The effect of haemodialysis on the pharmacokinetics of tenoxicam in patients with end-stage renal disease.

We have studied the pharmacokinetics of tenoxicam after single and multiple oral doses of 20 mg in five patients (2 men and 3 women) with end-stage renal disease undergoing haemodialysis. After a single dose, tenoxicam had a half-life (t1/2) of 33 h, an apparent clearance (CL.f-1) of 4.3 ml.min-1, and an apparent volume of distribution (Vz.f-1) of 11.81. The maximum tenoxicam concentration (Cmax) was 4.3 mg.l-1 at a median tmax of 1.7 h. There were no significant differences between the values calculated from the pre- or post-dialyser port plasma samples. Tenoxicam plasma concentrations measured during once daily dosing before and after haemodialysis showed that tenoxicam does not accumulate. Our findings suggest that dosage adjustment may not be required in patients with end-stage renal disease on haemodialysis taking tenoxicam.