Pharmacokinetics of cyclophosphamide after prolonged low dose treatment in ovarian cancer patients.

We have studied Cyclophosphamide (Cy) pharmacokinetics in 9 patients after their first intravenous dose of 100 mg, and in 9 patients after 6--13 months of continual treatment with the same dose every day. The half-life of Cy was shorter (p less than 0.05) in the latter group, the Co was greater (less than 0.01) and the Vd was clearly less (p less than 0.01). The AUC was unchanged.