Does the use of new cephalosporins follow the authorised, financed and approved indications? A study of their use in routine clinical practice in a tertiary hospital.

Objectives: To evaluate the appropriateness of ceftazidime-avibactam (C-A), ceftolozane-tazobactam (C-T) and ceftaroline prescriptions according to European Medicines Agency (EMA)/Spanish Agency of Medicines and Medical Devices (AEMPS) approved indications, financed indications in the Spanish health system and hospital Infection Commission (IC) recommendations in a tertiary hospital.

Methods: Observational, descriptive and retrospective study of inpatients aged ≥18 years, who were prescribed the above-mentioned antimicrobials during the period January-December 2020. Variables obtained were demographic (sex and age), pharmacological (antibiotic, use - empiric or targeted, indication) and microbiological (sensitivity testing and antibiotic tested) data.

Results: A total of 79 patients were included. C-A (n=40): 67.5% of patients were male, with a mean age of 61 (range 22-87) years. Empiric treatment was applied in 30% of the cases (n=12). De-escalation in 33.33% of individuals. Sensitivity testing was done in 92.86% of patients, including C-A in 57.69% of them. C-T (n=19): 89.47% of patients were male, with a mean age of 65 (range 18-82) years. An empiric approach was followed in 5.26% of subjects; de-escalation was performed in all cases due to culture with multidrug-resistant (MDR) . Sensitivity testing was carried out in 100% of patients, including C-T in 26.32% of them. Ceftaroline (n=20): 70% of patients were male, with a mean age of 55.5 (range 23-79) years. Empiric treatment was applied to 30% of cases. In 50% of these subjects de-escalation was done. Sensitivity testing was done in 92.85% of them, but in none with ceftaroline. Regarding the percentage of appropriateness: approved EMA/AEMPS indications: C-A: 100%; C-T: 84.21%; ceftaroline: 75%; financed indications in the Spanish health system: C-A: 85%; C-T: 100%; ceftaroline: 15%; IC: C-A: 60%; C-T: 57.9%; ceftaroline: 15%.

Conclusions: Our results highlight the importance of stewardship programmes in the decision-making process and in the follow-up of patients with infections caused by MDR microorganisms.