Canterbury DHB


June 2023

Antimicrobial Guidelines

Acute Pyelonephritis or Complicated Urinary Tract Infection


  • Our recommended cefalexin dose for this indication is 1000 mg four times daily except in renal failure. As other reference sources suggest an inappropriately low dose for gram-negative infections outside of the bladder, we have added a statement “Local experts recommend a high dose is used based on local studies to ensure adequate concentrations against E. coli in the blood stream and kidney as well as bladder” for clarity.
  • Ciprofloxacin oral dose for directed therapy against Pseudomonas aeruginosa is now 750 mg twice daily.
  • Trimethoprim is no longer in this guideline. For directed therapy against E. coli, our first choice is high dose cefalexin and our second choice is trimethoprim+sulfamethoxazole.

Surgical Post-operative Antimicrobial Guidelines


  • The text “post-operative” is now added after each individual post-operative guideline name to help those who use the search function identify the correct guideline. A search for “pneumonia” will now identify four guidelines i.e. “hospital-acquired pneumonia, “community-acquired pneumonia” and “aspiration pneumonia”, as well as “pneumonia (post-operative)”.

Urinary Tract Infection / Pyelonephritis (Post-operative)


  • Our empiric antimicrobial guideline for post-operative urosepsis and the Urology urosepsis protocol now align. The changes aim to improve safety of gentamicin (concentration monitoring, and no more than 72 hours without infectious diseases advice) and efficacy of amoxicillin (increased dose). Variations for penicillin allergy, renal impairment and prior ESBL infection have also been added.

Post-TRUS sepsis


  • Piperacillin+tazobactam is now dosed every 6 hours for sepsis.

Information about this Canterbury DHB document (1176071):

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Last Updated:

June 2023

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Topic Code: 1176071