Table 4. Population pharmacokinetic parameters for tulathromycin in 3-week old vs. 6-month old calves with respiratory disease.
| Population Values—Final NLME Model | ||||
|---|---|---|---|---|
| Parameter | Units | Estimate | Stderr | CV% |
| TMAX | h | 2.0 | 1.6 | 109.7 |
| CMAX | μg/mL | 1.3 | 0.9 | 81.5 |
| θV | L/kg | 3.7 | 1.06 | 55.0 |
| θV2 | L/kg | 19.6 | 2.9 | 71.5 |
| θV3 | L/kg | 1.3 | 0.56 | 49.9 |
| Cl | L/kg/h | 0.20 | 0.30 | 67.8 |
| Cl2 | L/kg/h | 0.24 | 0.38 | 78.2 |
| CL3 | L/kg/h | 1.03 | 0.12 | 11.5 |
| T½* | h | 100.3 | 7.0 | 69.8 |
Population values from NLME model and median and range of PK parameters from compartmental analysis after single S.C. injection of 2.5 mg/kg tulathromycin in 3-week-old vs. 6-month-old calves with induced respiratory disease with P. multocida.
* Indicates significantly different by t-test (P < 0.05).