Acetylsalicylic acid-induced biochemical changes in gastric juice: a failure of adaptation?

ABSTRACT

BACKGROUND: Acetylsalicyclic acid (ASA) causes gastric mucosal damage which diminishes with continued use due to adaptation. METHODS: To determine the net effect of these processes on the gastric juice, we estimated acid, osmolality, bicarbonate concentration in nonparietal gastric juice, calcium, potassium and sodium in 18 patients (9 men; mean age 32 years, range 20-46) with irritable bowel syndrome, before and after 600 mg of ASA taken post-cibum thrice daily for 4 weeks. Osmolality was determined by an osmometer, acidity by titration, and Na+, K+ and Ca++ using a sodium-potassium-calcium analyzer; bicarbonate was derived from the two-component model of Feldman. RESULTS: Gastric juice K+ and Na+ increased significantly from mean (SE) 14.6 (0.5) and 197.5 (16.3) to 16.7 (0.4) and 256.8 (18.1) mEq/L, respectively. The other parameters remained unchanged. CONCLUSION: After four weeks of ASA ingestion there is a dichotomy of gastric mucosal injury and adaptation, with preservation of acid secretion but continued loss of Na+ and K+.