Free Antimicrobial Drugs MCQs with Answers

• A. It inhibits bacterial cell wall synthesis
• B. It blocks bacterial folic acid absorption
• C. It prevents viral nucleic acid release
• D. It stops fungal ergosterol formation

Explanation: Beta-lactam antibiotics bind penicillin-binding proteins and inhibit peptidoglycan cross-linking, causing bacterial cell wall rupture.

• A. Overgrowth of resistant or opportunistic organisms
• B. Permanent increase in normal bowel bacteria
• C. Improved response to every future antibiotic
• D. Prevention of all drug-related allergic reactions

Explanation: Broad-spectrum therapy affects many bacterial species, including protective normal flora, and may promote antimicrobial resistance or…

• A. Withhold the dose and notify the prescriber
• B. Give the next dose with an antacid
• C. Encourage extra potassium-rich foods
• D. Reassure the patient that this is harmless

Explanation: Gentamicin can cause ototoxicity, which may be irreversible, as well as nephrotoxicity.

• A. Report numbness or tingling in the hands and feet
• B. Stop treatment when the cough improves
• C. Take extra doses if one dose is missed
• D. Avoid all foods containing carbohydrates

Explanation: Isoniazid may cause peripheral neuropathy, especially in patients at risk of pyridoxine deficiency, so numbness or tingling should be…

• A. Explain that this is an expected harmless effect
• B. Tell the patient to stop rifampicin immediately
• C. Administer vitamin K before the next dose
• D. Explain that it confirms kidney failure

Explanation: Rifampicin commonly discolors urine, sweat, saliva and tears orange-red.

• A. Nephrotoxicity from the antifungal drug
• B. Ototoxicity from the antifungal drug
• C. Retinal toxicity from the antifungal drug
• D. Severe hypoglycemia from the antifungal drug

Explanation: Amphotericin B can cause significant renal impairment and electrolyte disturbances, so renal function and electrolytes require monitoring.

• A. Maintain adequate fluid intake unless restricted
• B. Avoid all fluids until the treatment is complete
• C. Take double doses when lesions remain painful
• D. Use the drug only after eating fatty foods

Explanation: Adequate hydration helps reduce the risk of acyclovir crystalluria and renal injury, particularly when the patient is receiving high doses…

• A. Avoid alcohol during treatment and shortly after it ends
• B. Take the medicine only when fever becomes severe
• C. Stop the drug when diarrhoea improves
• D. Increase alcohol intake to improve absorption

Explanation: Alcohol taken with metronidazole may produce a disulfiram-like reaction with nausea, vomiting, flushing and abdominal discomfort.

• A. Collect the urine specimen using the prescribed technique
• B. Delay all treatment until the culture result returns
• C. Give an antidiarrhoeal medicine before collecting urine
• D. Discard the first urine and collect no further specimen

Explanation: When the patient is stable, the culture specimen should be collected before antibiotics because treatment can reduce bacterial growth and…

• A. Explain that antibiotics do not treat dengue viruses
• B. Give an antibiotic to prevent every possible infection
• C. Explain that antibiotics destroy dengue virus directly
• D. Withhold all fluids until the fever returns to normal

Explanation: Dengue is a viral infection, so antibiotics do not treat its cause; management includes monitoring, fluids as prescribed and safe fever…

• A. It kills bacteria by destroying their cell walls
• B. It stops bacterial growth and allows host defenses to clear them
• C. It prevents all bacterial toxins from entering the bloodstream
• D. It kills bacteria by immediately blocking nerve transmission

Explanation: A bacteriostatic drug inhibits bacterial growth or reproduction rather than directly killing the organisms.

• A. Continue the broad-spectrum drug indefinitely
• B. Change to the effective narrow-spectrum drug as prescribed
• C. Add a second antibiotic without consulting the prescriber
• D. Stop antimicrobial treatment because the culture is complete

Explanation: Using the narrowest effective antibiotic reduces exposure to other bacteria and lowers the risk of resistance and superinfection.

• A. Offer oral fluids and reassess in 30 minutes
• B. Stop the drug and call for emergency treatment
• C. Document the reaction after completing the medication round
• D. Give the next dose slowly to reduce further symptoms

Explanation: Wheezing and facial swelling indicate a potentially life-threatening anaphylactic reaction, so the drug must be stopped and emergency help…

• A. I will take it with an antacid to prevent stomach upset
• B. I will use sun protection while taking this medicine
• C. I will stop it when my fever returns to normal
• D. I will take each dose with milk to improve absorption

Explanation: Doxycycline can cause photosensitivity, so protective clothing and sunscreen are appropriate during treatment.

• A. Increase the infusion rate to complete the dose quickly
• B. Stop or slow the infusion and notify the prescriber
• C. Give the next dose by the intramuscular route
• D. Tell the patient that the reaction proves treatment failure

Explanation: Rapid intravenous vancomycin infusion can cause an infusion reaction with flushing and itching, often called vancomycin infusion reaction.

• A. Swallow it immediately without holding it in the mouth
• B. Swish it around the mouth before swallowing it
• C. Dilute it in a full glass of water before taking it
• D. Apply it only to the skin around the lips

Explanation: Nystatin suspension should contact the affected oral mucosa, so the patient should swish it around the mouth before swallowing.

• A. That plan prevents all adverse effects from the medicines
• B. These medicines work best when taken consistently as prescribed
• C. Missing doses is safe if the viral load was once low
• D. The medicines can be stopped after symptoms improve

Explanation: Consistent adherence suppresses viral replication and reduces the risk of treatment failure and drug resistance.

• A. Whether the patient has a history of motion sickness
• B. Whether the patient has glucose-6-phosphate dehydrogenase deficiency
• C. Whether the patient received a tetanus booster this year
• D. Whether the patient has previously used an antifungal cream

Explanation: Primaquine can cause severe haemolysis in patients with glucose-6-phosphate dehydrogenase deficiency, so screening or confirmation of G6PD…

• A. Use the remaining tablets whenever a fever develops
• B. Complete the prescribed course and do not share or save doses
• C. Take double doses later if some tablets are missed
• D. Keep the tablets for a family member with similar symptoms

Explanation: The patient should take the antibiotic exactly as prescribed and follow local guidance for safe disposal of unused medicine.

• A. It blocks bacterial folic acid synthesis
• B. It disrupts fungal ergosterol production
• C. It prevents viral protein attachment
• D. It inhibits parasite muscle contraction

Explanation: Trimethoprim inhibits bacterial dihydrofolate reductase, reducing folic acid needed for nucleic acid production.