Pyelonephritis (fever, loin pain, systemically unwell) or any sepsis: assess for admission and IV antibiotics. Treat a UTI in pregnancy promptly and always send a culture.
Uncomplicated lower UTI (non-pregnant woman)
- Dysuria, frequency, urgency, suprapubic pain
- Nitrofurantoin first-line for 3 days (avoid if eGFR under 45)
- Alternative: trimethoprim (rising resistance) or pivmecillinam
- No routine dipstick or culture if the picture is clear
Special groups
- Pregnancy: treat (and treat asymptomatic bacteriuria); avoid trimethoprim in the first trimester, avoid nitrofurantoin at term; 7 days and send culture
- Men: treat 7 days, consider prostatitis
- Catheter: treat only if symptomatic, change the catheter
- Culture if recurrent, treatment failure, pregnant, male, catheter, or risk of resistance
Uncomplicated lower UTI
- Dysuria, frequency, no fever
- Nitrofurantoin 3 days (women)
- Check local sensitivities
Pyelonephritis
- Fever, flank pain, vomiting
- 7 to 10 days broad-spectrum
- Consider admission
Urosepsis
- Sepsis features, shock
- Sepsis Six within 1 h
- IV antibiotics, admit
Treatment
1
1. Confirm
Symptoms with or without dipstick support. Exclude an STI or vaginal cause if discharge or at risk. Send culture in the groups above.
Symptoms with or without dipstick support. Exclude an STI or vaginal cause if discharge or at risk. Send culture in the groups above.
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2
2. Choose antibiotic
Follow local resistance data and adjust for renal function and pregnancy. Shortest effective course (3 days uncomplicated woman).
Follow local resistance data and adjust for renal function and pregnancy. Shortest effective course (3 days uncomplicated woman).
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3
3. Safety-net
Review if fever, loin pain, vomiting, pregnancy, or no improvement after 48 h: consider pyelonephritis or resistance.
Review if fever, loin pain, vomiting, pregnancy, or no improvement after 48 h: consider pyelonephritis or resistance.
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4
4. Prevention (recurrent UTI)
Fluids and hygiene advice, vaginal oestrogen after the menopause, consider self-start or prophylaxis after specialist discussion.
Fluids and hygiene advice, vaginal oestrogen after the menopause, consider self-start or prophylaxis after specialist discussion.
Red flags for admission
- Signs of sepsis or shock
- Pregnancy with pyelonephritis
- Unable to tolerate oral fluids or antibiotics
- Suspected obstruction with infection (emergency)
Pitfalls
- Treating asymptomatic bacteriuria (except in pregnancy)
- Nitrofurantoin with low eGFR or at term
- Trimethoprim in the first trimester
- Missing pyelonephritis or urinary obstruction
MedPrep - www.medprep.uk - Educational revision aid only. Not clinical guidance. Doses are adult examples; check the BNF, current guidelines and local policy, and seek senior advice. Nov 2026