Tolmetin sodium dihydrate, a non-steroidal anti-inflammatory drug (NSAID), is a potent and orally active inhibitor of COX (cyclooxygenase). Its IC 50 values for human COX-1 and COX-2 are 0.35 μM and 0.82 μM, respectively [1] [2].

Tolmetin sodium dihydrate (0.25 mM) does not reduce lipid peroxidation in rat brain homogenate. Tolmetin (0.25, 0.5, 0.75, 1 mM) shows radical scavenging properties but without superoxide anion generation in rat brain homogenat [3]. Tolmetin sodium dihydrate (0.001-100 μM) shows anticancer activity againts HT-29 colon cancer cell line in a dose-dependent manner [4]. Tolmetin sodium dihydrate (0-100 μM) shows no effect on osteoblast growth [5].

Tolmetin sodium dihydrate (30,100 mg/kg; gavage; single dose or twice daily for 3 and 14 days) exhibits maximal ulcerogenic effect 4 h after the single dose, while potently decreases after 3 and 14 days of repeated administration in male Wistar rats weighing 180-200 g. Tolmetin causes gastric lesions in 100 mg/kg [2]. Tolmetin sodium dihydrate (5 mg/kg twice a day for 5 days) pre-treatment considerably attenuates quinolinic acid (QA)-induced neurotoxicity [3].