This medication is used to treat certain types of arthritis (rheumatoid arthritis, arthritis of the spine, psoriatic arthritis), certain bowel diseases (Crohn's disease, ulcerative colitis), and a certain severe skin disease (chronic plaque psoriasis). In these conditions, the body's defense system (immune system) attacks healthy tissues. Infliximab works by blocking the actions of a certain natural substance (tumor necrosis factor alpha) in the body. This helps to decrease swelling (inflammation) and weaken your immune system, which slows or stops the damage from the disease. This monograph is about the following infliximab products: infliximab, infliximab-abda, infliximab-axxq, and infliximab-dyyb.