Description

There is some controversy regarding the effectiveness of polysulfated glycosaminoglycan. Once thought to increase collagen and glycosaminoglycan synthesis in cartilage culltures from normal and osteoarthritic horses, recent research shows it to have little effect.

Normal joints have pads of cartilage protecting the ends of the bones, composed of a surrounding capsule lined by a synovial membrane. Among the functions of the membrane is the production of lubricating joint fluid that reduces friction and wear on joint surfaces.

Polysulfated glycosaminoglycan is similar to this natural fluid, which consists of organic chemicals made up of protein and carbohydrate molecules.

Follow-up studies done at Colorado State University Equine Orthopaedic Research Center show that PSGAG, or Adequan, could prevent defects in cartilage, but could not heal a defect that was already there. "Although we know it does not heal defects left in the joint, it does decrease the rate of further cartilage degradation that probably ensues in most joints."

Usage

Polysulfated glycosaminoglycan is used to treat joint problems in equines and also has an ophthalmic use for experimental management of corneal ulcers.

Commonly, joint injury begins a cycle of inflammation, cartilage damage, and poor quality joint fluid that may lead to irreversible degeneration and degenerative joint disease. Polysulfated glycosaminoglycan is thought to protect cartilage by inhibiting enzymes that break down cartilage and by decreasing inflammation.

The drug is distributed throughout the body after intramuscular administration. It travels quickly through tissues and joints, with the highest levels occurring in inflamed joints.

Dosage and Administration

Polysulfated Glycosaminoglycan
Method	Dosage (click row for calculator)	Concentration	Period	Duration
Intramuscular injection	500 mg	100 mg/ml	Every 4 days	28 days
Intra-articular injection	250 mg	250 mg/ml	Weekly	5 weeks
Ophthahlmic	1-2 drops	5% PSAG1	Every 8 hours	NA
Notes: 1Veterinary approved Adequan may be diluted 1:1 with sterile artifical tears to produce a 5% PSGAG solution. Federal law restricts this drug to use by or on the order of a licensed veterinarian. Extra-label use of drugs in treating animals is allowable only by licensed veterinarians within the context of a valid veterinarian-client-patient relationship, and does not include drug use in treating animals by the layman (except under the supervision of a licensed veterinarian). The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your equine appears to feel better, the entire treatment plan should be completed to prevent relapse. This medication may be available in forms and concentrations not noted in the above table. Always check the label and literature provided with the medication about the form and concentration and DO NOT USE the calculator if the information differs. Calculator is for educational purposes only. Follow your veterinarian's instructions regarding use of this, or any medication.

Side Effects

Side effects from IM injection are rare. The most common side effect is pain at the injection site.

Occasionally, joint injections of PSGAG cause an acute inflammatory reaction in the joint. As a precaution, many veterinarians add antibiotics to PSGAG when injecting the joint.

Precautions

Polysulfated glycosminoglycan should not be used in infected joints.

Polysulfated glycosminoglycan is FDA-approved for use in horses and is a prescription drug. Federal law restricts this drug to use by or on the lawful written or oral order of a licensed veterinarian.

PSGAG is commonly used in competition horses. It is forbidden in drug-free competitions, and the individual regulatory group should be consulted for full information.

Interactions

PSGAG is closely related to heparin. It should be used with caution in animals that are being treated with anticoagulants.

Overdose

No adverse effects are noted in manufacturer's literature.