COX-2 inhibitors are a type of nonsteroidal anti-inflammatory drug that directly affects COX-2, an enzyme involved in inflammation and associated pain. The use of COX-2 inhibitors was evaluated in patients with cancer related to the development of palmar-plantar erythrodysesthesia (PPE) skin effects and as a potential treatment for oral mucositis. Celecoxib, a type of COX-2 inhibitor, has also been studied for its impact on symptoms of depression in patients with cancer.