The best painkiller depends on the cause of the pain and its severity. The most common are over-the-counter pain relievers such as acetaminophen and non-steroidal anti-inflammatory medications, states Everyday Health. All of these medications have an analgesic effect, and NSAIDs such as aspirin, ibuprofen and naproxen also reduce inflammation.
Over-the-counter painkillers are useful for decreasing knee pain due to simple sprains as well as that caused by arthritis, explains Everyday Health. They must be used as per the given instructions and warnings, because overdose can cause side-effects such as liver damage and gastrointestinal problems. Glucosamine and chondroitin sulfate, which is an oral supplement, helps relieve knee pain caused by osteoarthritis.
Prescription medications that relieve knee pain include celecoxib and prescription-strength anti-inflammatory drugs, states Everyday Health. Injectable medications such as corticosteroids and hyaluronic acid, which reduce knee pain, are administered when pain is severe.