Benefits noted for ceftolozane-tazobactam for treating MDR Pseudomonas

Ceftolozane-tazobactam for patients with multidrug-resistant (MDR) Pseudomonas aeruginosaillness, known for being a hard-to-treat hospital-acquired infection, is effective, especially when used early, researchers who studied use of the therapy in a multicenter study reported today in Open Forum Infectious Diseases.

For their retrospective study, the investigators collected information on US adults from 20 hospitals who received ceftolozane-tazobactam treatment for MDR Pseudomonas infections from any source for at least 24 hours. Of 205 patients included in the analysis, severe illness and high levels of other medical conditions were common—59% had pneumonia. The team found that delayed treatment was common, with therapy beginning at a median of 9 days after culture collection.

Susceptibility testing found that 125 of 139 (89.9%) of isolates were susceptible to the drug combination. Deaths occurred in 39 (19%) of patients, with clinical success and microbiological cure numbers at 151 (73.7%) and 145 (70.7%), respectively.

Being started on ceftolozane-tazobactam treatment within 4 days of culture collection was associated with survival, clinical success, and microbiological cure.

The researchers said their study is the largest they know of so far to evaluate the treatment combo for MDR Pseudomonas infections. They highlighted the fact that no positive results were seen for concomitant intravenous antibiotics or high-dose ceftolozane-tazobactam treatment, though both practices were common, hinting that monotherapy may be enough for treating susceptible Pseudomonas infections.

They also said the benefit of earlier treatment initiation was significant. “Antimicrobial stewardship programs and individual practitioners alike need to strike a difficult balance between early use of agents such as ceftolozane-tazobactam in appropriate patients who may benefit from it with the economic and microbiological consequences of overuse,” they wrote, acknowledging that rapid tests and scoring systems for MDR may help flag patients who could benefit from earlier treatment.

Source: CIDRAP