How does aspirin cause peptic ulcers?

Members of the non-steroidal anti-inflammatory group of drugs (NSAIDs) are amongst the most 'ulcerogenic' of medications. Why? As this post explains, the NSAIDs work by inhibiting cycloxygenase, an enzyme crucial to prostaglandin production. The connection with the stomach is that prostaglandins have at least three protective effects on the stomach lining:

• Prostaglandins stimulate mucus secretion to coat the stomach


• Prostaglandins cause the secretion of bicarbonate, a base that neutralises excess stomach acid.


• Prostaglandins cause vasodilatation, increasing blood flow the the stomach's mucosal layer and thereby ensuring its rapid healing.

It doesn't take a genius to notice that a sustained deficiency of prostaglandins (as occurs with NSAID use for more than a week or two) therefore predisposes you to peptic ulcers. If it is really necessary to give NSAIDs, some form of antacid medication must be given too (e.g. simply antacids, or even proton pump inhibitors).