What Is Euflexxa?

Euflexxa Injections Are Used in Viscosupplementation

Knee injection
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Euflexxa is a solution of highly purified hyaluronan (also called hyaluronic acid or sodium hyaluronate) in saline. The hyaluronan in Euflexxa is extracted from bacterial cells. It is the first non-avian derived hyaluronan.

Euflexxa is one of the hyaluronates used in viscosupplementation. Euflexxa is injected directly into the knee joint to restore the cushioning and lubricating properties of normal synovial fluid (i.e., joint fluid).

Knee joints affected by osteoarthritis lose their lubricating properties.

Indication for Euflexxa

Euflexxa was approved by the U.S. FDA on December 3, 2004 for the treatment of knee pain associated with osteoarthritis in patients who have failed to respond to more conservative non-drug therapy (e.g., physical therapy) and to simple analgesics, such as acetaminophen. Euflexxa is administered as a series of three weekly intra-articular injections.

Contraindications for Euflexxa

People with a known hypersensitivity to hyaluronan products should not be treated with Euflexxa. Also, people with an infection in the knee joint, other infection, or skin disease in the area where the injection would occur should not be treated with Euflexxa.

Common Side Effects and Adverse Events

The most common adverse events associated with Euflexxa treatment during clinical studies included arthralgia (joint pain), back pain, pain in the arms or legs, musculoskeletal pain, and joint swelling.

Adverse events that may occur with any intra-articular injection include arthralgia, joint swelling, joint effusion, injection site pain, and arthritis.

Precautions and Warnings

After receiving an intra-articular injection of Euflexxa, as with any joint injection, it is recommended that the patient avoid strenuous activities or prolonged weightbearing activities for 48 hours.

Also, it should be noted that pain or swelling may occur after the injection, but will diminish after a relatively short time period.

The safety and effectiveness of Euflexxa has not been established in pregnant women. It is not known if Euflexxa is excreted in human milk as the safety and effectiveness has not been established in lactating women. Also, safety and effectiveness of Euflexxa has not been established in children.

The Bottom Line

Other FDA-approved viscosupplements, along with the date they were approved, include:

The American Association of Orthopaedic Surgeons (AAOS) concluded, "Although some patients report relief of arthritis symptoms with viscosupplementation, the procedure has never been shown to reverse the arthritic process or re-grow cartilage. The effectiveness of viscosupplementation in treating arthritis is not clear. It has been proposed that viscosupplementation is most effective if the arthritis is in its early stages (mild to moderate), but more research is needed to support this.

Research in viscosupplementation and its long-term effects continues."


Viscosupplementation Treatment for Knee Arthritis. OrthoInfo (AAOS). Reviewed June 2015.

Euflexxa. Prescribing Information. RevisedĀ  June 2015.

Ferring Pharmaceuticals Announces Launch of Euflexxa For Osteoarthritis Knee Pain, News Release Ferring Pharmaceuticals Inc., November 14, 2005.

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