Nonsteroidal anti-inflammatory drugs (NSAIDs) are available over-the-counter without a prescription. Included in this category are aspirin (Bayer), ibuprofen (Advil, Motrin), ketoprofen (Orudis KT), and naproxen sodium (Aleve). These medications relieve pain by reducing the production of prostaglandins, which are hormone-like substances that causes pain and inflammation. Therefore, NSAIDs can be extremely effective at reducing inflammation and calming swelling and irritation. NSAIDs are most beneficial in cases of acute pain, or flare-ups in patients with chronic pain. In general these should not be used on a daily basis for the treatment of chronic pain. When used on a daily basis for a period of several years, there is a risk of damage to the kidneys that can be significant. Furthermore, there is a well-known risk of gastric ulcer formation with NSAIDs. While the newer, COX-2 inhibitors (Celebrex, Vioxx), were designed to avoid this complication, caution should still be used if there is a risk of ulcers or GI bleeding.