📌Introduction
Antibiotics are an important topic in pharmacology and are frequently studied by pharmacy students for competitive and university examinations. Antibiotics are medicines used to treat bacterial infections by either killing bacteria or stopping their growth.
Different antibiotics act on different bacterial targets. Some inhibit cell-wall synthesis, while others interfere with protein synthesis, DNA replication, RNA synthesis, or folate metabolism. Understanding these mechanisms makes it easier to remember the classification, uses, and important adverse effects of antibiotics.
In this post, we have included 30 important multiple-choice questions (MCQs) on antibiotics, covering their classification, mechanism of action, uses, adverse effects, and antibiotic resistance. Each question has four options, the correct answer, and a simple explanation to help pharmacy students revise the topic quickly.
These MCQs can be useful for B.Pharm students, pharmacy entrance examinations, GPAT preparation, drug inspector exams, pharmacist exams, and other pharmacy competitive examinations.
🧬 MCQs on Antibiotics
1. Antibiotics are used to treat:
A) Viral infections
B) Bacterial infections
C) Fungal infections
D) Parasitic infections
✔ Answer: B) Bacterial infections
➜ Explanation: Antibiotics act only against bacteria.
2. Which is a bactericidal drug?
A) Penicillin
B) Tetracycline
C) Erythromycin
D) Chloramphenicol
✔ Answer: A) Penicillin
➜ Explanation: It kills bacteria by inhibiting cell wall synthesis.
3. Penicillin acts by inhibiting:
A) Protein synthesis
B) DNA synthesis
C) Cell wall synthesis
D) Metabolism
✔ Answer: C) Cell wall synthesis
4. Tetracycline inhibits:
A) DNA synthesis
B) Protein synthesis
C) Cell wall synthesis
D) RNA synthesis
✔ Answer: B) Protein synthesis
5. Ciprofloxacin acts on:
A) Ribosome
B) DNA gyrase
C) Cell wall
D) Enzymes
✔ Answer: B) DNA gyrase
6. Sulfonamides act as:
A) Protein inhibitors
B) Cell wall inhibitors
C) Antimetabolites
D) Hormones
✔ Answer: C) Antimetabolites
7. Which antibiotic is used in tuberculosis?
A) Amoxicillin
B) Rifampicin
C) Ibuprofen
D) Paracetamol
✔ Answer: B) Rifampicin
8. Macrolides act on:
A) Cell wall
B) Protein synthesis
C) DNA
D) Hormones
✔ Answer: B) Protein synthesis
9. Aminoglycosides are:
A) Bacteriostatic
B) Bactericidal
C) Antifungal
D) Antiviral
✔ Answer: B) Bactericidal
10. Chloramphenicol inhibits:
A) 30S ribosome
B) 50S ribosome
C) DNA
D) Cell wall
✔ Answer: B) 50S ribosome
11. Which antibiotic causes teeth discoloration?
A) Penicillin
B) Tetracycline
C) Ciprofloxacin
D) Rifampicin
✔ Answer: B) Tetracycline
12. Which is NOT an antibiotic?
A) Penicillin
B) Ciprofloxacin
C) Paracetamol
D) Rifampicin
✔ Answer: C) Paracetamol
13. Antibiotics should be avoided in:
A) Bacterial infection
B) Viral infection
C) Fever
D) Pain
✔ Answer: B) Viral infection
14. Resistance occurs due to:
A) Proper use
B) Overuse
C) Correct dose
D) Full course
✔ Answer: B) Overuse
15. Which inhibits DNA replication?
A) Penicillin
B) Ciprofloxacin
C) Tetracycline
D) Erythromycin
✔ Answer: B) Ciprofloxacin
16. Erythromycin belongs to:
A) Penicillin
B) Macrolide
C) Aminoglycoside
D) Tetracycline
✔ Answer: B) Macrolide
17. Which is bacteriostatic?
A) Penicillin
B) Aminoglycosides
C) Tetracycline
D) Cephalosporin
✔ Answer: C) Tetracycline
18. Cephalosporins act on:
A) Protein
B) Cell wall
C) DNA
D) RNA
✔ Answer: B) Cell wall
19. Superinfection is due to:
A) Low dose
B) Destruction of normal flora
C) High immunity
D) Infection
✔ Answer: B) Destruction of normal flora
20. Antibiotics may cause:
A) Allergy
B) Growth
C) Energy
D) Sleep
✔ Answer: A) Allergy
21. Which is broad-spectrum antibiotic?
A) Penicillin G
B) Tetracycline
C) Rifampicin
D) Vancomycin
✔ Answer: B) Tetracycline
22. Which is narrow spectrum?
A) Penicillin G
B) Tetracycline
C) Chloramphenicol
D) Ciprofloxacin
✔ Answer: A) Penicillin G
23. Fluoroquinolones act on:
A) DNA
B) Protein
C) Cell wall
D) Metabolism
✔ Answer: A) DNA
24. Which antibiotic is nephrotoxic?
A) Aminoglycosides
B) Penicillin
C) Tetracycline
D) Macrolide
✔ Answer: A) Aminoglycosides
25. Which is used in UTI?
A) Ciprofloxacin
B) Insulin
C) Aspirin
D) Vitamin D
✔ Answer: A) Ciprofloxacin
26. Which causes ototoxicity?
A) Aminoglycosides
B) Penicillin
C) Macrolides
D) Sulfonamides
✔ Answer: A) Aminoglycosides
27. Which is a macrolide?
A) Erythromycin
B) Penicillin
C) Ciprofloxacin
D) Tetracycline
✔ Answer: A) Erythromycin
28. Which antibiotic affects bone growth?
A) Tetracycline
B) Penicillin
C) Rifampicin
D) Amoxicillin
✔ Answer: A) Tetracycline
29. Antibiotics act on:
A) Viruses
B) Bacteria
C) Fungi
D) Parasites
✔ Answer: B) Bacteria
30. Best use of antibiotics:
A) Viral fever
B) Bacterial infection
C) Pain
D) Diabetes
✔ Answer: B) Bacterial infection
📝 Conclusion
Antibiotics are an important part of pharmacology, and understanding their classification, mechanism of action, uses, and adverse effects can make exam preparation much easier. Remembering the main drug targets—such as cell wall, 30S ribosome, 50S ribosome, DNA, RNA, and folate synthesis—is especially helpful for solving MCQs.
Regular practice of MCQs can help you identify important concepts, improve recall, and prepare more effectively for pharmacy examinations. Revise the explanations along with the answers rather than simply memorizing the correct options.
Keep practicing, revise regularly, and focus on understanding the mechanism of each antibiotic class.
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