A 71-year old man was admitted to the hospital after getting very dizzy upon rising from the toilet seat. At that time, his pulse was racing and he remembers that his stool looked very different than usual. Over the last 4 or 5 weeks before the incident, the patient self-medicated with highdose ibuprofen TID to control some pain in his hips. What is the mechanism of action for nonsteroidal anti-inflammatory drugs (NSAIDs) to cause gastrointestinal bleeding?

Question

Quizplus · Accepted Answer

NSAIDs inhibit cyclooxygenase (COX) enzymes, which are responsible for the production of prostaglandins that protect the gastric mucosa. This inhibition can lead to gastrointestinal bleeding.  Nonsteroidal anti-inflammatory drugs inhibit cyclooxygenase and consequently inhibit (not promote, choice E) synthesis of prostaglandins. In the stomach, prostaglandins have a cytoprotective effect through inhibition of acid secretion, enhancement of mucosal blood flow, and stimulation of bicarbonate and mucus secretion. Inhibiting these processes can cause stomach ulcers and bleeding such as described in the case.

A 71-Year Old Man Was Admitted to the Hospital After