Determinants of the short-term gastric damage caused by NSAIDs in man

Background The short-term gastric damage seen with non-steroidal anti-inflammatory drugs (NSAIDs) in man may involve inhibition of cyclooxygenase (COX-1) and COX-2 as well as the topical irritancy, which is dependant on the acidity (pKa) and/or lipophilicity (log P-7.4). Aim To study the quantitative relationship between NSAID-induced short-term gastric damage, their physicochemical properties and contrasting roles of COX-1 and COX-2 inhibition. Methods We identified studies that allowed a qualitative comparison of the gastric injury (Lanza scores) induced by NSAIDs with their pKa and log P-7.4. Damage was correlated with gastric COX inhibition and potency to inhibit COX-1 and 2 and their COX-2/COX-1 selectivity ratio. Results The gastric damage correlates significantly with pKa (r = -0.69; P < 0.01), log P (r = -0.58, P < 0.05) and potency of the NSAIDs to inhibit COX-1 (r = -0.61, P < 0.02), but not with COX-2 inhibition or COX-2/COX-1 selectivity. Conclusions Against a background of COX-1 and COX-2 inhibition, the physicochemical properties of NSAID appear to play an important role in short-term gastric damage.