Effect of plasma exchange on flumequine pharmacokinetics: comparison with control kinetics

The effect of plasma exchange (PE) on the pharmacokinetics of flumequine (Apurone) was studied in eight patients receiving a single oral dose of 800 mg. The maximum concentration (38 micrograms/ml) and time to maximum concentration (2.6 h) values were not significantly altered by PE beginning 3 h after administration of flumequine. There was no change in the terminal elimination half-lives (6.6 h), in the steady-state volume of distribution (29 L), or in the apparent plasma clearance (2.5 L/h). By contrast, PE decreased the mean residence time by 30% (14.3 +/- 4.1 h without PE; 9.88 +/- 1.36 h with PE; p less than 0.05). The amount of flumequine extracted by PE (72 mg) was proportional to the plasma concentration at the beginning of the exchange. The elimination half-life during PE (3.15 +/- 1.23 h) decreased by 40%. Renal clearance (0.3 L/h) was not affected. PE only partially modifies the pharmacokinetics of flumequine administered in a single oral dose before PE.