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Acute pyelonephritis — MSRA MCQ

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HardUrinary Tract InfectionsAcute pyelonephritisMSRA

A 46-year-old non-pregnant woman presents with 24 hours of dysuria and urinary frequency followed by rigors, a temperature of 38.4°C and right-sided loin pain. She is alert, drinking adequately and has not vomited. Her heart rate is 96 beats/minute, blood pressure 124/76 mmHg and respiratory rate 16 breaths/minute. She has right costovertebral-angle tenderness but no features of sepsis. A midstream urine sample is obtained before treatment. Her eGFR is 74 mL/minute/1.73 m². A culture-confirmed Escherichia coli UTI 4 months ago was resistant to cefalexin, co-amoxiclav and trimethoprim, but susceptible to ciprofloxacin. She has not received antibiotics since. She has no history of fluoroquinolone adverse effects, tendon disorder, aortic aneurysm or systemic corticosteroid use. What is the most appropriate immediate management?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Start ciprofloxacin 500 mg twice daily for 7 days, provide fluoroquinolone safety-netting, and review the urine culture result.

Explanation lettering: B = shown as A · C = shown as B · E = shown as C · A = shown as E

This is acute pyelonephritis, rather than uncomplicated lower UTI, because fever, rigors and costovertebral-angle tenderness indicate upper urinary tract involvement. She can take oral medication, is not vomiting and has no sepsis or haemodynamic instability, so immediate intravenous treatment or hospital referral is not required solely on the information given. Ciprofloxacin is appropriate because NICE advises oral ciprofloxacin 500 mg twice daily for 7 days when other commonly recommended antibiotics are unsuitable. Her recent culture makes cefalexin, co-amoxiclav and trimethoprim poor empirical choices; ciprofloxacin was susceptible. Its use must be accompanied by counselling about potentially disabling and prolonged adverse effects, with advice to stop and seek review if these develop. A is inappropriate because nitrofurantoin does not achieve adequate renal-tissue concentrations for pyelonephritis. B is initially attractive because cefalexin is usually a first-choice oral option, but her recent isolate was resistant. D would be appropriate if she were unable to take oral treatment, vomiting, severely unwell or septic. E is unsafe: acute pyelonephritis requires prompt antibiotic treatment after obtaining urine for culture.

Reference: NICE NG111: Pyelonephritis (acute): antimicrobial prescribing — Recommendations (Updated September 2024) — https://www.nice.org.uk/guidance/NG111/chapter/recommendations NICE NG111: Pyelonephritis (acute): antimicrobial prescribing — Summary of the evidence (2018) — https://www.nice.org.uk/guidance/NG111/chapter/summary-of-the-evidence MHRA Drug Safety Update: Fluoroquinolone antibiotics must now only be prescribed when other commonly recommended antibiotics are inappropriate (22 January 2024) — https://www.gov.uk/drug-safety-update/fluoroquinolone-antibiotics-must-now-only-be-prescribed-when-other-commonly-recommended-antibiotics-are-inappropriate