Lornoxicam-d4 is intended for use as an internal standard for the quantification of lornoxicam by GC- or LC-MS. Lornoxicam is a COX inhibitor and non-steroidal anti-inflammatory drug (NSAID) with anti-inflammatory and analgesic properties. It inhibits production of thromboxane B2 from arachidonic acid in HEL human erythroleukemic cells, which endogenously express COX-1, as well as inhibits LPS-induced formation of prostaglandin F1α from arachidonic acid in Mono-Mac-6 cells, which endogenously express COX-2. Lornoxicam reduces LPS-induced production of nitric oxide and IL-6 in cell-based assays with IC50 values of 65 and 54 µM, respectively. It reduces carrageenan-induced paw edema in rats when administered intravenously at doses ranging from 0.1 to 9 mg/kg. Formulations containing lornoxicam have been used in the management of postoperative pain.