NURS 5334 ANTIMICROBIAL EXAM
PREP
Practice Questions with Answers &
Clinical Rationales
### Pharmacodynamics, Resistance, and Stewardship
**1. What is the primary mechanism of action of beta-lactam
antibiotics like penicillin?**
- A) Inhibits protein synthesis
- B) Inhibits cell wall synthesis
- C) Alters DNA replication
- D) Blocks folic acid synthesis
**Correct Answer: B) Inhibits cell wall synthesis**
,**Rationale:** Beta-lactam antibiotics inhibit bacterial cell wall
synthesis by binding to penicillin-binding proteins (PBPs) and inhibiting
transpeptidases, enzymes that cross-link peptidoglycan chains. This
weakens the cell wall, causing bacteria to take up excessive amounts of
water and rupture. They are bactericidal .
---
**2. Which antibiotic class inhibits bacterial protein synthesis by
binding to the 50S ribosomal subunit?**
- A) Tetracyclines
- B) Aminoglycosides
- C) Macrolides
- D) Fluoroquinolones
**Correct Answer: C) Macrolides**
**Rationale:** Macrolides (azithromycin, clarithromycin, erythromycin)
bind to the 50S ribosomal subunit, inhibiting bacterial protein synthesis.
They are primarily bacteriostatic agents. Tetracyclines bind to the 30S
subunit, aminoglycosides bind to the 30S subunit as well, and
fluoroquinolones inhibit DNA synthesis .
---
,**3. Which generation of cephalosporins is most effective against
Pseudomonas aeruginosa?**
- A) First generation
- B) Second generation
- C) Third generation
- D) Fourth generation
**Correct Answer: D) Fourth generation**
**Rationale:** Fourth-generation cephalosporins, such as cefepime,
have enhanced activity against Gram-negative organisms including
Pseudomonas aeruginosa. They have greater stability against beta-
lactamases and better penetration through the outer membrane of
Gram-negative bacteria compared to earlier generations .
---
**4. Vancomycin is the drug of choice for which infection?**
- A) Urinary tract infections
- B) Syphilis
- C) MRSA infections
- D) VRE infections
, **Correct Answer: C) MRSA infections**
**Rationale:** Vancomycin is a glycopeptide antibiotic that inhibits cell
wall synthesis and is the drug of choice for methicillin-resistant
Staphylococcus aureus (MRSA) infections. It is not effective against VRE
(vancomycin-resistant enterococci), which require alternative agents
like linezolid or daptomycin .
---
**5. What is the peak concern with aminoglycoside antibiotics?**
- A) Stevens-Johnson syndrome
- B) Hepatotoxicity
- C) Ototoxicity and nephrotoxicity
- D) Anemia
**Correct Answer: C) Ototoxicity and nephrotoxicity**
**Rationale:** Aminoglycosides (gentamicin, tobramycin, amikacin) are
associated with significant ototoxicity (damage to the eighth cranial
nerve causing hearing loss and vestibular dysfunction) and
nephrotoxicity (acute tubular necrosis). These adverse effects are
related to drug accumulation in the renal cortex and inner ear.
Therapeutic drug monitoring is essential .
PREP
Practice Questions with Answers &
Clinical Rationales
### Pharmacodynamics, Resistance, and Stewardship
**1. What is the primary mechanism of action of beta-lactam
antibiotics like penicillin?**
- A) Inhibits protein synthesis
- B) Inhibits cell wall synthesis
- C) Alters DNA replication
- D) Blocks folic acid synthesis
**Correct Answer: B) Inhibits cell wall synthesis**
,**Rationale:** Beta-lactam antibiotics inhibit bacterial cell wall
synthesis by binding to penicillin-binding proteins (PBPs) and inhibiting
transpeptidases, enzymes that cross-link peptidoglycan chains. This
weakens the cell wall, causing bacteria to take up excessive amounts of
water and rupture. They are bactericidal .
---
**2. Which antibiotic class inhibits bacterial protein synthesis by
binding to the 50S ribosomal subunit?**
- A) Tetracyclines
- B) Aminoglycosides
- C) Macrolides
- D) Fluoroquinolones
**Correct Answer: C) Macrolides**
**Rationale:** Macrolides (azithromycin, clarithromycin, erythromycin)
bind to the 50S ribosomal subunit, inhibiting bacterial protein synthesis.
They are primarily bacteriostatic agents. Tetracyclines bind to the 30S
subunit, aminoglycosides bind to the 30S subunit as well, and
fluoroquinolones inhibit DNA synthesis .
---
,**3. Which generation of cephalosporins is most effective against
Pseudomonas aeruginosa?**
- A) First generation
- B) Second generation
- C) Third generation
- D) Fourth generation
**Correct Answer: D) Fourth generation**
**Rationale:** Fourth-generation cephalosporins, such as cefepime,
have enhanced activity against Gram-negative organisms including
Pseudomonas aeruginosa. They have greater stability against beta-
lactamases and better penetration through the outer membrane of
Gram-negative bacteria compared to earlier generations .
---
**4. Vancomycin is the drug of choice for which infection?**
- A) Urinary tract infections
- B) Syphilis
- C) MRSA infections
- D) VRE infections
, **Correct Answer: C) MRSA infections**
**Rationale:** Vancomycin is a glycopeptide antibiotic that inhibits cell
wall synthesis and is the drug of choice for methicillin-resistant
Staphylococcus aureus (MRSA) infections. It is not effective against VRE
(vancomycin-resistant enterococci), which require alternative agents
like linezolid or daptomycin .
---
**5. What is the peak concern with aminoglycoside antibiotics?**
- A) Stevens-Johnson syndrome
- B) Hepatotoxicity
- C) Ototoxicity and nephrotoxicity
- D) Anemia
**Correct Answer: C) Ototoxicity and nephrotoxicity**
**Rationale:** Aminoglycosides (gentamicin, tobramycin, amikacin) are
associated with significant ototoxicity (damage to the eighth cranial
nerve causing hearing loss and vestibular dysfunction) and
nephrotoxicity (acute tubular necrosis). These adverse effects are
related to drug accumulation in the renal cortex and inner ear.
Therapeutic drug monitoring is essential .
