Table 2. Pharmacokinetics and metabolism of ifosfamide in the patients studied.
|
IFO PK
|
Metabolite AUCs (μM h)
|
|||||||
|---|---|---|---|---|---|---|---|---|
| Regimen | N | Clearance (l h−1 m−2) | t1/2 (h) | Vd (l kg−1) | IFO | CXI | 3DCI | 2DCI |
| 72 h CI | 8 | 6.2 (2.6–7.4) | 2.4 (1.3–5.6) | 0.44 (0.16–1.82) | 5135 (4668–13247) | 941 (542–3443) | 1868 (554–5342) | 1166 (207–3011) |
| 3 or 1 h infusion day 1 | 11 | 4.1 (2.6–5.8) | 4.7 (1.9–8.3) | 0.89 (0.35–1.63) | 6011 (4009–9488) | 511 (47–1700) | 1702 (521–3164) | 1337 (326–2678) |
| 3 or 1 h infusion day 3 | 8 | 6.1 (3.0–7.8) | 2.9 (2.0–4.6) | 0.92 (0.53–1.33) | ||||
IFO-PK=pharmacokinetic parameters for ifosfamide; t1/2=half-life; Vd=volume of distribution.
For metabolite abbreviations see text.
AUCs for IFO and metabolites in patients receiving a fractionated dosing over 3 days are given cumulatively over the cycle of chemotherapy to allow for comparison with data from patients receiving the same dose as a continuous 72 h infusion (CI). AUCs are dose adjusted in those patients receiving only 2 days of therapy. Data have been combined for those patients receiving fractionated doses of ifosfamide by either 1 or 3 h infusion.