55.6).
Memory Tool: “Vanquish MRSA with Vancomycin.”

Rationale for Question: MRSA is a significant concern due to its antibiotic resistance. Knowing which antibiotics are effective against it is crucial.

Question 28

Clinical Vignette: A patient presents with a UTI and is found to be infected with P. aeruginosa. Which antibiotic is NOT effective against P. aeruginosa?

A. Third-generation cephalosporins (ceftazidime)
B. Aztreonam
C. Fluoroquinolones
D. Fosfomycin

Answer 28

Correct Answer: D. Fosfomycin

Explanation for Choices:

A: Ceftazidime is effective against most Gram-negative pathogens, including P. aeruginosa (Paragraph 1, Table 55.6).
B: Aztreonam is effective against most Gram-negative pathogens, including P. aeruginosa (Paragraph 1, Table 55.6).
C: Fluoroquinolones are effective against most Gram-negative pathogens, including P. aeruginosa (Paragraph 1, Table 55.6).
D: Fosfomycin is not effective against P. aeruginosa (Paragraph 1, Table 55.6).
Memory Tool: “Don’t go FosFishing for P. aeruginosa.”

Rationale for Question: P. aeruginosa is a frequent Gram-negative pathogen in UTIs, and choosing an ineffective antibiotic could lead to treatment failure.

Question 29

Clinical Vignette: A 40-year-old male has a UTI due to a Gram-positive pathogen. Which of the following antibiotics should NOT be chosen?

A. Ampicillin with sulbactam
B. Second-generation cephalosporins (cefoxitin, cefotetan)
C. Aztreonam
D. Antistaphylococcal penicillins

Answer 29

Correct Answer: C. Aztreonam

Explanation for Choices:

A: Ampicillin with sulbactam provides effective coverage for some Gram-positive pathogens (Paragraph 1, Table 55.6).
B: Second-generation cephalosporins (cefoxitin, cefotetan) are effective against Streptococcus (Paragraph 1, Table 55.6).
C: Aztreonam has no Gram-positive coverage (Paragraph 1, Table 55.6).
D: Antistaphylococcal penicillins cover some Gram-positive pathogens like Streptococcus and Staphylococcus (Paragraph 1, Table 55.6).
Memory Tool: “Aztreonam Aces only Gram-Negative.”

Rationale for Question: For a UTI caused by a Gram-positive pathogen, it’s important to avoid antibiotics with no Gram-positive coverage.

Question 30

Clinical Vignette:
A 45-year-old male patient with a UTI is prescribed ampicillin. Three days later, he presents with a maculopapular rash.

Multiple-Choice Options:
A) This is an immediate hypersensitivity reaction
B) This could be a sign of Antimicrobial-associated pseudomembranous colitis (AAPMC)
C) This is not a hypersensitivity reaction
D) This is a result of allopurinol therapy

Answer 30

Correct Answer:
C) This is not a hypersensitivity reaction

In-Depth Explanation:

A: Immediate hypersensitivity reactions usually occur rapidly and are IgE-mediated. They are not typically maculopapular.
B: AAPMC usually presents with diarrhea, not a maculopapular rash.
C: Correct. A maculopapular rash with ampicillin is not a hypersensitivity reaction.
D: While ampicillin increases the risk of a rash with concomitant allopurinol therapy, this vignette doesn’t mention allopurinol use.
Memory Tool:
Remember “AMP - Allergy Misconception Problem” to recall that a maculopapular rash with ampicillin is not an allergic reaction.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Amoxicillin or ampicillin section)

Rationale:
Understanding the nature of adverse reactions to antibiotics like ampicillin is critical for proper patient management and avoids unnecessary discontinuation or switching of medications.

Question 31

Clinical Vignette:
A 55-year-old woman who previously experienced a delayed hypersensitivity reaction to penicillin needs treatment for a UTI.

Multiple-Choice Options:
A) Cephalosporins are strictly contraindicated
B) Cephalosporins can be used with caution
C) Cephalosporins should be the first choice
D) Cephalosporins must be avoided in all types of hypersensitivity to penicillin

Answer 31

Correct Answer:
B) Cephalosporins can be used with caution

In-Depth Explanation:

A: Cephalosporins are not strictly contraindicated in delayed hypersensitivity reactions to penicillins.
B: Correct. Cephalosporins may be used with caution in patients with delayed hypersensitivity reactions to penicillins.
C: They should not be the first choice due to cross-reactivity concerns.
D: Cephalosporins should only be avoided in immediate hypersensitivity to penicillins.
Memory Tool:
Think of “CephaloSecond” to remember that Cephalosporins can be a second choice in delayed penicillin hypersensitivity.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Cephalosporins section)

Rationale:
Knowing when cephalosporins can be safely used in patients with a history of penicillin allergy is essential for appropriate antibiotic selection.

Question 32

Clinical Vignette:
A 60-year-old male with pyelonephritis and impaired renal function is being considered for treatment with aminoglycosides.

Multiple-Choice Options:
A) Prescribe aminoglycosides as they are safe in renal impairment
B) Avoid aminoglycosides due to risk of ototoxicity only
C) Avoid aminoglycosides due to risk of ototoxicity and nephrotoxicity
D) Aminoglycosides can be prescribed with caution in conjunction with antidiabetic agents

Answer 32

Correct Answer:
C) Avoid aminoglycosides due to risk of ototoxicity and nephrotoxicity

In-Depth Explanation:

A: Incorrect, aminoglycosides are risky in patients with impaired renal function due to nephrotoxicity.
B: Ototoxicity is a concern, but not the only one. Nephrotoxicity is also a significant risk.
C: Correct, both ototoxicity and nephrotoxicity are adverse effects, making aminoglycosides a poor choice in this case.
D: Using aminoglycosides with antidiabetic agents is not specifically mentioned in this patient scenario.
Memory Tool:
Remember “AminNOglycosides in bad Kidneys & Ears” to recall that aminoglycosides should be avoided in renal impairment and for ototoxicity risks.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Aminoglycosides section)

Rationale:
Being aware of contraindications for aminoglycosides in renal impairment and understanding their adverse effects is crucial for patient safety.

Question 33

Clinical Vignette:
A 28-year-old pregnant woman presents with UTI symptoms. She inquires about fluoroquinolone treatment.

Multiple-Choice Options:
A) Prescribe fluoroquinolones as they are generally safe during pregnancy
B) Avoid fluoroquinolones due to their potential for arthropathic effects in children and pregnant patients
C) Prescribe fluoroquinolones but advise against concurrent antacid use
D) Fluoroquinolones can be prescribed but require frequent monitoring of glucose levels

Answer 33

Correct Answer:
B) Avoid fluoroquinolones due to their potential for arthropathic effects in children and pregnant patients

In-Depth Explanation:

A: Incorrect, fluoroquinolones are contraindicated in pregnancy due to arthropathic effects.
B: Correct, fluoroquinolones should be avoided in pregnant patients.
C: While true about antacids, this doesn’t address the contraindication in pregnancy.
D: Although fluoroquinolones can affect glucose levels, this is irrelevant in the context of a pregnant patient where the drug is contraindicated.
Memory Tool:
Think “Fluoroquino-lones are a no-go in mom and tot” to remember the contraindication during pregnancy.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Fluoroquinolones section)

Rationale:
Understanding contraindications is essential, especially in special populations like pregnant women, to avoid potentially harmful effects.

Question 34

Clinical Vignette:
A 55-year-old woman with a history of penicillin allergy is diagnosed with a UTI. She’s worried about the safety of other antibiotics.

Multiple-Choice Options:
A) Aztreonam is contraindicated in her case
B) Aztreonam has less than 1% incidence of cross-reactivity and may be used with caution
C) Aztreonam has a high rate of cross-reactivity with penicillins
D) Aztreonam should be avoided, as it is primarily used for respiratory tract infections

Answer 34

Correct Answer:
B) Aztreonam has less than 1% incidence of cross-reactivity and may be used with caution

In-Depth Explanation:

A: Incorrect. Aztreonam is not contraindicated for patients with penicillin allergies.
B: Correct. Aztreonam has less than 1% incidence of cross-reactivity with penicillin-allergic patients.
C: Incorrect. Aztreonam actually has a low rate of cross-reactivity with penicillins.
D: Incorrect. Aztreonam can be used for UTIs, not just respiratory tract infections.
Memory Tool:
“Aztre-No-Ram”: No ramming into trouble with aztreonam if you’re penicillin-allergic.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Aztreonam section)

Rationale:
Knowing safe antibiotic options for patients with common allergies like penicillin is critical for effective treatment planning.

Question 35

Clinical Vignette:
A 67-year-old male patient with renal insufficiency needs a UTI treatment. Nitrofurantoin is considered as an option.

Multiple-Choice Options:
A) Prescribe nitrofurantoin as renal function is not a significant concern
B) Avoid nitrofurantoin due to the low creatinine clearance
C) Prescribe nitrofurantoin but reduce the dosage
D) Prescribe nitrofurantoin but avoid concomitant use of magnesium

Answer 35

Correct Answer:
B) Avoid nitrofurantoin due to the low creatinine clearance

In-Depth Explanation:

A: Incorrect, renal function is a significant concern for nitrofurantoin.
B: Correct, nitrofurantoin should not be used in patients with low creatinine clearance (<50 mL/min).
C: Incorrect, dosage reduction does not alleviate the problem of low creatinine clearance.
D: While avoiding magnesium is a precaution, it doesn’t address the primary issue of renal insufficiency.
Memory Tool:
“50, then nifty”: If creatinine clearance is below 50 mL/min, nitrofurantoin is not a nifty option.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Nitrofurantoin section)

Rationale:
Understanding medication limitations based on renal function can prevent ineffective treatment and adverse reactions.

Question 36

Clinical Vignette:
A 38-year-old woman diagnosed with pyelonephritis is in her second trimester of pregnancy. The team is considering using an aminoglycoside.

Multiple-Choice Options:
A) Prescribe aminoglycosides without reservations
B) Avoid aminoglycosides due to potential ototoxicity and nephrotoxicity
C) Use aminoglycosides only for pyelonephritis during pregnancy
D) Use aminoglycosides but avoid them in patients with myasthenia gravis

Answer 36

Correct Answer:
C) Use aminoglycosides only for pyelonephritis during pregnancy

In-Depth Explanation:

A: Incorrect. Aminoglycosides are generally to be avoided in pregnant patients.
B: Incorrect. While ototoxicity and nephrotoxicity are concerns, they are not the primary issues in this case.
C: Correct. Aminoglycosides should only be used in pregnant patients for pyelonephritis.
D: Incorrect. Though it’s true that they should be used with caution in myasthenia gravis patients, this is not relevant to the clinical vignette.
Memory Tool:
“AminOnly for Pyelo”: Use Aminoglycosides only for pyelonephritis during pregnancy.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Aminoglycosides section)

Rationale:
Understanding when it’s safe to use aminoglycosides in pregnant women is essential for minimizing risks to both the mother and fetus.

Question 37

Clinical Vignette:
A 42-year-old man with diabetes and UTI is currently taking antidiabetic agents. Fluoroquinolones are considered for treatment.

Multiple-Choice Options:
A) Prescribe fluoroquinolones without any additional precautions
B) Monitor glucose levels closely while using fluoroquinolones
C) Avoid fluoroquinolones because of the patient’s diabetes
D) Prescribe fluoroquinolones but discontinue the antidiabetic agents

Answer 37

Correct Answer:
B) Monitor glucose levels closely while using fluoroquinolones

In-Depth Explanation:

A: Incorrect. Additional precautions related to glucose levels are needed.
B: Correct. Glucose levels need to be monitored closely when fluoroquinolones and antidiabetic agents are used concurrently.
C: Incorrect. Diabetes isn’t a contraindication for fluoroquinolones.
D: Incorrect. There is no need to discontinue antidiabetic agents, but monitoring is essential.
Memory Tool:
“Fluoro-Gluco”: With Fluoroquinolones, keep an eye on Glucose levels.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Fluoroquinolones section)

Rationale:
Monitoring glucose levels in diabetic patients on fluoroquinolones can prevent hypoglycemia or hyperglycemia, thus avoiding potential complications.

Question 38

Clinical Vignette:
A 29-year-old woman presents with symptoms of UTI. She also complains of a recurrent headache. Fosfomycin is being considered for treatment.

Multiple-Choice Options:
A) Prescribe fosfomycin without concern
B) Avoid fosfomycin due to her recurrent headaches
C) Prescribe fosfomycin but monitor for increased headache frequency
D) Use fosfomycin only for complicated UTIs

Answer 38

Correct Answer:
C) Prescribe fosfomycin but monitor for increased headache frequency

In-Depth Explanation:

A: Incorrect. Considering her recurrent headaches, monitoring is needed.
B: Incorrect. Headaches are not a contraindication for fosfomycin.
C: Correct. Headaches are a known adverse effect, so monitoring for increased frequency is advised.
D: Incorrect. Fosfomycin is not reserved for complicated UTIs only.

Question 39

Clinical Vignette:
A 45-year-old man with a UTI is also diagnosed with myasthenia gravis. Aminoglycosides are being considered as a treatment option.

Multiple-Choice Options:
A) Prescribe aminoglycosides with no further precautions
B) Avoid aminoglycosides in this patient
C) Prescribe aminoglycosides but closely monitor auditory function
D) Use aminoglycosides but monitor for neuromuscular blockade

Answer 39

Correct Answer:
B) Avoid aminoglycosides in this patient

In-Depth Explanation:

A: Incorrect. There are precautions to consider in this patient.
B: Correct. Aminoglycosides should be avoided in myasthenia gravis patients due to the potential for neuromuscular blockade.
C: Incorrect. Auditory function isn’t the primary concern here.
D: Incorrect. Monitoring doesn’t address the potential severe adverse effect.
Memory Tool:
“AminoGravis”: Aminoglycosides are a “grave” concern in myasthenia gravis due to neuromuscular blockade.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Aminoglycosides section)

Rationale:
It’s vital to understand the contraindications related to neuromuscular diseases like myasthenia gravis when considering aminoglycosides.

Question 40

Clinical Vignette:
A 56-year-old woman with a UTI is also taking warfarin for atrial fibrillation. She’s considering fluoroquinolones for her UTI.

Multiple-Choice Options:
A) Prescribe fluoroquinolones without monitoring warfarin levels
B) Avoid fluoroquinolones in this patient
C) Prescribe fluoroquinolones and closely monitor coagulation tests
D) Use fluoroquinolones but adjust the warfarin dose downward

Answer 40

Correct Answer:
C) Prescribe fluoroquinolones and closely monitor coagulation tests

In-Depth Explanation:

A: Incorrect. Warfarin levels can be affected by fluoroquinolones.
B: Incorrect. They can be used, but monitoring is essential.
C: Correct. Due to the interaction, coagulation tests must be closely monitored.
D: Incorrect. Adjusting the warfarin dose is premature without monitoring.
Memory Tool:
“FluoroCoag”: When on fluoroquinolones and warfarin, coagulation tests are a must.

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Fluoroquinolones section)

Rationale:
This question highlights the importance of being aware of drug interactions, particularly with anticoagulants like warfarin, to ensure patient safety.

Question 41

Clinical Vignette:
A 25-year-old woman reports frequent headaches and is prescribed fosfomycin for a UTI. She’s concerned about side effects.

Multiple-Choice Options:
A) Discontinue fosfomycin due to the risk of severe headaches
B) Continue fosfomycin without any precautions
C) Prescribe fosfomycin and advise monitoring for headaches
D) Switch to a different antibiotic

Answer 41

Correct Answer:
C) Prescribe fosfomycin and advise monitoring for headaches

In-Depth Explanation:

A: Incorrect. Headaches are a known but not severe adverse effect.
B: Incorrect. The patient should monitor for headaches.
C: Correct. Given her history, she should be advised to monitor for increased headaches.
D: Incorrect. Fosfomycin is not contraindicated, but monitoring is advisable.
Memory Tool:
“FosfoHead”: If a patient is already headachy, fosfomycin might make things throb a little more. Keep an eye out!

Specific Reference Citation:
Data from McEvoy GK, editor: American Hospital Formulary Service drug information, Bethesda, MD, 1995, American Society of Health-System Pharmacists (Paragraph: Fosfomycin section)

Rationale:
Understanding the risk profile of antibiotics like fosfomycin is important in managing patients who are predisposed to certain side effects.

Question 42

Clinical Vignette: A 35-year-old woman presents with symptoms suggestive of acute pyelonephritis. She is moderately ill but does not experience nausea or vomiting. What is the appropriate oral antibiotic treatment?

Multiple-choice options:

A) TMP-SMX DS 160-800 mg q12h for 7 days
B) Ciprofloxacin 500 mg q12h for 7 days
C) Levofloxacin 750 mg q24h for 5 days
D) Ampicillin and Gentamicin 1-2 g q6h for 10 days

Answer 42

Correct Answer:
C) Levofloxacin 750 mg q24h for 5 days

In-depth Explanation:

A) Incorrect. TMP-SMX DS is an option, but the frequency and dosage should be 160-800 mg q12h for 14 days.
B) Incorrect. Ciprofloxacin is also an option, but the treatment duration should be 7 days, not 5.
C) Correct. Levofloxacin 750 mg q24h for 5 days aligns with the table for outpatient, moderately ill patients with no nausea or vomiting.
D) Incorrect. Ampicillin and Gentamicin are recommended for inpatients with severe illness or possible sepsis.
Memory Tool:
Levo-5, Cipro-7, TMP-14: Levofloxacin for 5 days, Ciprofloxacin for 7 days, and TMP-SMX for 14 days for moderate illness without nausea or vomiting.

Reference Citation:
Paragraph 1, Table 55.11

Rationale for Importance:
Knowing the appropriate medication regimen for acute pyelonephritis is crucial for effective treatment and minimizing complications, especially in outpatient settings.

Question 43

Clinical Vignette: A 45-year-old woman is admitted with severe pyelonephritis and possible sepsis. What is the recommended parenteral treatment?

Multiple-choice options:

A) Ampicillin and gentamicin 1-2 g q6h for 7 days
B) Levofloxacin 500-750 mg q24h for 10-14 days
C) TMP-SMX DS 160-800 mg q12h for 14 days
D) Aztreonam 1 g q8h for 5 days

Answer 43

Correct Answer:
B) Levofloxacin 500-750 mg q24h for 10-14 days

In-depth Explanation:

A) Incorrect. Although Ampicillin and gentamicin can be used, the duration should be 10-14 days, not 7.
B) Correct. Levofloxacin 500-750 mg q24h for 10-14 days is appropriate for severely ill patients with possible sepsis.
C) Incorrect. TMP-SMX DS is recommended for moderately ill outpatients, not for severely ill inpatients.
D) Incorrect. Aztreonam is specifically recommended for pregnant women, not for the general population.
Memory Tool:
“Levo-Severe-14” to remember that Levofloxacin 500-750 mg q24h for 10-14 days is the choice for severe illness.

Reference Citation:
Paragraph 2, Table 55.11

Rationale for Importance:
Choosing the correct parenteral agent for severely ill patients can be a life-saving decision, especially in cases with sepsis.

Question 44

Clinical Vignette: A 26-year-old pregnant woman presents with symptoms indicative of acute pyelonephritis. What is the most suitable parenteral antibiotic regimen?

Multiple-choice options:

A) Ciprofloxacin 500 mg q12h for 7 days
B) Ampicillin and gentamicin 1-2 g q6h for 10-14 days
C) Levofloxacin 750 mg q24h for 5 days
D) Ceftriaxone 1 g q24h for 10-14 days

Answer 44

Correct Answer:
B) Ampicillin and gentamicin 1-2 g q6h for 10-14 days

In-depth Explanation:

A) Incorrect. Ciprofloxacin is contraindicated in pregnancy.
B) Correct. Ampicillin and gentamicin 1-2 g q6h for 10-14 days are the appropriate parenteral agents for pregnant women with acute pyelonephritis.
C) Incorrect. Levofloxacin is not recommended during pregnancy.
D) Incorrect. Ceftriaxone is not listed as a recommended treatment for pregnant women with acute pyelonephritis in the table.
Memory Tool:
“Amp-Gent Baby” to remember that Ampicillin and Gentamicin are safe for babies (i.e., during pregnancy).

Reference Citation:
Paragraph 3, Table 55.11

Rationale for Importance:
In pregnancy, proper treatment is critical both for the health of the mother and the developing fetus. Knowing the appropriate antibiotics can be lifesaving for both.

Question 45

Clinical Vignette: A 68-year-old woman with acute pyelonephritis also has compromised renal function. What should be considered regarding her antibiotic dosing?

Multiple-choice options:

A) Increase the dosage for maximum efficacy
B) No need for any dosage adjustment
C) Reduce the frequency per dose
D) All dosages should be adjusted for renal function

Answer 45

Correct Answer:
D) All dosages should be adjusted for renal function

In-depth Explanation:

A) Incorrect. Increasing the dosage without adjusting for renal function can lead to toxicity.
B) Incorrect. Patients with compromised renal function do require dosage adjustments.
C) Incorrect. Reducing the frequency alone may not be sufficient.
D) Correct. All dosages should be adjusted based on renal function to ensure both safety and efficacy.
Memory Tool:
“Renal-Adjust” to remember that renal function requires dosage adjustments.

Reference Citation:
Footnote ‘e’, Table 55.11

Rationale for Importance:
Failure to adjust drug dosages in patients with compromised renal function can lead to ineffective treatment or toxicity, making this an important consideration in patient care.

Question 46

Clinical Vignette: A 42-year-old woman comes in with moderate pyelonephritis symptoms but without nausea or vomiting. In addition to her oral antibiotic regimen, what could be considered as an initial treatment?

Multiple-choice options:

A) A consolidated 24-hour dose of aminoglycoside
B) A one-time intravenous dose of 2g of ceftriaxone
C) No additional treatment is necessary
D) A one-time intravenous dose of 1g of ceftriaxone

Answer 46

Correct Answer:
D) A one-time intravenous dose of 1g of ceftriaxone

In-depth Explanation:

A) Correct as an option. An initial 1-time consolidated 24-hour dose of an aminoglycoside may be given.
B) Incorrect. The recommended initial dose of ceftriaxone is 1g, not 2g.
C) Incorrect. An initial dose of a long-acting parenteral antimicrobial is recommended.
D) Correct. A one-time intravenous dose of 1g of ceftriaxone is also recommended as an initial treatment.

Question 47

Clinical Vignette: A 50-year-old woman is diagnosed with acute pyelonephritis. Local resistance rates to fluoroquinolones are unknown. What should be the treatment consideration for fluoroquinolones?

Multiple-choice options:

A) Use fluoroquinolones without hesitation
B) Use only if resistance is known to exceed 20%
C) Avoid using fluoroquinolones
D) Use only if resistance is not known to exceed 10%

Answer 47

Correct Answer:
D) Use only if resistance is not known to exceed 10%

In-depth Explanation:

A) Incorrect. Should not be used without considering local resistance rates.
B) Incorrect. If resistance exceeds 20%, fluoroquinolones are generally contraindicated.
C) Incorrect. Fluoroquinolones may be used if resistance rates are favorable.
D) Correct. Can be used in areas where the prevalence of resistance is not known to exceed 10%.
Memory Tool:
“Fluoro-10” to remember that fluoroquinolones can be considered if resistance is not known to exceed 10%.

Reference Citation:
Footnote ‘c’, Table 55.11

Rationale for Importance:
Resistance to fluoroquinolones can vary by location, and proper antibiotic stewardship requires knowing when these agents are appropriate.

Question 48

Clinical Vignette:
A 28-year-old pregnant woman in her second trimester presents with symptoms of a urinary tract infection. You’re considering which oral antimicrobial agent to prescribe.

Multiple Choice Options:
A) Erythromycin
B) Nitrofurantoin
C) Trimethoprim
D) Cefaclor

Answer 48

Correct Answer:
D) Cefaclor

In-depth Explanation:

A) Erythromycin: This agent should be avoided as it is associated with maternal cholestatic jaundice.
B) Nitrofurantoin: While it is generally safe, it may result in hemolytic anemia in patients with G6PD deficiency. Moreover, it’s best used in the first two trimesters.
C) Trimethoprim: Should be avoided as it inhibits folic acid metabolism and is teratogenic, especially concerning neural tube defects.
D) Cefaclor: This is a cephalosporin considered safe for use in pregnancy and is somewhat more effective against gram-negative organisms.
Memory Tool:
Think “Cef for Safe” - Cefaclor is safe and more effective against gram-negative organisms.

Specific Reference Citation:
Modified from Schaeffer AJ: Urinary tract infections. In Gillenwater JY, Grayhack JT, Howards SS, et al., editors: Adult and pediatric urology, Philadelphia, 2002, Lippincott Williams & Wilkins, pp 211–272 (Table 55.13).

Rationale:
The question helps distinguish between oral antimicrobial agents that are safe in pregnancy and those that should be avoided, particularly when treating UTIs. Knowing this ensures safer treatment options for pregnant patients.

Question 49

Clinical Vignette:
A 35-year-old pregnant woman comes to your clinic with UTI symptoms. She mentions she’s allergic to cephalosporins. What is another safe antimicrobial option?

Multiple Choice Options:
A) Penicillin V
B) Fluoroquinolones
C) Chloramphenicol
D) Tetracyclines

Answer 49

Correct Answer:
A) Penicillin V

In-depth Explanation:

A) Penicillin V: This is a penicillin considered safe during pregnancy and is used less frequently but achieves excellent urinary levels.
B) Fluoroquinolones: Should be avoided as they may cause damage to immature cartilage.
C) Chloramphenicol: Should be avoided as it is associated with “gray baby” syndrome.
D) Tetracyclines: Should be avoided as they may cause acute liver decompensation in the mother and inhibit new bone growth in the fetus.
Memory Tool:
“V for Victory” - Penicillin V is victorious as a safe alternative to cephalosporins in pregnancy.

Specific Reference Citation:
Same source as above (Table 55.13).

Rationale:
The question assesses your ability to identify a safe alternative to cephalosporins for UTIs in pregnant women.

Question 50

Clinical Vignette:
A pregnant woman in her third trimester is diagnosed with a UTI. She has no known allergies. You need to decide the dosage of amoxicillin to prescribe.

Multiple Choice Options:
A) 500 mg four times daily
B) 250 mg three times daily
C) 100 mg four times daily
D) 750 mg twice daily

Answer 50

Correct Answer:
B) 250 mg three times daily

In-depth Explanation:

A) 500 mg four times daily: This dosage is for ampicillin, not amoxicillin.
B) 250 mg three times daily: This is the correct dosage for amoxicillin in pregnancy. It is considered safe and effective.
C) 100 mg four times daily: This dosage is incorrect for amoxicillin.
D) 750 mg twice daily: This dosage is also incorrect for amoxicillin.
Memory Tool:
“Third Trimester, Three Times” - In the third trimester, prescribe amoxicillin 250 mg three times daily.

Specific Reference Citation:
Same source as above (Table 55.13).

Rationale:
The question tests your knowledge of the correct dosage of amoxicillin for treating UTIs in pregnant women.

Question 51

Clinical Vignette:
A 32-year-old pregnant woman in her first trimester is diagnosed with a UTI. She has G6PD deficiency. What should you consider regarding the prescription of Nitrofurantoin?

Multiple Choice Options:
A) May cause neural tube defects
B) No additional risks
C) May result in hemolytic anemia
D) May cause acute liver decompensation

Answer 51

Correct Answer:
C) May result in hemolytic anemia

In-depth Explanation:

A) May cause neural tube defects: Incorrect, that’s a risk with trimethoprim.
B) No additional risks: Incorrect, Nitrofurantoin may result in hemolytic anemia in patients with G6PD deficiency.
C) May result in hemolytic anemia: Correct, Nitrofurantoin may lead to hemolytic anemia in G6PD-deficient patients.
D) May cause acute liver decompensation: Incorrect, that’s a risk with tetracyclines.
Memory Tool:
“Nitro-G6PD-No” - Nitrofurantoin and G6PD deficiency can lead to hemolytic anemia.

Specific Reference Citation:
Same source as above (Table 55.13).

Rationale:
This question tests your awareness of specific contraindications regarding the use of Nitrofurantoin in special populations, such as those with G6PD deficiency.

Question 52

Clinical Vignette:
A pregnant woman comes to your clinic, concerned about the risk of medications causing birth defects. She specifically asks about antibiotics that might be teratogenic.

Multiple Choice Options:
A) Penicillin V
B) Erythromycin
C) Trimethoprim
D) Cephalexin

Answer 52

Correct Answer:
C) Trimethoprim

In-depth Explanation:

A) Penicillin V: Considered safe in pregnancy, achieves excellent urinary levels.
B) Erythromycin: Should be avoided due to the risk of maternal cholestatic jaundice, but not known for teratogenic effects.
C) Trimethoprim: Should be avoided as it inhibits folic acid metabolism and is thus teratogenic, especially concerning neural tube defects.
D) Cephalexin: Extensively used and considered safe in pregnancy.
Memory Tool:
“Trim the Risk” - Trimethoprim should be avoided to trim the risk of teratogenic effects.

Specific Reference Citation:
Same source as above (Table 55.13).

Rationale:
The question targets your knowledge regarding antibiotics that pose a teratogenic risk, crucial for safely treating pregnant women.

Question 53

Clinical Vignette:
A 30-year-old pregnant woman with liver disease is diagnosed with a UTI. She is concerned about liver-related side effects of antibiotics. Which antibiotic should she particularly avoid?

Multiple Choice Options:
A) Tetracyclines
B) Ampicillin
C) Cefaclor
D) Nitrofurantoin

Answer 53

Correct Answer:
A) Tetracyclines

In-depth Explanation:

A) Tetracyclines: May cause acute liver decompensation in the mother and should be avoided, especially in those with liver disease.
B) Ampicillin: Extensively used and considered safe in pregnancy.
C) Cefaclor: Somewhat more effective against gram-negative organisms and considered safe.
D) Nitrofurantoin: May be used during the first two trimesters but has a risk of hemolytic anemia in G6PD-deficient patients, not liver disease.
Memory Tool:
“Tetra-NO-Liver” - Avoid tetracyclines in liver disease due to risk of liver decompensation.

Specific Reference Citation:
Same source as above (Table 55.13).

Rationale:
This question emphasizes the importance of avoiding certain antibiotics in pregnant women with specific comorbidities, like liver disease.

Question 54

A 48-year-old male undergoes a nephrectomy for a benign tumor. The surgery involves opening into the urinary tract under controlled conditions. How would you classify the wound?

A) Class I/clean
B) Class II/clean-contaminated
C) Class III/contaminated
D) Class IV/dirty

Answer 54

Correct Answer: B) Class II/clean-contaminated

Explanation:

A) Class I/clean: This classification applies to uninfected operative wounds without entry into the pulmonary, GI, or GU systems.
B) Class II/clean-contaminated: Correct. Entry into pulmonary, GI, or GU under controlled conditions; no other contamination. In this scenario, the surgery involved controlled entry into the urinary tract, thus fitting the Class II description.
C) Class III/contaminated: This is for infected stone procedures or use of bowel segments.
D) Class IV/dirty: Applies to open trauma or abscesses.
Memory Tool: “Two Cs: Class II is Clean-Contaminated, like a Controlled Cut into GU.”

Reference Citation: Modified from Mangram, AJ, et al, 1999. Paragraph: Class II/clean-contaminated

Rationale: Understanding wound classifications is essential for postoperative care and antibiotic prophylaxis.

Question 55

Question 2: Antibiotic Prophylaxis

You’re performing a prosthesis implantation for a patient with a history of MRSA colonization. Which antibiotic would you most likely consider for perioperative prophylaxis?

A) Penicillin
B) Ciprofloxacin
C) Vancomycin
D) Amoxicillin

Answer 55

Correct Answer: C) Vancomycin

Explanation:

A) Penicillin: Generally ineffective against MRSA.
B) Ciprofloxacin: While it can be used for some GU infections, it’s not the best choice for MRSA.
C) Vancomycin: Correct. Due to increasing resistance and MRSA colonization, many surgeons opt for vancomycin perioperatively for prosthesis implantations.
D) Amoxicillin: Generally not effective against MRSA.
Memory Tool: “MRSA -> M(V)ancomycin”

Reference Citation: Modified from Mangram, AJ, et al, 1999. Paragraph: Prosthesis Implantation.

Rationale: Knowing the right antibiotic for specific cases helps in minimizing postoperative complications.

Question 56

A patient is scheduled for an inguinal hernia repair. According to wound classifications, how would the wound from this procedure be classified?

A) Class I/clean
B) Class II/clean-contaminated
C) Class III/contaminated
D) Class IV/dirty

Answer 56

Correct Answer: A) Class I/clean

Explanation:

A) Class I/clean: Correct. Inguinal procedures for noninfectious indications fall under Class I/clean wounds.
B) Class II/clean-contaminated: Typically involves entry into pulmonary, GI, or GU systems under controlled conditions; not applicable here.
C) Class III/contaminated: Involves infected stone procedures or use of bowel segments.
D) Class IV/dirty: Includes open trauma or abscesses.
Memory Tool: “Inguinal Ignition is Class I/clean, and that’s no illusion.”

Reference Citation: Modified from Mangram, AJ, et al, 1999. Paragraph: Class I/clean.

Rationale: Understanding wound classifications aids in optimizing surgical outcomes and postoperative management.

Question 57

A patient undergoes a percutaneous nephrolithotomy (PCNL) for a struvite stone. What would be the wound classification for this procedure?

A) Class I/clean
B) Class II/clean-contaminated
C) Class III/contaminated
D) Class IV/dirty

Answer 57

Correct Answer: C) Class III/contaminated

Explanation:

A) Class I/clean: Uninfected operative wounds without entry into specific body systems.
B) Class II/clean-contaminated: Controlled entry into pulmonary, GI, or GU systems; not applicable here.
C) Class III/contaminated: Correct. This involves infected stone procedures like a PCNL on struvite stones.
D) Class IV/dirty: Involves open trauma or abscesses.
Memory Tool: “PCNL on struvite = 3 pieces of contamination.”

Reference Citation: Modified from Mangram, AJ, et al, 1999. Paragraph: Class III/contaminated.

Rationale: Identifying the level of wound contamination is vital for managing risks and postoperative care.

Question 58

A patient is admitted for debridement of an abscess. What wound classification is most appropriate for this case?

A) Class I/clean
B) Class II/clean-contaminated
C) Class III/contaminated
D) Class IV/dirty

Answer 58

orrect Answer: D) Class IV/dirty

Explanation:

A) Class I/clean: This is for uninfected operative wounds, not applicable here.
B) Class II/clean-contaminated: Involves controlled entry into specific body systems; not applicable.
C) Class III/contaminated: For infected stone procedures or use of bowel segments.
D) Class IV/dirty: Correct. This involves open trauma or abscesses, as is the case for debridement.
Memory Tool: “Debridement gets a D, and that’s for dirty.”

Reference Citation: Modified from Mangram, AJ, et al, 1999. Paragraph: Class IV/dirty.

Rationale: Recognizing a Class IV wound helps guide perioperative care, including antibiotic selection and wound management.

Question 59

According to best practices, antibiotic prophylaxis for prosthesis implantation should cover which type of organisms?

A) GI organisms
B) Likely skin organisms
C) Respiratory organisms
D) Bloodborne pathogens

Answer 59

Correct Answer: B) Likely skin organisms

Explanation:

A) GI organisms: These are typically not a focus for prosthesis implantation.
B) Likely skin organisms: Correct. Prophylaxis should cover likely skin organisms.
C) Respiratory organisms: Not the target for this surgical procedure.
D) Bloodborne pathogens: While important, they are not the primary focus for prosthesis implantation.
Memory Tool: “Skin is in when you’re implanting prostheses.”

Reference Citation: Modified from Mangram, AJ, et al, 1999. Paragraph: Prosthesis Implantation.

Rationale: The right choice of antibiotic coverage is crucial to minimize postoperative infections.

Question 60

Clinical Vignette: A 60-year-old male presents to the clinic for a urological procedure. He has a total hip replacement done over three years ago with no other host risk factors. What is the antimicrobial prophylaxis recommended for him?

Options:
A) Oral quinolone
B) Ampicillin, 2 g IV
C) Not recommended empirically
D) Vancomycin, 1 g IV

Answer 60

Correct Answer: C) Not recommended empirically

Explanation:

A) Oral quinolone is recommended for patients with a total joint replacement inserted <2 yr ago or aberrant host factors.
B) Ampicillin, 2 g IV is also recommended for the same patient group as option A.
C) For patients with a total joint inserted >2 yr ago and no host risk factors, antimicrobial prophylaxis is not recommended empirically.
D) Vancomycin can be substituted if there’s an ampicillin allergy but applies to the same patient group as option A.
Memory Tool: Total joint “Too old (>2 yrs)? Too bad, no antibiotics!”

Reference Citation: American Urological Association and American Academy of Orthopaedic Surgeons: Antibiotic prophylaxis for urological patients with total joint replacements. J Urol 169:1796–1797, 2003 (Table 55.17)

Rationale: Understanding antibiotic prophylaxis in urological procedures for patients with orthopedic hardware is essential to prevent unnecessary antimicrobial resistance and complications.

Question 61

Clinical Vignette: A 45-year-old female with a total knee replacement inserted 1.5 years ago and an ampicillin allergy is scheduled for a urologic procedure. What would be an appropriate antimicrobial substitution?

Options:
A) Oral quinolone
B) Gentamicin, 1.5 mg/kg IV
C) Vancomycin, 1 g IV
D) No antibiotic necessary

Answer 61

Correct Answer: C) Vancomycin, 1 g IV

Explanation:

A) Oral quinolone could be an option but is not a direct substitute for ampicillin.
B) Gentamicin is not a standalone option; it is given with ampicillin.
C) Vancomycin, 1 g IV over 1–2 h before the procedure is the recommended substitution if there’s an ampicillin allergy.
D) Given her recent knee replacement and allergy, she does require antibiotic prophylaxis.
Memory Tool: “Vanco-very good substitute for Ampicillin allergy.”

Reference Citation: American Urological Association and American Academy of Orthopaedic Surgeons: Antibiotic prophylaxis for urological patients with total joint replacements. J Urol 169:1796–1797, 2003 (Table 55.17)

Rationale: Being able to substitute antibiotics effectively for allergic patients is crucial for reducing surgical site infections.