Pharmacokinetic profile of droxicam.

Abstract

Droxicam is a new non-steroid anti-inflammatory drug that is a pro-drug of piroxicam. The pharmacokinetics of droxicam, both as a single 10mg dose and as a multidose regimen of 10 and 20mg/day for 20 consecutive days, have been studied in healthy volunteers. Since transformation into piroxicam takes place in the gastrointestinal tract, unchanged droxicam was not detected in plasma. After a single 10mg dose the value of Tmax was higher than that reported for piroxicam (10mg). This effect is a consequence of the process of transformation of droxicam into piroxicam. The remaining pharmacokinetical parameters studied were similar to those reported in other studies on piroxicam (10mg). After multiple oral administration at a dose of 10 and 20mg/day, absorption kinetics of droxicam were delayed with respect to those of piroxicam. The other pharmacokinetical parameters studied showed no statistically significant differences between droxicam and piroxicam. Absorption and elimination of droxicam are independent of the administered dose and the bioavailability of droxicam and piroxicam was equal. The influence of gastric emptying on droxicam pharmacokinetics and bioavailability has been investigated in healthy volunteers. Gastric emptying was experimentally modified by use of propantheline and metoclopramide. Following modification of gastric emptying, only Tmax underwent significant increase (P < 0.05). Absorption rate of droxicam was modified but elimination and bioavailability did not suffer modification in conditions of altered gastric emptying.