Joint Supplementation: What To Do With Adequan Off The Market?

By James Bryant, DVM, Diplomate ACVS, Pilchuck Veterinary Hospital

8/6/13 UPDATE!: The pharmaceutical company that manufactures Adequan now anticipates release of Adequan products to the market beginning in late August 2013. More info:

Joint health is vital to the success of our athletic horses. There are a variety of products available to enhance the environment of the joint and allow for optimal function. Some products have good science behind them, others have anecdotal claims.

As a horse owner, the struggle has been to discern which products to use and what to expect from your investment. As veterinarians, we see the supplement market as having some beneficial products, but face the same dilemma: Which ones, and by which route (i.e., oral vs. injectable), are most effective?

Below is a breakdown of supplement classes, followed by a discussion of alternatives to Adequan while it is unavailable.

  • Sodium hyaluronate (hyaluronic acid): HA, as many people refer to it, is the lubricating substance of the joint. HA provides viscosity to the joint, allowing the cartilage to act as a shock absorber. HA also has anti-inflammatory properties when in normal concentrations in the joint. Common routes of administration are IV (Legend), intra-articular (HA with steroids in joint) and oral. Oral products have limited scientific research to support their efficacy; however, anecdotal information does exist. Legend has proven scientifically to be of benefit by both reaching the joint after administration and providing reduction in inflammation and increasing the production of endogenous HA.
  • Glucosamine/chondroitin: I have combined these two as they are used commonly together in supplements and interchangeably in lay literature. Simply put, these compounds are the building blocks of cartilage. They are essential for normal cartilage function and the depth of the cartilage layer, and have short-term but very potent anti-inflammatory effects after intra-articular administration. Routes of administration include oral, intra-muscular (IM) and intra-articular (IA, in the joint). There have been scientific results showing the benefits of IM and IA treatment. Oral supplementation scientifically has had mixed results in studies; however, clinically, some horse do appear to respond well. Examples of injectable products in this category include Adequan, Pentosan, PentAussie and a hybrid called Polyglycan.

As many of you know, Adequan is not available currently. Estimates by the company indicate that we are unlikely to see the product before the first part of 2014. Adequan is a product that I believe has benefit to the athletic horse; therefore, with the shortage, it is important to make the choice of a suitable alternative.

Pentosan is an Australian product. Like Adequan, it is a polyglycosaminoglycan or PGA (different sugars in the chemistry). In scientific literature, Pentosan has performed equal to or better than Adequan and, in my mind, is a suitable substitute. PentAussie (a U.S. version of Pentosan) and Polyglycan (a combination of HA and PGAs) are licensed only as a medical device given into the joint during arthroscopic surgery, and are not licensed for use as an IM (PentAussie) or IV (Polyglycan) product, though they are used this way. Pentosan is available in the U.S. on a conditional FDA license and, at this time, is my substitute of choice for Adequan.

As always, please discuss these options with your veterinarian and together choose products that are the best fit for your horse’s use and medical history.

For equine care and 24/7 emergency, call PVH at 360.568.3111.