In the management of a client with acute gastritis, which medication is likely to cause irritation and should be avoided?

Indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), is known to cause irritation of the gastric mucosa. Its mechanism of action involves inhibiting the synthesis of prostaglandins, which play a protective role in maintaining the gastric lining. The reduction in prostaglandins can lead to increased gastric acid secretion and decreased mucosal defenses, making the stomach more susceptible to irritation and damage. This is particularly concerning in clients with acute gastritis, where the mucosa is already inflamed and vulnerable.

In contrast, antacids, proton pump inhibitors, and H2 blockers are typically used to manage gastric acidity and provide relief from discomfort associated with gastritis. These medications either neutralize stomach acid (antacids) or reduce its production (proton pump inhibitors and H2 blockers), aiding in the healing process of the gastric mucosa rather than exacerbating irritation. Therefore, indomethacin should be avoided in this context to prevent further gastric irritation and complications.