Effect of hemodialysis on topotecan disposition in a patient with severe renal dysfunction

The pharmacokinetics of topotecan have been extensively studied in patients with normal renal function and there is one study of patients with mild to moderate renal insufficiency. However, the effect of hemodialysis on topotecan disposition has not been reported. The objective of this study was to characterize the disposition of topotecan in a patient with severe renal insufficiency receiving hemodialysis. Topotecan lactone disposition was characterized in a patient on and off hemodialysis. The topotecan lactone clearance determined after administration of topotecan alone and with hemodialysis was 5.3 l/h per m(2) vs 20.1 l/h per m2 respectively. At 30 min after the completion of hemodialysis, the topotecan plasma concentration obtained was greater than that measured at the end of hemodialysis (i.e. 8.0 ng/ml vs 4.9 ng/ml), suggesting a rebound effect. The topotecan terminal half-life off dialysis was 13.6 h, compared with an apparent half-life determined during hemodialysis of 3.0 h. These results demonstrate that topotecan plasma clearance while on hemodialysis increased approximately fourfold. Hemodialysis may be an effective systemic clearance process for topotecan and should be considered in selected clinical situations (e.g. inadvertent overdose, severe renal dysfunction).