Meloxicam (10 μM) was incubated in 0.1 M Tris buffer, pH 7.4, at 37°C with human CYP 3A4 (0.5 mg of protein/ml), an NADPH-generating system (consisting of 1.2 mM NADP, 0.7 U of glucose 6-phosphate dehydrogenase/ml, 8 mM glucose 6-phosphate), and in the presence of different compounds at two concentrations (10 and 100 μM) for 60 min (mean of duplicate experiments), control 1.7 pmol/min/mg protein. Values were corrected for basic activity (0.14 pmol/min/mg protein) of control microsomes not expressing CYP 3A4.