Ceftazidime-avibactam use in hematology patients: single-center experience

To investigate the efficacy of the cephalosporin/ beta lactamase inhibitor combination ceftazidime-avibactam in hematology patients with hematopoietic stem cell transplantation or receiving chemotherapy alone.

In this study, 80 patients who were followed up in the Stem Cell Transplant Center and Hematology Clinic of Istinye University Gaziosmanpaşa Medicalpark Hospital between June 2022 and May 2024 and who received ceftazidime-avibactam treatment for at least 3 days during their hospitalization were evaluated. Demographic characteristics, infectious processes, duration of hospitalization before culture, neutrophil levels and neutropenia duration at the time of treatment initiation, previous antibiotic exposure, Charlson's Comorbidity index, mechanical ventilation needs and mortality rates were recorded retrospectively.

Of the patients, 25 (31.25%) were female and 55 (68.75%) were male. The mean age was 50 years (18-86). Thirty-four (42.5%) patients received allogeneic hematopoietic stem cell transplantation and 17 (21.25%) patients received autologous hematopoietic stem cell transplantation. Only 29 (36.25%) patients received chemotherapy. When ceftazidime-avibactam treatment was initiated, 42 (52.5%) patients had a neutrophil count < 0.1 × 10⁹/L. Charlson's Comorbidity Index was ≥ 3 in 71 (88.75%) patients. Forty-six (57.5%) patients died in the first 28 days after the onset of infection. In multivariate analysis showed that mean age (HR 1.71, CI 1.07-3.05; p = 0.012), pneumonia and need for mechanical ventilation (HR 1.91, CI 1.83-1.98; p = 0.001), clinical improvement status in the first 14 days (HR 1.02, CI 0.97-1.08; p = 0.001) and duration of neutropenia (HR 2.67, CI 2.26-3.08; p = 0.019) were independent risk factors associated with 28-day mortality.

Mortality due to resistant microorganisms is high in hematologic patients during stem cell transplantation and non-transplant period. Age, pneumonia and need for mechanical ventilation and duration of neutropenia are the most important mortality indicators in hematologic patients. Ceftazidime-avibactam is an effective treatment option in appropriate patients and the clinical response will be better if it can be started before the need for mechanical ventilation develops.