PSGAG

What is PSGAG?

Polysulfated glycosaminoglycan (PSGAG) is a semi-synthetic drug primarily used in veterinary medicine, particularly for dogs and horses, to treat non-infectious degenerative and/or traumatic arthritis, also known as osteoarthritis. It is a chondroprotective agent, meaning it helps to protect and support cartilage.

Different Names/Synonyms:

• Adequan (a common brand name)

• Glycosaminoglycan polysulfate

• Sulfated glycosaminoglycan

PSGAG is derived from the tracheal cartilage of cows. It is structurally similar to the glycosaminoglycans (GAGs) that are naturally found in healthy cartilage. When administered, it is believed to help restore and maintain the health of synovial joints.

How It Works (Benefits)

The exact mechanism of action is not fully understood, but in vitro studies suggest several beneficial effects:

• Inhibits cartilage degradation: PSGAG is a proteolytic enzyme inhibitor. It may inhibit enzymes (like matrix metalloproteinases) that break down cartilage and bone.

• Stimulates cartilage repair: It is thought to stimulate the synthesis of key components of cartilage, including proteoglycans, collagen, and hyaluronic acid.

• Anti-inflammatory effects: PSGAG can help reduce inflammation and pain by inhibiting inflammatory mediators like prostaglandin E2.

• Improves joint lubrication: By stimulating the synthesis of hyaluronic acid, it can improve the viscosity and lubricating properties of synovial fluid.

• Protects cartilage: It helps to slow the progression of arthritis by protecting the existing cartilage matrix.

Side Effects and Risks

While generally considered safe, there are some known side effects and contraindications, especially in animals:

• Injection site reactions: Pain, swelling, or a hematoma (deep bruise) at the injection site are possible.

• Gastrointestinal issues: Transient diarrhea, vomiting, and anorexia have been reported.

• Bleeding risk: Because PSGAG is chemically similar to the anticoagulant heparin, it may increase the risk of bleeding. It should be used with caution in animals with known or suspected bleeding disorders, and when used concurrently with other anticoagulants or antiplatelet medications (like aspirin).

• Kidney or liver impairment: It should be used with caution in animals with pre-existing renal or hepatic impairment.

• Joint infection: In rare cases of intra-articular injection (directly into the joint), there is a risk of joint infection.

• Anabolic-Androgenic Ratio: There is no available information to suggest that PSGAG has any anabolic or androgenic properties. It is not an anabolic-androgenic steroid.

Dosage and Frequency

Dosage and frequency vary depending on the animal species and the specific product (Adequan Canine vs. Adequan I.M. for horses). Here are some general guidelines based on veterinary use:

• Dogs: The recommended dose is typically 2 mg/lb (4.4 mg/kg) of body weight, administered by intramuscular injection twice a week for up to 4 weeks (for a total of 8 injections).

• Horses (intramuscular): The recommended dose is 500 mg, administered every four days for a total of seven doses.

• Horses (intra-articular): The recommended dose is 250 mg once a week for five weeks.

The initial series of injections is followed by a re-evaluation, and the treatment may be repeated if clinical signs return.

Pharmacokinetics

• Half-life: Specific half-life values for PSGAG are not widely published for public consumption, but studies show it is rapidly absorbed and distributed. It reaches peak blood concentration within 20-40 minutes after intramuscular injection.

• Detection time: Detection times for PSGAG in athletic competitions are not available in public resources. However, it is important to note that it is considered a legitimate medication for treating joint disease in performance animals. Its presence in a drug test would be subject to the rules and regulations of the specific athletic governing body.

Steroidogenic, Progestronic, and Prolactin Effects

There is no scientific evidence to suggest that PSGAG has any steroidogenic, progestronic, or prolactin-related effects. It is not a hormone and does not function through these pathways. Its primary action is on the cartilage and synovial fluid within joints. In fact, some studies show a difference in how PSGAG and glucocorticoids (a type of steroid hormone) affect cartilage, suggesting they work through different mechanisms.