A patient with ventilator-associated pneumonia is on piperacillin-tazobactam, vancomycin and amikacin. Cultures grow a susceptible Pseudomonas aeruginosa only, and a nasal MRSA PCR is negative. Which action reflects good stewardship?

Stop vancomycin and narrow to one active anti-pseudomonal agent

Stop piperacillin-tazobactam and keep vancomycin and amikacin until day 14

Continue all three drugs until day 14

In standard first-line treatment of drug-susceptible pulmonary tuberculosis, what does the 2-month intensive phase contain?

Isoniazid, rifampicin, pyrazinamide and ethambutol

Isoniazid, rifampicin and levofloxacin

After bismuth quadruple therapy fails in a 52-year-old man, which regimen is a reasonable next empirical treatment?

PPI, amoxicillin and levofloxacin for 14 days

PPI and metronidazole for 14 days

PPI, amoxicillin and clarithromycin for 14 days

A repeat 14-day course of bismuth quadruple therapy

A hospital in Dubai reports clarithromycin resistance of about 25% among its H. pylori isolates. A 38-year-old woman with no prior macrolide use needs first-line therapy. Which choice is most appropriate?

Bismuth quadruple therapy for 14 days

PPI and clarithromycin only for 14 days

PPI, amoxicillin and clarithromycin for 14 days

PPI, amoxicillin and rifabutin for 14 days

Antimicrobial selection and stewardship

46 Gulf Prometric Pharmacist (DHA, DOH, MOH, SCFHS, QCHP) practice questions on Antimicrobial selection and stewardship, part of Clinical Pharmacy and Therapeutics. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 70-year-old man weighing 60 kg with serum creatinine 180 umol/L has pneumonia and is prescribed levofloxacin. Using Cockcroft-Gault, which regimen is appropriate?
1. A250 mg every 48 hours
2. B500 mg every 12 hours
3. C750 mg every 24 hours
4. D750 mg every 48 hours
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Answer: D · 750 mg every 48 hours
CrCl = (140 - 70) x 60 x 1.23 / 180 = about 29 mL/min. For a CrCl of 20-49 mL/min, the 750 mg regimen is given every 48 hours, whereas 750 mg daily is the normal-function dose.
- A: 250 mg every 48 hours is not a labelled regimen.
- B: 500 mg every 12 hours is not a labelled regimen.
- C: 750 mg every 24 hours is the normal-function dose.
Remember this
Adjust levofloxacin for renal function using Cockcroft-Gault.
Question 2 · Medium
A patient with ventilator-associated pneumonia is on piperacillin-tazobactam, vancomycin and amikacin. Cultures grow a susceptible Pseudomonas aeruginosa only, and a nasal MRSA PCR is negative. Which action reflects good stewardship?
1. AStop vancomycin and narrow to one active anti-pseudomonal agent
2. BStop piperacillin-tazobactam and keep vancomycin and amikacin until day 14
3. CAdd meropenem for extra cover
4. DContinue all three drugs until day 14
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Answer: A · Stop vancomycin and narrow to one active anti-pseudomonal agent
A negative nasal MRSA PCR has a negative predictive value above 95% for MRSA pneumonia, so vancomycin can stop. With a susceptible Pseudomonas isolate, a single active beta-lactam is enough, and amikacin can also be dropped. This lowers nephrotoxicity and resistance pressure.
- B: Vancomycin has no target organism, so it should be the first to stop.
- C: Meropenem broadens, not narrows, therapy.
- D: Three drugs for 14 days is needless exposure.
Remember this
Negative MRSA nasal PCR plus Pseudomonas culture allows stopping vancomycin and narrowing.
Question 3 · Easy
In standard first-line treatment of drug-susceptible pulmonary tuberculosis, what does the 2-month intensive phase contain?
1. AIsoniazid, rifampicin and levofloxacin
2. BRifampicin and streptomycin
3. CIsoniazid, rifampicin, pyrazinamide and ethambutol
4. DIsoniazid and rifampicin only
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Answer: C · Isoniazid, rifampicin, pyrazinamide and ethambutol
The standard regimen is 2 months of isoniazid, rifampicin, pyrazinamide and ethambutol (HRZE), followed by 4 months of isoniazid and rifampicin (HR). Four drugs in the intensive phase reduce the risk of resistance.
- A: Fluoroquinolones are used for drug-resistant disease.
- B: Streptomycin is a second-line injectable alternative.
- D: Two drugs are used in the continuation phase, not the intensive phase.
Remember this
Standard TB treatment: 2 months of HRZE, then 4 months of HR.
Question 4 · Medium
After bismuth quadruple therapy fails in a 52-year-old man, which regimen is a reasonable next empirical treatment?
1. APPI and metronidazole for 14 days
2. BPPI, amoxicillin and clarithromycin for 14 days
3. CPPI, amoxicillin and levofloxacin for 14 days
4. DA repeat 14-day course of bismuth quadruple therapy
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Answer: C · PPI, amoxicillin and levofloxacin for 14 days
After a failed bismuth quadruple regimen, a levofloxacin-containing triple regimen (or a rifabutin triple regimen) is recommended, ideally guided by susceptibility testing. Levofloxacin and amoxicillin use mechanisms the patient has not yet been exposed to. Repeating the same regimen risks repeated failure and added toxicity.
- A: A PPI with metronidazole alone is not an eradication regimen.
- B: Clarithromycin triple therapy is usually poor in a patient already failing treatment in a high-resistance setting.
- D: Repeating a failed regimen is not advised.
Remember this
After failed bismuth quadruple therapy, use a levofloxacin or rifabutin triple regimen.
Question 5 · Medium
A hospital in Dubai reports clarithromycin resistance of about 25% among its H. pylori isolates. A 38-year-old woman with no prior macrolide use needs first-line therapy. Which choice is most appropriate?
1. ABismuth quadruple therapy for 14 days
2. BPPI and clarithromycin only for 14 days
3. CPPI, amoxicillin and clarithromycin for 14 days
4. DPPI, amoxicillin and rifabutin for 14 days
Show answerHide answer
Answer: A · Bismuth quadruple therapy for 14 days
When local clarithromycin resistance is above 15%, clarithromycin-containing triple therapy should be avoided empirically because resistance sharply lowers cure rates. Bismuth quadruple therapy remains effective as metronidazole resistance can be overcome by the 14-day course and tetracycline resistance is rare. Rifabutin regimens are kept for rescue to protect that drug for tuberculosis.
- B: Dual therapy with clarithromycin alone fails at this resistance level.
- C: Adding amoxicillin does not rescue the clarithromycin-resistant fraction.
- D: Rifabutin is reserved for refractory infection and adds toxicity.
Remember this
Avoid empirical clarithromycin triple therapy where resistance exceeds 15%.
Question 6 · Medium
Five weeks into treatment with isoniazid, rifampicin, pyrazinamide and ethambutol, a patient becomes jaundiced and nauseated, and the ALT is 6 times the upper limit of normal. What is the most appropriate action?
1. AStop all hepatotoxic anti-TB drugs and reintroduce them sequentially after recovery
2. BContinue all four drugs, add a hepatoprotective supplement, and recheck the ALT in 3 months
3. CHalve the dose of every drug and continue
4. DStop only ethambutol and continue the other three
Answer and explanation in LearnFree account
Question 7 · Medium
A patient with C. difficile infection becomes hypotensive and distended with absent bowel sounds. Which regimen is recommended for fulminant disease?
1. AOral vancomycin 500 mg four times daily plus intravenous metronidazole 500 mg every 8 hours
2. BOral vancomycin 125 mg four times daily alone
3. COral metronidazole 500 mg three times daily alone, continued for the standard 10 to 14 days of therapy
4. DOral fidaxomicin 200 mg twice daily alone
Answer and explanation in LearnFree account
Question 8 · Medium
A 45-year-old man finished 14 days of H. pylori treatment and takes omeprazole daily for reflux. The clinic plans a urea breath test to confirm eradication. What is the correct preparation?
1. AKeep the PPI going; test 2 weeks after finishing antibiotics
2. BStop the PPI 2 weeks before; test 1 week after finishing antibiotics
3. CStop the PPI 2 weeks before; test 4 or more weeks after antibiotics
4. DStop the PPI 48 hours before; test 4 or more weeks after antibiotics
Answer and explanation in LearnFree account
Question 9 · Medium
In an area of high clarithromycin resistance, which regimen is recommended first-line for Helicobacter pylori eradication?
1. AAmoxicillin alone for 14 days
2. BBismuth quadruple therapy for 14 days
3. CPPI alone for 8 weeks
4. DPPI, amoxicillin and clarithromycin for 7 days
Answer and explanation in LearnFree account
Question 10 · Medium
A patient with MSSA bacteraemia, started on vancomycin and piperacillin-tazobactam, has culture results at 48 hours. What is the best antimicrobial stewardship action?
1. AContinue both drugs for 14 days
2. BDe-escalate to cefazolin or flucloxacillin
3. CAdd meropenem
4. DSwitch to linezolid
Answer and explanation in LearnFree account
Question 11 · Easy
What is the first management step for a hospitalised patient who develops C. difficile infection while receiving a broad-spectrum antibiotic?
1. AStop the inciting antibiotic as soon as it is safe to do so
2. BStop all oral intake for 10 days
3. CAdd a second broad-spectrum antibiotic
4. DContinue it unchanged and add loperamide to control the diarrhoea
Answer and explanation in LearnFree account
Question 12 · Medium
Which finding best supports switching a hospitalised patient with pneumonia from intravenous to oral antibiotics?
1. APersistent fever with rising CRP and a rising white cell count over 48 hours
2. BInability to swallow and ongoing vomiting
3. CPositive blood cultures not yet speciated
4. DAfebrile, haemodynamically stable, improving and tolerating oral intake
Answer and explanation in LearnFree account
Question 13 · Hard
A 34-year-old man with HIV, controlled on dolutegravir 50 mg once daily, is diagnosed with drug-susceptible TB and starts rifampicin-based therapy. How should the antiretroviral be adjusted?
1. AIncrease dolutegravir to 50 mg twice daily during rifampicin
2. BContinue dolutegravir 50 mg once daily without change
3. CReduce dolutegravir to 25 mg once daily to limit the risk of toxicity
4. DReplace dolutegravir with lopinavir/ritonavir
Answer and explanation in LearnFree account
Question 14 · Medium
A pharmacist counsels a patient starting PPI, bismuth subsalicylate, tetracycline and metronidazole for H. pylori. Which advice is most important for safety?
1. AExpect pale stools while taking bismuth
2. BStop the regimen on day 7 if symptoms improve
3. CAvoid alcohol during and for 72 hours after metronidazole
4. DTake tetracycline together with calcium antacids for comfort
Answer and explanation in LearnFree account
Question 15 · Medium
Which infection-control measure is most appropriate when caring for a ward patient with C. difficile infection?
1. AStandard precautions with no contact isolation
2. BSoap-and-water hand washing, gloves and gowns, and a single room
3. CDroplet precautions with a surgical mask
4. DAlcohol hand gel alone, with standard precautions and no isolation room
Answer and explanation in LearnFree account
Question 16 · Hard
A patient with documented anaphylaxis to penicillin needs Helicobacter pylori eradication. Which regimen is most appropriate?
1. APPI and rifabutin with amoxicillin
2. BPPI, amoxicillin and metronidazole
3. CPPI, amoxicillin and clarithromycin
4. DPPI, bismuth, tetracycline and metronidazole
Answer and explanation in LearnFree account
Question 17 · Easy
A healthcare worker with latent tuberculosis infection (no active disease) wants a short treatment. Which regimen is recommended?
1. AEthambutol daily for 6 months
2. BIsoniazid once weekly for 4 weeks
3. CPyrazinamide daily for 2 months
4. DRifampicin daily for 4 months
Answer and explanation in LearnFree account
Question 18 · Medium
Which first-line antituberculosis drug requires baseline and periodic checks of visual acuity and colour vision?
1. AStreptomycin
2. BEthambutol
3. CRifampicin
4. DPyrazinamide
Answer and explanation in LearnFree account
Question 19 · Medium
A patient needs a urea breath test to confirm Helicobacter pylori eradication. How should the proton pump inhibitor be handled beforehand?
1. AStop it 24 hours before the test
2. BContinue it and double the dose
3. CStop it at least 2 weeks before the test
4. DStop it 3 days before the test
Answer and explanation in LearnFree account
Question 20 · Medium
A patient treated with a 10-day course of oral vancomycin has a first recurrence of C. difficile infection 3 weeks later. Which treatment is preferred?
1. AIntravenous vancomycin
2. BA repeat 10-day course of standard-dose metronidazole
3. CFidaxomicin, standard or extended-pulsed regimen
4. DNo treatment, as recurrence is usually self-limiting
Answer and explanation in LearnFree account
Question 21 · Medium
Procalcitonin is being used to guide antibiotic duration in a patient with community-acquired pneumonia. Which result supports stopping antibiotics?
1. AProcalcitonin of 10 microgram/L on day 3 with no change from the baseline value
2. BProcalcitonin doubling after 48 hours
3. CProcalcitonin falling by 80% or more from its peak, or below 0.5 microgram/L
4. DAny detectable procalcitonin on day 5
Answer and explanation in LearnFree account
Question 22 · Hard
A patient in intensive care has bacteraemia with Klebsiella pneumoniae that produces NDM-1 (a metallo-beta-lactamase) and an ESBL. Which regimen is the most reliable choice?
1. AHigh-dose meropenem given as an extended infusion
2. BMeropenem-vaborbactam given as an extended infusion
3. CCeftazidime-avibactam given alone at the full dose
4. DCeftazidime-avibactam given together with aztreonam
Answer and explanation in LearnFree account
Question 23 · Medium
A woman with Staphylococcus aureus bacteraemia is on cefazolin. Which step is recommended in every adult with this infection?
1. AStopping antibiotics once she is afebrile
2. BEchocardiography and repeat blood cultures
3. CSwitching to oral therapy on day 3
4. DAdding rifampicin for synergy
Answer and explanation in LearnFree account
Question 24 · Medium
A patient with a creatinine clearance of 35 mL/min needs fluconazole for oesophageal candidiasis. The usual dose is 200 mg daily. What is the best adjustment?
1. AAvoid fluconazole altogether
2. BContinue 200 mg daily unchanged
3. CGive 200 mg every 72 hours
4. DGive 100 mg daily after the loading dose
Answer and explanation in LearnFree account
Question 25 · Medium
A 62-year-old patient has suspected bacterial meningitis. Which empirical regimen is appropriate?
1. ACiprofloxacin and gentamicin, with dexamethasone
2. BCeftriaxone, vancomycin, ampicillin and dexamethasone
3. CCeftriaxone and metronidazole, with dexamethasone
4. DAzithromycin and metronidazole, with dexamethasone
Answer and explanation in LearnFree account

21 more Antimicrobial selection and stewardship questions

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Antimicrobial selection and stewardship

A 70-year-old man weighing 60 kg with serum creatinine 180 umol/L has pneumonia and is prescribed levofloxacin. Using Cockcroft-Gault, which regimen is appropriate?

A patient with ventilator-associated pneumonia is on piperacillin-tazobactam, vancomycin and amikacin. Cultures grow a susceptible Pseudomonas aeruginosa only, and a nasal MRSA PCR is negative. Which action reflects good stewardship?

In standard first-line treatment of drug-susceptible pulmonary tuberculosis, what does the 2-month intensive phase contain?

After bismuth quadruple therapy fails in a 52-year-old man, which regimen is a reasonable next empirical treatment?

A hospital in Dubai reports clarithromycin resistance of about 25% among its H. pylori isolates. A 38-year-old woman with no prior macrolide use needs first-line therapy. Which choice is most appropriate?

Five weeks into treatment with isoniazid, rifampicin, pyrazinamide and ethambutol, a patient becomes jaundiced and nauseated, and the ALT is 6 times the upper limit of normal. What is the most appropriate action?

A patient with C. difficile infection becomes hypotensive and distended with absent bowel sounds. Which regimen is recommended for fulminant disease?

A 45-year-old man finished 14 days of H. pylori treatment and takes omeprazole daily for reflux. The clinic plans a urea breath test to confirm eradication. What is the correct preparation?

In an area of high clarithromycin resistance, which regimen is recommended first-line for Helicobacter pylori eradication?

A patient with MSSA bacteraemia, started on vancomycin and piperacillin-tazobactam, has culture results at 48 hours. What is the best antimicrobial stewardship action?

What is the first management step for a hospitalised patient who develops C. difficile infection while receiving a broad-spectrum antibiotic?

Which finding best supports switching a hospitalised patient with pneumonia from intravenous to oral antibiotics?

A 34-year-old man with HIV, controlled on dolutegravir 50 mg once daily, is diagnosed with drug-susceptible TB and starts rifampicin-based therapy. How should the antiretroviral be adjusted?

A pharmacist counsels a patient starting PPI, bismuth subsalicylate, tetracycline and metronidazole for H. pylori. Which advice is most important for safety?

Which infection-control measure is most appropriate when caring for a ward patient with C. difficile infection?

A patient with documented anaphylaxis to penicillin needs Helicobacter pylori eradication. Which regimen is most appropriate?

A healthcare worker with latent tuberculosis infection (no active disease) wants a short treatment. Which regimen is recommended?

Which first-line antituberculosis drug requires baseline and periodic checks of visual acuity and colour vision?

A patient needs a urea breath test to confirm Helicobacter pylori eradication. How should the proton pump inhibitor be handled beforehand?

A patient treated with a 10-day course of oral vancomycin has a first recurrence of C. difficile infection 3 weeks later. Which treatment is preferred?

Procalcitonin is being used to guide antibiotic duration in a patient with community-acquired pneumonia. Which result supports stopping antibiotics?

A patient in intensive care has bacteraemia with Klebsiella pneumoniae that produces NDM-1 (a metallo-beta-lactamase) and an ESBL. Which regimen is the most reliable choice?

A woman with Staphylococcus aureus bacteraemia is on cefazolin. Which step is recommended in every adult with this infection?

A patient with a creatinine clearance of 35 mL/min needs fluconazole for oesophageal candidiasis. The usual dose is 200 mg daily. What is the best adjustment?

A 62-year-old patient has suspected bacterial meningitis. Which empirical regimen is appropriate?