Tolmetin (30,100 mg/kg; gavage; single dose or twice daily for 3 and 14 days) shows 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. Tolmetin (5 mg/kg twice a day for 5 days) pre-treatment considerably attenuates quinolinic acid (QA)-induced neurotoxicity.