Effect of acetaminophen on human gastric mucosal injury caused by ibuprofen.

Acetaminophen has been proposed as an agent which protects the gastric mucosa against damage induced by aspirin and other non-steroidal anti-inflammatory agents. In order to evaluate this proposal further, 45 normal human volunteers were divided into three groups (n = 15); group one received ibuprofen 2400 mg daily (600 mg qid); group two received acetaminophen 3900 mg daily (975 mg qid) and group three received both drugs at the same dosages. There was no significant difference in the mucosal injury scores noted at endoscopy between the ibuprofen and the ibuprofen-acetaminophen group. The acetaminophen group had virtually no observed mucosal injury and this was statistically significant in comparison with the other groups (p less than 0.01). We conclude that contrary to previously reported studies using single doses of aspirin, acetaminophen failed to decrease the mucosal injury seen with ibuprofen when given for a period of seven days in combination with acetaminophen.