Piroxicam (20 mg once daily) was administered orally to six healthy young volunteers for 15 days. Trough steady-state levels of piroxicam and 5-hydroxypiroxicam were 5.5 and 1.2 µg/ml, respectively. Piroxicam's plasma half-life (54.9 h) was significantly shorter than that of 5-hydroxypiroxicam (70.5 h). Percent unbound piroxicam and 5-hydroxypiroxicam in plasma at steady-state averaged 1.10 and 8.07 respectively. An average of 25.2% of the dose was recovered in urine as 5-hydroxypiroxicam; approximately two-thirds (17.2%) in the form of the glucuronide conjugate. Average steady-state plasma levels (C_ss) of piroxicam (7.0 µg/ml) were significantly higher than predicted from a previously reported single dose study (5.3 µg/ml).