Glycosaminoglycans (chondroitin sulfate injection)

[vetmedgirl]

Hi yall,

I am a 2nd year veterinary student and in pharmacology we have been talking about substances used in treating osteoarthritis.  There is a drug used called Adequan which comes as an injectable (IM) and contains  polysulfated glycosaminoglycans (mostly chondroitin sulfate).  While working at the vet clinic during the summers we used this "drug" quite a bit, usually in horses, and also in dogs with hip dysplasia.  It is supposed to promote synthesis of cartilage matrix components such as collagen, and inhibits catabolic enzymes (the enzymes that break down stuff) and a certain prostagland (PGE2-inflammation prostaglandin); therefore it is a chondroprotective that inhibits inflammation and degradation of articular cartilage and improves the viscosity of synovial fluid.  The usual routine for dogs is a 1cc injection in the muscle (hind limb) once or twice a week for four weeks then every other week.  This seems to work miracles in dogs for relief of pain anyways.  I've seen dogs that wouldn't even stand on hind limbs before and after about 3 weeks of treatment come running in jumping around and very happy.  I was wondering if there is a human equivalent to this.  I hear of people getting synvisc injections in the joint, I am assuming this is hyaluronic acid injections or something like that, but anything like this that is injected into muscle??  I was told that oral chondroitin is pretty much useless because the body can not absorb it.  Anyways hopefully I can get some info.

[OSDKnees]

I also work with horses.  The product you are talking about, Adequan, is a poly-sulfated glycosaminoglycan (PS-GAG) which is related to a family of other GAGs.  Hylaluronic Acid is a GAG.  The veterinary equivalent is Legend, which is an IA(into the joint capsule) or IV, and Hylartin V, which is an IA.  There are, of course, other "off-labels," but those are the only ones that are aproved by the FDA.

Anyway, the science with horses seems to be superior than humans when it comes to HA.  First of all, the two injectables for humans (Synvisc and Hyalgan) are both IA only.  Also, both are derived from roostercomb source, which leads to protein-contamination and the possiblity of allergic reactions.  Legend for horses comes from a sterile bio-fermentation process.

Also for horses, oral HA is the new big thing that seems to be far more advantageous to injections.  There is now oral HA supplements for people, but it hasn't caught on with MDs as it has with veterinarians.  I actually have to go to my vet to get my joint supplement!  I take one called Conquer III, which is made by the same company that developed the original oral HA for horses, Conquer.

Good luck in vet school!