Table 3.

Summary of recommendations in the ESCMID, IDSA and SEIMC guidelines for the treatment of infections due to multi-drug resistant/difficult to treat Pseudomonas aeruginosa. Dosages of the different antimicrobials are those included in the Summary of Product Characteristics (SmPC).

Infection type /combination therapy	ESCMID	IDSA	SEIMC
Low-risk, non-severe	Old antibiotics with in vitro activity	Ceftolozane-tazobactam or imipenem-relebactam or ceftazidime-avibactam or single dose aminoglycoside (uUTI)	Preferred: Ceftolozane-tazobactam Alternative: Ceftazidime-avibactam, or cefiderocol (uUTI)
Severe	Ceftolozane-tazobactam cefiderocol (cUTI)	Ceftolozane-tazobactam or imipenem-relebactam or ceftazidime-avibactam or cefiderocol (cUTI)	Preferred: Ceftolozane-tazobactam Alternative: Ceftazidime avibactam, imipenem-relebactam or colistin
Combination therapy	Not routinely recommended but if used, select two active antibiotics	Not routinely recommended but if preferred regimen has no in vitro activity combine with an aminoglycoside	Only in severe infections and those with high inoculum: - Ceftolozane-tazobactam or ceftazidime-avibactam with an active aminoglycoside or colistin - Fosfomycin (<128 mg/L) with an active compound - Avoid rifampicin, even in combination

uUTI: uncomplicated urinary tract infection; CUTI: complicated urinary tract infection