Clinical characteristics and prognosis of infections caused by OXA-48 carbapenemase-producing Enterobacteriaceae in patients treated with ceftazidime-avibactam.

Background: Ceftazidime-avibactam has in vitro activity against Gram-negative bacilli that produce Class A, C and some D β-lactamases, and has been successfully used in the treatment of infections caused by cephalosporin and carbapenem-resistant Enterobacteriaceae. However, actual experience in the treatment of OXA-48 carbapenemase-producing Enterobacteriaceae (CPE) is limited.

Objective: To review the characteristics and prognosis of OXA-48 CPE infections treated with ceftazidime-avibactam since introduction of the drug to the current centre during the period October 2014 to December 2016.

Methods: Retrospective assessment of episodes of infection caused by OXA-48 CPE treated with ceftazidime-avibactam, analysing data collected from infection diagnosis until 90 days after the end of treatment.

Results: Twenty-four episodes were analysed. Ceftazidime-avibactam was given as the initial definitive treatment in 15 (62.5%) and as salvage therapy in nine (37.5%). Intraabdominal (seven, 29%), urinary (six, 25%) and respiratory (five, 21%) were the most common sources. The 30-day and 90-day mortality rates were 8.3% and 20.8%, respectively. Clinical cure at 30 days was achieved in 62.5% of episodes. Four (16.7%) patients had adverse events, two of them were related to impaired renal function. Among patients who finished the treatment with ceftazidime-avibactam, seven (35%) were diagnosed with infection recurrence within 90 days of the end of treatment.

Conclusions: From experience, ceftazidime-avibactam is an effective drug for treating infections due to OXA-48 CPE. From these results a better safety profile than the current best available therapy could be expected.