Tenoxicam-induced gastropathy in the rat: a comparison with piroxicam and diclofenac sodium, and the inhibitory effects of ranitidine and sucralfate

The ulcer-inducing potential, indicated by the oral dose that induced gastric ulcers in 50% of rats, was higher for tenoxicam (10.2 mg/kg) than for diclofenac sodium (34 mg/kg, equivalent to 6.8 mg/kg tenoxicam) or piroxicam (6.2 mg/kg). The mean lesion scores, a measure of the intensity of ulceration, using 16 and 32 mg/kg tenoxicam given orally were 3.6 +/- 3.4 and 8.7 +/- 7.3, respectively, compared with 9.6 +/- 6.4 and 24.7 +/- 10.5, respectively, for similar oral doses of piroxicam; the differences were statistically significant (P less than 0.05 and P less than 0.001, respectively). The mean lesion score for 32 mg/kg tenoxicam was also significantly (P less than 0.05) less than that for 160 mg/kg diclofenac sodium: 8.7 +/- 7.3 compared with 14.8 +/- 8.1. Ranitidine (20 40 mg/kg) and 260-520 mg/kg sucralfate but not 4 mg/kg ranitidine strongly inhibited ulceration induced by 32 mg/kg tenoxicam.