Pharmacokinetics of fazadinium in patients with renal failure.

The serum concentrations of fazadinium and its metabolites were measured in 14 surgical patients with end-stage renal failure and in 11 patients free from kidney disease undergoing abdominal surgery. A two-compartment open model was used in the pharmacokinetic analysis of the data. The elimination half-life (T 1/2 beta) was prolonged by 60% in patients with renal failure (from 85 to 140 min) and corresponded to a 30% decrease of the plasma clearance. The plasma concentration of the metabolites never exceeded 7% of the unchanged fazadinium. These results suggest that the duration of action will be less prolonged for fazadinium than for other non-depolarizing neuromuscular blocking drugs in patients with renal failure. A supplementary biliary pathway appears to be a possible explanation for the rapid elimination of fazadinium, even in patients with renal failure.