Natural Products

Glucosamine

Glucosamine sulfate

Efficacy

• Indications with proven efficacy:
  Mild to moderate osteoarthritis
• Also used for these other indications, but with no proof of efficacy:
  Ankylosing spondylitis
  Bursitis
  Gout
  Renal lithiasis
  Rheumatoid arthritis
  Tendinitis

Security

• Risk of Drug Interactions: Low
• Adverse Effects: Rare

What is it?

Glucosamine is a naturally-occurring molecule found in the human body. It is present in the synovial fluid which is responsible for joint lubrification. In some arthritic diseases, there is a lack of synovial fluid which causes pain, swelling and reduced joint mobility.

Several salts of glucosamine are commercially available, such as sulfate, hydrochloride and others. Since most studies have been performed on glucosamine sulfate, the efficacy of these other salts has not been established.

Commercially available glucosamine comes from natural sources, such as sea shells. Oral glucosamine is absorbed at a rate of about 90%.

Warning

In 2004, Canada adopted new regulations that control the manufacturing, packaging, labeling and importing of natural health products. The new regulations also include an adverse reaction reporting system. Products that conform to the regulation's criteria are identified with a natural product number (NPN) or homeopathic medicine number (DIN-HM) and can be legally sold in Canada. This number indicates that the product meets specific criteria for safety and purity, not that it is effective for any indication.

Medicinal plants content varies naturally from plant to plant – just as fruits from the same package may vary in taste and texture. There is no standard to measure the active content of each plant. Thus, efficacy of natural products should be expected to vary from brand to brand as well as from bottle to bottle of the same brand.

For more information about the Natural Health Products Regulations, or to check if a product has been assessed, visit the Health Canada website at http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index-eng.php.

Does it work?

The efficacy of glucosamine sulfate in the treatment of osteoarthritis has been compared to nonsteroidal anti-inflammatory agents (NSAIDs). Evidence suggest that the relief of osteoarthritis symptoms with glucosamine is similar or superior to NSAIDs. NSAIDs are faster acting, but the relief obtained with such agents rapidly disappear as soon as they are stopped.

• Mild to moderate osteoarthritis:
  Glucosamine sulfate appears effective in the treatment of osteoarthritis. The usual dose is 500 mg of glucosamine sulfate, orally, 3 times a day. Symptoms relief appear within 2 to 6 weeks and benefits may last for up to 3 years. However, its long-term safety and efficacy have not been established.

There is insufficient reliable information to conclude that glucosamine is effective in any other indication.

Is it safe?

• Glucosamine sulfate is not associated with any severe toxicity. In fact, it is generally very well tolerated and causes very few adverse effects. On occasion, people may suffer from nausea, heartburn, diarrhea or constipation. Glucosamine is associated with a much lower incidence of heartburn than NSAIDs. The safety of long term use has not been established. People with allergies to shellfish should use glucosamine with caution.
• Glucosamine does not appear to affect diabetes. Diabetic patients who wish to used it should however be cautious. Some glucose monitors may mistake glucosamine for glucose and give falsely elevated readings. Diabetes monitoring could be affected.
• Since there is no safety data available concerning its use during pregnancy and breast-feeding, pregnant and lactating women should not use glucosamine.
• Glucosamine may enhance the effects of oral anticoagulants, such as Coumadin.

Clinical notes

• Contrary to nonsteroidal anti-inflammatory drugs, which offer only temporary relief of the pain and inflammation associated with osteoarthritis, glucosamine appears to slow the progression of the disease. It has no direct analgesic effect. Glucosamine is often combined with chondroitin, however it is not known if such a combination is more beneficial than each drug taken alone. A possible synergy between these products remains to be established.

References

1. Pharmacist's Letter, CE Booklet: Nonherbal Dietary Supplements, Fall 1998
2. Natural Medicines Comprehensive Database, Therapeutic Research Faculty, 2007
3. Lininger S. et Al. The Natural Pharmacy, Prima Health, 1998
4. Passeportsanté.net. Glucosamine. http://www.passeportsante.net
5. Rotblatt M. et Ziment I. Evidence-Based Herbal Medicine, Hanley & Belfus, 2002
6. Haraoui B. et Ouellet M. La glucosamine dans le traitement de l'arthrose: efficace?, Le Clinicien, February 2003
7. Rinkor LJ. Can Glucosamine be Safely Used in Diabetes Patients? Pharmacist's letter, No. 190906 September 2003
8. Canadian adverse drug reaction newsletter, Vol. 11 No.2, April 2001
9. Kingston Richard L. Glucosamine Therapy: Shellfish Allergy a Problem? APha Drug Info Line, October 2003