Adult

Pseudomonas aeruginosa- MDR treatment (DTR-PSAR)

Treatment of difficult-to-treat resistant Pseudomonas aeruginosa (DTR-PSAR) infection

Always discuss with Micro/ ID - not all cases need treatment.

Enhanced infection control precautions are needed. Inform IPC team.

DTR-PSAR is defined as P. aeruginosa exhibiting non-susceptibility to all of the following: piperacillin-tazobactam, ceftazidime, cefepime, aztreonam, meropenem, imipenem-cilastatin, ciprofloxacin, and levofloxacin

  • PSAR Colonisation without active infection is NOT an indication for treatment
  • NB when treating true infections due to DTR-PSAR, higher dosing regimens may be appropriate - follow Micro/ID advice
  • The antibiotics described are RESTRICTED and their use must be discussed with Micro/ID

Preferred - empirical, when first line agents are resistant

Respiratory indications: Ceftolozane with tazobactam 3g iv tds

Other indications: Ceftolozane with tazobactam 1.5g iv tds

Alternative - depending on susceptibility tests

Ceftazidime with avibactam (Zavicefta®) 2.5g every iv tds

OR, Recarbrio® (Imipenem-cilastatin-relebactam) 1.25g iv qds

UTI can be treated with once daily aminoglycosides:

eg gentamicin 5mg/kg iv (Gentamicin is for a maximum of 3 days). Take a gentamicin level at 6-14 hours after first dose to calculate dosing interval, usually 24 hourly, 36 hourly or 48 hourly. See gentamicin monograph for dosing (including renal dosing) and monitoring.

OR

amikacin 15mg/kg iv od (max dose:1.5g iv od). Daily U&Es recommended. See amikacin mongraph for dosing and monitoring.

 

Other regimens and combination therapy may be recommended by Micro/ID, including:

  • cefiderocol 2g iv tds
  • colistimethate sodium Loading dose of 9 Million International Units (MIU) iv followed by maintenance dose 3 Million International Units (MIU) iv tds (see cautions below)
  • fosfomycin 4-8g iv tds

When prescribing colistimethate sodium:-

  • Ensure daily monitoring of renal function and consult with Micro/ID BEFORE starting
  • Review other nephrotoxic medications
  • Contraindicated in patients with myasthenia gravis

Further Advice

Always discuss treatment with Micro/ID.

Infection control team can be contacted via:

Monday-Friday 8:30am - 5pm: Bleep 1747 

Saturday 9am to 5pm: Bleep 1747 

For IPC advice across all sites after 5pm or on a Sunday: contact the on-call microbiologist via switchboard

Editorial Information

Last reviewed: 01 May 2025