TABLE 5.
Piperacillin population pharmacokinetic parameter estimates obtained by NPEM3 analysisa
| Model and parameter | Km (mg/liter) | Vmax (mg/h) | kel (h−1) | Vc (liters) | k12 (h−1) | k21 (h−1) |
|---|---|---|---|---|---|---|
| MM | ||||||
| Mean | 92.3 (85.6) | 2,284 (1,046) | NA | 13.67 (3.28) | 0.600 (0.369) | 0.410 (0.280) |
| Median | 57.8 (74.8) | 1,904 (1,009) | NA | 14.08 (2.98) | 0.630 (0.413) | 0.367 (0.194) |
| MM-kel combination (no descriptors for kel) | ||||||
| Mean | 83.8 (94.3) | 1,836 (785) | 0.0033 (0.0027) | 13.78 (4.00) | 1.030 (0.950) | 0.433 (0.827) |
| Median | 44.9 (62.1) | 1,401 (859) | 0.0023 (0.0031) | 11.75 (4.40) | 0.575 (1.129) | 0.825 (0.750) |
| MM-kel combination (kel as a function of CLCR)b | ||||||
| Mean | 77.2 (117.0) | 1,572 (1,150) | NA | 10.99 (3.07) | 1.327 (1.222) | 0.810 (0.580) |
| Median | 32.9 (64.6) | 1,151 (655) | NA | 10.75 (2.32) | 0.950 (1.120) | 0.591 (0.598) |
| Linear kel | ||||||
| Mean | NA | NA | 0.846 (0.197) | 23.09 (13.45) | 0.883 (1.181) | 0.846 (0.197) |
| Median | NA | NA | 0.953 (0.209) | 17.59 (10.87) | 0.447 (0.847) | 0.953 (0.209) |
a
Parameters are expressed as follows: mean and median, standard deviation, as defined in User Manual for Version 10.7 of the USC*PACK Collection of PC Programs; NA, not applicable.
b
Calculated as 0.01 + (ks × CLCR), with ks fixed at 0.0052 h−1.