[Pharmacological therapies for osteoarthritis].

According to international recommendations, acetaminophen should be used as a first-line therapy in patients with osteoarthritis, because of its safety and effectiveness. NSAIDs should be considered in patients unresponsive to acetaminophen, and should be prescribed at the lowest effective dose and for the shortest duration. The use of stronger analgesics, such as weak opioids and narcotic analgesics, is only indicated when other drugs, such as NSAIDs, have been ineffective or are contraindicated. Symptomatic slow acting drugs (avocado soybean unsaponifiable, chondroitin sulphate, diacerein, glucosamine sulphate, hyaluronan injections) have mild symptomatic effects and may reduce the consumption of NSAIDs. Intra-articular injections of glucocorticoids are indicated for flare of knee pain, especially if accompanied by effusion.