Comparative effects of tolfenamic acid and acetylsalicylic acid on human gastric mucosa. A double-blind crossover trial employing gastroscopy, extern gastrocamera and multiple biopsies.

A comparative study has been made of the effects of tolfenamic acid (Clotam) and acetylsalicyclic acid on the gastric mucosa in 10 healthy volunteers. The effects were evaluated by means of gastroscopy, photography of the gastric mucosa, and multiple biopsies. The schedule was for a randomized, double-blind crossover trial involving two drug-administered periods of one week's duration separated by an interval of at least 3 weeks. On each day of the drug-administration weeks either tolfenamic acid 600 mg or acetylsalicyclic acid 3 g was administered as three divided doses, taken with meals. Gastroscopy was performed prior to and after each week of drug administration. Subjective side effects were recorded during the therapy periods; haematemesis occurred in 2 volunteers taking acetylsalicyclic acid. The absence of gastritis in each subject during treatment with tolfenamic acid was confirmed both gastroscopically and histologically. In contrast, 6 out of 10 volunteers developed mild superficial acute gastritis after ingestion of acetylsalicyclic acid. The difference in effect between the two treatments on the gastric mucosa was statistically significant(p less than 0.05). The findings of this study are comparable to those of other studies and it is concluded that tolfenamic acid, in the relatively high dosage employed in this trial, is free from any irritant effect on the gastric mucosa.