COMPARATIVE GASTRIC TOLERABILITY OF LYSINE ACETYLSALICYLATE AND CONVENTIONAL ASPIRIN IN THE DOG

The gastric tolerability of low dose conventional aspirin (acetylsalic ylic acid) was compared with that of lysine acetylsalicylate in the do g. A total of 14 dogs were allocated to aspirin 250mg (n = 2) or 500mg (n = 4) tablets, lysine acetylsalicylate powder (LAS) corresponding t o 250mg aspirin (n = 2) or to 500mg aspirin (n = 4), and to plain vehi cle (n = 2). Animals were sacrificed after general anaesthesia. Macro- and microscopic examinations of gastric and duodenal mucosae were per formed 3 or 5 hours after single dose oral administration. No signific ant duodenal lesions were found. On the gastric mucosa, vascular chang es (oedema and microhaemorrhages) and foveolar atrophy were observed w ith a similar frequency and intensity in all groups receiving aspirin or LAS. Mucosal erosions with coagulative necrosis occurred only in th e aspirin groups. Thus, the gastrotoxicity of aspirin at relatively lo w doses is apparent with a standard aspirin formulation, but seems sub stantially less when using a highly soluble acetylsalicylate salt.