title: Piroxicam and 5'-hydroxypiroxicam kinetics following multiple dose administration of piroxicam.
abstract: 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 micrograms/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 (Css) of piroxicam (7.0 micrograms/ml) were significantly higher than predicted from a previously reported single dose study (5.3 micrograms/ml).
mesh_terms: D000328:Adult; D001711:Biotransformation; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D010894:Piroxicam / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism*; D011485:Protein Binding; D013997:Time Factors
chemical_list: D010894:Piroxicam; C051024:5'-hydroxypiroxicam