6̇ Antimicrobials (12 questions)
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
Answer: B
Explanation: Beta-lactams inhibit bacterial cell wall synthesis by binding to penicillin-binding
proteins.
2. Which generation of cephalosporins is most effective against Pseudomonas aeruginosa?
A) First
B) Second
C) Third
D) Fourth
Answer: D
Explanation: Fourth-generation cephalosporins like cefepime are effective against
Pseudomonas.
3. Vancomycin is the drug of choice for:
A) MRSA infections
B) VRE infections
C) UTI
D) Syphilis
Answer: A
Explanation: Vancomycin is first-line for MRSA due to its gram-positive spectrum.
4. What is the peak concern with aminoglycosides?
A) Stevens-Johnson syndrome
B) Hepatotoxicity
C) Ototoxicity and nephrotoxicity
D) Anemia
Answer: C
Explanation: Aminoglycosides are known for nephrotoxicity and ototoxicity.
5. What mineral interactions reduce the absorption of tetracyclines?
A) Sodium
B) Potassium
C) Calcium, iron, magnesium
D) Phosphate
Answer: C
Explanation: Tetracyclines chelate with these minerals, reducing efficacy.
, 6. Macrolides can inhibit which hepatic enzyme system?
A) CYP1A2
B) CYP2D6
C) CYP3A4
D) CYP2C19
Answer: C
Explanation: Erythromycin and clarithromycin are strong CYP3A4 inhibitors.
7. Which antibiotic is associated with Clostridioides difficile colitis?
A) Metronidazole
B) Clindamycin
C) Nitrofurantoin
D) Ciprofloxacin
Answer: B
Explanation: Clindamycin is highly associated with C. diff.
8. Linezolid requires weekly monitoring of which lab value?
A) Liver enzymes
B) Platelet count
C) BUN
D) Calcium
Answer: B
Explanation: Linezolid may cause thrombocytopenia with prolonged use.
9. Sulfonamides inhibit:
A) Bacterial DNA gyrase
B) Folic acid synthesis
C) Ribosomal activity
D) Protein folding
Answer: B
Explanation: Sulfonamides inhibit folic acid synthesis, crucial for bacterial DNA.
10. Fluoroquinolones carry a black box warning for:
A) Seizures
B) Arrhythmias
C) Tendon rupture
D) Renal failure
Answer: C
Explanation: Tendon rupture is a serious risk, especially in older adults.
11. What is the mechanism of daptomycin?
A) DNA synthesis inhibition
B) Membrane depolarization
C) Folate synthesis inhibition
D) Protein synthesis inhibition
Answer: B
Explanation: Daptomycin causes rapid depolarization of the membrane potential.