Antibiotic Guide for Urinary Tract Infections

For information on the diagnosis of UTI click here

Uncomplicated cystitis

• Send MSU/CSU

1st line therapy:

• Trimethoprim PO 200 mg  BD 3/7

2nd line therapy (non-response or resistant organism):

• Nitrofurantoin 50mg qds 3/7

Review antibiotics with culture results (see notes below)

Urosepsis/Pyelonephritis

• Send MSU/CSU and blood cultures

Before proceeding, please read advice regarding the national rise in multi-resistant Gram negative organisms  (here)

• Co-amoxiclav IV 1.2g TDS 

Or if mild rash with pencillins: Cefuroxime IV 1.5g tds (Not to be used in serious penicllin allergy, e.g. urticarial rash within the first 72 hours, anaphylaxis or angioedema.)

If patient has severe allergy to penicillins (e.g. urticarial rash within 72 hours, anaphylaxis or angioedema):

• Ciprofloxacin PO 500mg BD or if vomiting IV 400mg bd, after discussion with the duty medical microbiologist. As ciprofloxacin can increase selection for C.difficile infection and MRSA colonisation/infection, all patients with previous MRSA/C.difficile  require microbiology approval to use ciprofloxacin.

If the patient has severe sepsis or blood pressure fails to respond to initial fluid bolus, add the following to each of the above: Gentamicin IV 5mg/kg  (to a maximum 500mg) (reduce dose in renal impairment) infused over 20-30 minutes.

OR if risk of Multi resistant gram negatives

• Meropenem IV 1g tds (review antibiotics with microbiology within 48 hours). Not to be used in serious penicllin allergy e.g. urticarial rash within the first 72 hours, anaphylaxis or angioedema, please discuss with a Microbiologist.
• If the patient has severe sepsis or blood pressure fails to respond to initial fluid bolus: Gentamicin IV 5mg/kg  (to a maximum 500mg) (reduce dose in renal impairment) infused over 20-30 minutes.

OR if patient has severe allergy to penicillins (e.g. urticarial rash within 72 hours, anaphylaxis or angioedema):anaphylaxis to penicillins:

• Ciprofloxacin PO 500mg BD or if vomiting IV 400mg bd, after discussion with the duty medical microbiologist.
• Plus, if the patient has severe sepsis or blood pressure fails to respond to initial fluid bolus:  a single dose Gentamicin IV 5mg/kg  (to a maximum 500mg unless using dosing calculator) (reduce dose in renal impairment) infused over 20-30 minutes (Further doses should be according to the level 18-24 hours post 1st dose [normal trough level should be < 1mg/l])

Review antibiotics with culture results

Further therapy

Review need for antibiotics at 48 hours with microbiology results see IV-PO switch guideline

Total duration of IV and oral therapy 7-10 days

Notes

• For uncomplicated UTI in women, 3 days of oral therapy is normally sufficient. Complicated infections i.e pyelonephritis, underlying renal tract abnormalities, recent urinary surgery/instrumentation (excluding urinary tract catheterisation), UTI in diabetic and male patients may need therapy for 7-10 days.
• Trimethoprim and gentamicin (and nitrofurantoin) are usually active against MRSA - a cause of catheter-related UTI in hospital.
• Alternative agents to consider for organisms resistant to trimethoprim and  nitrofurantoin, include cefalexin and co-amoxiclav (depending on sensitivity results)

Page last edited: 16/10/2009

Caution; the antibiotic doses recommended on this website are intended for adult patients with normal renal and liver function unless otherwise stated. Dosing advice for patients with renal impairment is available here.

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