Table 3.
Mean (Range) of CrCl and Timing Effects on Vancomycin Trough Concentrations ≥10 mg/L Measured ≥0.5 h Before Next Dose.
| CrCl Group (ml/min) |
Number of Troughs (n) |
CrCla (ml/min) | Measured Trough (mg/L) |
Estimated True Troughb (mg/L) |
Trough Differencec (mg/L) |
|
|---|---|---|---|---|---|---|
| Trough Measured ≥2 h Prior to Next Dose | ≥60 | 11 | 88.3 (64–126) |
17.5 (13.6–22.7) |
12.9 (7.5–19.1) |
4.6 (2.0–6.6) |
| <60 | 12 | 37.4 (16–59) |
16.3 (10.3–29.4) |
14.2 (9.2–25.2) |
2.1 (0.6–6.4) |
|
| Trough Measured >0.5 and <2 h Prior to Next Dose | ≥60 | 15 | 87.7 (63–123) |
16.4 (10.2–26) |
15.2 (9.3–22.8) |
1.2 (0.5–3.2) |
| <60 | 10 | 43.1 (27–59) |
16.0 (10.3–23.6) |
15.4 (9.8–23.1) |
0.6 (0.4–0.9) |
|
| Total | 48 | 65.5 (16–126) |
16.6 (10.2–29.4) |
14.5 (7.5–25.2) |
2.1 (0.4–6.6) |
|
a CrCl estimate via the Cockcroft-Gault equation [10]; b Estimate of the “true” trough based on extrapolating the measured trough to what it would have been at the time of the next scheduled dose, using the CrCl-based estimation of elimination rate constant from Matzke [11].; c The difference between measured trough and the estimate of what the true trough would have been.