TABLE 3.
Time during which β-lactams remains >90% stable at the highest concentration tested (see )
| Drug(s) | Time (h, min)a at:
|
|
|---|---|---|
| 37°C | 25°C | |
| Aztreonam | >24 | ND |
| Piperacillin | 21, 40 | ∼30 |
| Piperacillin + tazobactam | >24 | ≫72b |
| Azlocillin | >24 | ≫72b |
| Mezlocillin | 14 | 46, 30 |
| Ceftazidime | 8 | 24 |
| Cefepime | 13 | 20, 30 |
| Cefpirome | 7, 15 | 23, 40 |
| Imipenem + cilastatin | 2, 45 | 3, 30 |
| Meropenem | 1, 50 | 5, 15 |
| Faropenem | >24 | ∼80 |
a
Decays were monitored for 24 h; the slope was calculated by linear regression and used to determine the 90% stability time point. All data were rounded to the closest 15-min value. ND, not determined.
b
90% stability for at least 72 h, but the slope was too weak to calculate the 90% intercept value with accuracy from the 24-h decay data.