CYP-substrate (CYP 2C9) .Two references consider it (probably) safe.

(To be edited, initial data ST OCT 04) Tabl. 10-30 mg/d. analgetic, antipyretic och anti-inflammatory oxicam derivative used in arthrosis, RA and Mb Bechterew. Metabolized by hydroxylation of the side chain pyridyl ring (CYP 2C9) and conjugation with glucuronic acid. Very weak inhibitor of CYP 3A4. South African list: use with care. French list: authorized.

Uneventful use reported in 8 patients with acute porphyria.