Arthritis and NSAIDs. Illustration of an arthritic knee in front of a diagram showing how non-ster- oidal anti-inflammatory drugs (NSAIDs) are thought to work. The bones in this joint have lost their smooth surface and become pitted and rough. Arth- ritis is inflammation of a joint, characterised by pain, swelling, stiffness, and deterioration of joint tissues. NSAIDs, such as aspirin and ibupro- fen, are thought to help relieve the painful symptoms of arthritis by inhibiting the production of prostaglandin in the joint. Prostaglandin trig- gers inflammation and transmission of pain signals to the brain. The rows of blue spheres represent the cell membrane, where NSAIDs act.