Table 1B.
Population baseline and therapeutic drug monitoring data.
| β lactam | n (%) | Total concentrationa (mg/L) | Unbound concentrationa (mg/L) | FC > 4 × MICb |
|---|---|---|---|---|
| Cefotaxime (6 g/24 h) | 13 (63) | 23 [17–26] | 18.4 [13.6–20.8] | 100% |
| Cefepime (6 g/24 h) | 3 (16) | 29 [29–81.2] | 23 [23–65] | 100% |
| Piperacillin/tazobactam (12 g/24 h) | 4 (21) | 42 [34–67] | 33.6 [25.3–53.6] | 100% |
Plasma concentrations of β-lactams were measured directly using a validated and previously published HPLC assay.
a
Total concentration and free concentration (FC) (estimated using previous published data regarding the percentage of unbound fraction: 80% for each β-lactam) were obtained after 24 hours of continuous administration, at steady state.
b
Adequation of FC > 4 × MIC was based on the EUCAST highest epidemiological cut-off (ECOFF) values. The species taken into account in community-acquired pneumonia were Staphylococus aureus, Enterobacteriaceae and Streptococcus pneumoniae.