NICE NG109 2018: lower UTI antimicrobial prescribing guidelines

Who it applies to

Applies to adults, pregnant women, and children/young people with suspected or confirmed lower UTI (cystitis) managed in primary and community care.

Key recommendations

• For non-pregnant women with suspected UTI, consider a midstream urine culture only if risk factors for resistance or complication are present, atypical symptoms, or treatment failure; otherwise diagnose clinically.
• First-line empirical antibiotics for uncomplicated lower UTI in non-pregnant women are nitrofurantoin or trimethoprim, chosen with regard to local resistance data, depending on renal function for nitrofurantoin.
• A 3-day course is recommended for non-pregnant women with uncomplicated lower UTI.
• Men with lower UTI symptoms should be treated with a 7-day course of antibiotics, reflecting the possibility of occult prostatic involvement.
• Pregnant women with symptomatic lower UTI should have a urine culture sent before starting antibiotics, with nitrofurantoin generally first line (avoided near term) and amoxicillin or cefalexin as alternatives depending on sensitivities.
• Trimethoprim should be avoided in the first trimester of pregnancy due to teratogenic risk, and nitrofurantoin should be avoided at term due to risk of neonatal haemolysis.
• For children and young people aged 3 months and older with suspected UTI, a urine sample should be sent for culture before starting antibiotics, and a 3-day course of either trimethoprim or nitrofurantoin is recommended as first-choice empirical treatment; specialist advice is reserved for infants under 3 months.
• Second-choice agents (e.g., pivmecillinam, fosfomycin, or an alternative first-line agent) should be considered if there is no improvement on first-choice therapy after 48 hours or if first-choice agents are unsuitable.
• Safety-netting advice should be given to all patients, including when to seek further medical review if symptoms worsen or do not improve.

Practice points for students

• Nitrofurantoin should generally be avoided if eGFR is below 45 mL/min/1.73m2, though it may still be used cautiously in some circumstances with lower eGFR for short courses.
• Men are treated for 7 days, not 3 days, because of the risk of occult prostatic involvement.
• Trimethoprim carries teratogenicity risk in early pregnancy due to folate antagonism, so alternatives are preferred in the first trimester.
• In children aged 3 months and older, a 3-day course of trimethoprim or nitrofurantoin is first-line, while infants under 3 months need specialist advice.

Condition

Other guidelines on this topic

• Clinical Practice Guidelines by Infectious Diseases Society of America (IDSA): 2025 Guidelines on Management and Treatment of Complicated Urinary Tract Infections--Duration of Antibiotics for Complicated UTIIDSA2026Official guideline
• The 2025 AUA Guideline Update on Recurrent Urinary Tract Infections: Important New Recommendations Reflecting Progress in an Often-Ignored Disease SpaceAUA2026Official guideline

Independent educational summary written by the WhiteCoat Pro editorial team with AI assistance and checked by a second AI model. It does not reproduce the guideline text, tables or figures, and it is not affiliated with or endorsed by NICE. It is not medical advice: always read the original guideline before applying it to patients.