NSAIDS have antipyretic activity and can be used to treat fever.   Fever is caused by elevated levels of prostaglandin E2 , which alters the firing rate of neurons within the hypothalamus that control thermoregulation.   Antipyretics work by inhibiting the enzyme COX, which causes the general inhibition of prostanoid biosynthesis ( PGE2 ) within the hypothalamus .   PGE2 signals to the hypothalamus to increase the body's thermal set point.   Ibuprofen has been shown more effective as an antipyretic than paracetamol (acetaminophen).   Arachidonic acid is the precursor substrate for cyclooxygenase leading to the production of prostaglandins F, D & E.
These changes alter the intrinsic mechanical properties of articular cartilage and produce swelling. 25 The articular cartilage, having lost some of its compressive ability under load, further degenerates. As the surface fibrillation progresses, the articular defects penetrate deeper into the cartilage until the cartilage is lost. The increased pressure on the subchondral bone causes it to thicken. Often bone cysts form deep to the eburnated areas. Eventually, bony nodules or osteophytes form at the periphery of the cartilage surface. All of these changes account not only for the pathology found on radiographs or histologically (findings under the microscope), but also for the joint pain, tenderness, loss of motion and stiffness of OA. 26 It is the relief of some of these clinical manifestations that accounts for the widespread use of NSAIDs not only in the United States, but around the world.
SOURCES: Byron Cryer, MD, spokesman, American Gastroenterological Association; associate professor of medicine, University of Texas Southwestern Medical Center, Dallas. Nieca Goldberg, MD, spokeswoman for the American Heart Association; chief of women's cardiac care, Lennox Hill Hospital, New York; author, Women Are Not Small Men: Lifesaving Strategies For Preventing And Healing Heart Disease In Women . John Klippel, MD, president and CEO, Arthritis Foundation, Atlanta. Scott Zashin, clinical assistant professor, University of Texas Southwestern Medical Center; author of Arthritis Without Pain . American College of Rheumatology web site. Arthritis Foundation web site. American Heart Association web site. American College of Gastroenterology web site. American Gastroenterological Association web site. American Academy of Family Physicians web site. American Academy of Allergy, Asthma, and Immunology web site.