Acute upper urinary tract infection (pyelonephritis/urosepsis) (Antimicrobial)
TAM (Treatments and Medicines) NHS Highland
Upper urinary-tract infection (pyelonephritis) in men, women
- CKS
- NHS Highland guideline UTI Management in Pregnancy (NHS Highland intranet access required).
Send urine sample to bacteriology before treatment commences. If no response in 24 hours consider hospital admission.
NOTE: Avoid co-amoxiclav due to increased resistance in Gram negative pathogens associated with urinary tract infection
NOTE: Avoid ciprofloxacin due to MHRA restrictions (updated January 2024) on the use of fluoroquinolone antibiotics following a review of disabling and potentially long-lasting side effects mainly involving muscles, tendons, bones and the nervous system. Whilst these antibiotics are likely to be effective in upper urinary tract infection, they should be avoided unless ALL OTHER ORAL ANTIBIOTICS ARE UNSUITABLE.
Co-trimoxazole should be used with caution in severe renal impairment (eGFR less than 30mL/min). Use with caution with drugs that promote hyperkalaemia and monitor serum potassium levels if used for longer than 3 days.
Due to competition for renal secretion, serum creatinine may rise in any patient without change in glomerular filtration rate – use with caution in renal transplant patients as the rise can be difficult to interpret.
For management of kidney transplant patients, immunocompromised patients and known or suspected infections with multi-drug resistant pathogens including ESBLs, contact Microbiology for discussion of treatment options.
Discuss antimicrobial cover for urinary catheter exchange in a patient with a recent joint replacement with Microbiology.
For glossary of terms see Glossary.
Drug details
For moderate illness with systemic upset not requiring hospital admission.
Cefalexin 1 gram, 3 times daily
7 days
In beta-lactam allergy (beware of side effect risk, see notes above)
Co-trimoxazole 960mg, twice daily. When sensitivities are known, suitable oral agents include amoxicillin and trimethoprim, in addition to those recommended above.
7 days
For severe infection (hospital treated)
Mandatory review of gentamicin following culture and sensitivity information.
Check SCi Store for urinary pathogens isolated in last 6 months not covered by gentamicin or aztreonam and seek advice from Microbiology.
Gentamicin (intravenous) - refer to NHS Highland gentamicin dosing guidelines.
7 to 14 days
In severe renal impairment (CrCl less than 10ml/min) or renal replacement therapy or where gentamicin unsuitable. Review dose if renal function improves.
Aztreonam (intravenous) 1 gram stat then 250mg every 8 hours.
7 to 14 days
When switching to oral therapy without positive microbiology results
Follow recommendations for moderate illness.
For infections arising within 24 hours of surgery where gentamicin has been given as part of surgical prophylaxis
Substitute intravenous aztreonam 1 gram every 8 hours for gentamicin.