Table 2.
Practice patterns for therapeutic drug monitoring of intravenous busulfan.
| Characteristic | n (%) |
|---|---|
| Target busulfan exposure metric used to guide dosing | |
| AUC (µM × min) | 419 (57) |
| CSS (ng/mL) | 310 (43) |
| Number of different target busulfan AUCs for 5 most common diseases | |
| AML/MDS | 39 |
| CID | 31 |
| CML/JMML | 26 |
| Pediatric solid tumor | 21 |
| Histiocytic disorder | 17 |
| Number of AUCs drawn per patient | |
| 1 | 622 (85) |
| 2 | 94 (13) |
| 3 | 13 (2) |
| Number of samples obtained with initial AUC estimation | |
| 3 | 2 (0.3) |
| 4 | 72 (10) |
| 5 | 82 (11.3) |
| 6 | 44 (6.0) |
| 7 | 524 (71.9) |
| 8 | 5 (0.7) |
| Pharmacokinetic model to characterize busulfan AUC0−∞a | |
| Noncompartmental | 308 (42.6) |
| 1-compartment | 242 (33.4) |
| 2-compartment | 173 (24.0) |
| Dose recommendation for subsequent busulfan doses to achieve target AUCb | |
| Decrease | 183 (25.3) |
| No change | 176 (24.3) |
| Increase | 364 (50.3) |
a
n = 723 because 6 concentration-time profiles could not be modeled.
b
n = 723 because no dose was recommended for 6 patients either due to inability to model data or busulfan administration had finished by the time pharmacokinetic results were available.