Trade Names: Arthrum, Synvisc

Synonyms: Viscosupplements, hyaluronic acid

Drug Class: Viscosupplement

Arthrum 2ml (bacterial)
Synvisc 2 ml (avian)
Synvisc-One 6 ml (avian)

Dose (for OA of the knee)
Arthrum 2ml (20 mg) intra-articular injection once weekly for 3 weeks
Synvisc 2ml (16 mg)  intra-articular injection once weekly  for 3 weeks
Synvisc-One 6ml (48 mg)  intra-articular injection once

Indications: Osteoarthritis of the knee

Mechanism of Action: Unknown; initially thought to improve viscosity of synovial fluid but because the duration of clinical effects can far exceed the time the drug is present in the joint, other mechanisms of action are likely.

Contraindications: Hypersensitivity to hyaluronate or any component of the formulation (some preparations avian source, some bacterial)

Precautions: Strict aseptic technique, do not inject extra-articularly

Pregnancy Risk: Unknown

Adverse Effects
Common: Pain and swelling in the injected knee
Less common: Rash, flushing, hypersensitivity

Comments: Most trials have found efficacy greater than placebo but quality of trials has been poor with true double-blinding difficult due to the viscosity of the injection. Controversial whether there is a clinically relevant effect. Injection reactions in the treated knee are usually minor but can resemble septic arthritis.

Adapted from: RheumaKnowledgy