Single- and multiple-dose pharmacokinetics, kidney tolerability and plasma protein binding of tenoxicam in renally impaired patients and healthy volunteers

The 20 mg single-dose and 12 days repeated-dose pharmacokinetics of tenoxicam and the 5-OH-tenoxicam metabolite have been evaluated in healthy volunteers and two groups of patients with different degree of renal impairment, in total 20 subjects. Concomi tantly, the plasma protein binding of tenoxicam and the effect of treatment on renal function were evaluated. The pharmacokinetics and plasma protein binding of tenoxicam and the pharmacokinetics of the metabolite are increasingly changed in patients wi th a creatinine clearance below 40 ml/min. A decreased binding of tenoxicam in low clearance patients is probably the reason for a faster elimination of tenoxicam in this group rather than a higher intrinsic hepatic metabolic activity. The study did not bring forward any new data indicating any adverse effect of tenoxicam on renal function.