Background and importance The acquisition of resistance by bacteria has meant that new antimicrobials appear. Ceftazidime–avibactam is a restricted antibiotic that is used in multiresistant infections that put the patient‘s life at risk.

Aim and objectives To evaluate the effectiveness of ceftazidime–avibactam as a treatment for multidrug resistant infections in a third level hospital.

Material and methods This was a before and after study in patients with multidrug resistant infections treated with ceftazidime–avibactam between April 2018 and April 2019. Those <18 years of age and patients who did not have the main study variables were excluded.

The main variable of our study was C reactive protein (CRP) before and after treatment. Secondary variables included age, sex, weight, dosage and isolated microorganism. An initial descriptive analysis was performed with mean (SD) or median (IQR, P25–P75) for numerical variables or absolute frequencies for nominal variables. For statistical analysis, the Wilcoxon test of paired measures was used to determine if there were differences in median CRP values before and after antibiotic treatment. The analyses were performed using the SPSS/PC statistical programme (V.24.0 for Windows, SPSS Inc, Chicago, Illinois, USA).

Results Thirty-six patients were treated with ceftazidime–avibactam from April 2018 to April 2019, of whom 32 were studied. Of these, 21 were men, average age was 63±11 years and average weight was 71±20 kg. The most common dosage was 2 g every 8 hours (25) and the most prevalent microorganism was Klebsiella pneumoniae (25).

The median initial CRP was 8.85 mg/dL (1.53–17.27) while the median final CRP was 3.29 mg/dL (0.59–6.78). Statistically significant differences were found in median CRP before and after antibiotic treatment (z=−3.35; p=0.001).

Conclusion and relevance Ceftazidime–avibactam was found to be effective in patients presenting with multidrug resistant infections as it significantly reduced CRP, a marker used to monitor infections.

References and/or acknowledgements No conflict of interest.