Related Experiment Video
Updated: May 30, 2025

Multiplex Therapeutic Drug Monitoring by Isotope-dilution HPLC-MS/MS of Antibiotics in Critical Illnesses
Published on: August 30, 2018
Unveiling results and insights from multinational, multicenter Study of Prescribing patterns and Effectiveness of
Alex Soriano1, David L Paterson2, Florian Thalhammer3
1Hospital Clinic, Barcelona, Spain.
Objectives:
Antibacterial-resistant gram-negative hospital-acquired infections result in significant morbidity and mortality. In clinical trials, ceftolozane/tazobactam (C/T) has been effective against these infections; however, real-world findings are limited.
Methods:
SPECTRA was a global, retrospective, observational inpatient study of adults treated with C/T for ≥48 h, conducted between 2016 and 2020. The primary objective was to describe real-world utilisation of C/T: socio-demographic, clinical characteristics, prescribing patterns, clinical outcomes, and healthcare resource utilisation in hospitalised patients treated with C/T.
Results:
In total, 617 patients from 7 countries met inclusion criteria. Most (82.7%) had ≥1 comorbidity. The most common medical conditions where C/T was used were pneumonia (29.5%), sepsis (20.4%), complicated intra-abdominal infection (15.1%), and complicated urinary tract infection (14.4%). The most common pathogens were Pseudomonas aeruginosa (87.4%) and Escherichia coli (8.2%). Median C/T treatment duration was 11 days. Clinical success occurred in 67.3% of patients (including those with 'unknown' status in the denominator). In a separate analysis that excluded those with 'unknown' status, clinical success ranged from 94.1% in patients with bacteraemia to 58.9% with sepsis. Overall, 18.8% of patients had documented microbiologic response. All-cause in-hospital mortality was 21.2%; infection-related mortality was 7.6%. Median hospital length of stay was 42 days (30 days for those who received early C/T therapy [before pathogen identification] vs. 48 days for definitive therapy [after identification]).
Conclusions:
These data elucidate real-world utilisation and prescribing patterns of C/T in a diverse patient population with complex medical conditions and various profiles of pathogen resistance between 2016 and 2020.

