What is Synvisc?
It is a sterile, apyrogenic, viscoelastic solution containing hylans or hyaluronic acid (HA) derivatives for the treatment of knee pain and joint inflammation associated with osteoarthritis (OA). It contains both Hylan A and Hylan B in buffered physiological sodium chloride. Synvisc is only approved FDA for intra-articular injection of the knee. It is being used off-label for other OA-affected joints such as the hips, ankles, and shoulders.
Composition and Characteristics
The active ingredients of Synvisc, Hylan A and B, are made from a type of hyaluronan that is extracted from rooster combs. This naturally occurring substance is also found in large amounts in the human body, particularly in joints, where it acts as a lubricant and shock absorber to help the joints function properly. Hylans are absorbed by the body through the same pathway that degrades hyaluronan. The metabolites produced from Hylan degradation are non-toxic.
Usage of Synvisc
- As a temporary replacement or supplementation for synovial fluid
- For patients in all stages of joint pathology
- For patients who are actively using the affected joint
- For intra-articular injection by a licensed physician treating pain due to osteoarthritis
- For patients who fail to experience adequate symptom relief from non-pharmacologic therapies and basic analgesics
- The drug should not be used in infected or inflamed joints or patients with active infection or skin lesions at the injection site.
- This should not be used if significant effusion is present in the affected joint.
- It is contraindicated in pregnant and lactating women, as well as children below 18 years of age.
- Synvisc should not be administered if venous or lymphatic stasis is observed in the affected limb.
The treatment plan for knee osteoarthritis is 3 injections in the knee with a 1-week interval. At least 3 injections are required to achieve maximum effect. The maximum recommended dosage is 6 injections within 6 months, with at least a 1-month interval between each session.
Most of the adverse events affecting the injected joint are mild and transient, but the possibility of serious side effects and complications must also be considered. Intra-articular infection did not occur in clinical trials, but a few cases have been reported during clinical use.
Common Post-Injection Reactions
- Pain or tenderness
Possible Side Effects and Complications
- Hypersensitivity reactions: anaphylactic shock, anaphylactic reaction, and angioedema
- Rare systemic events: itching, rash or hives, dizziness, headache, chills, muscle cramps, malaise, flushing, respiratory difficulties, nausea, paresthesia, peripheral oedema, and facial swelling