Q. My mum is currently on medication for her high blood pressure. In the meantime, a polyclinic physician had indicated that she should take glucosamine to treat her osteoarthritis.

She was advised to consume at least 1,500mg on a daily basis. A month ago, I gave her a bottle of glucosamine (1,000mg) to try out.

She has since developed rashes all over her hands and legs. She has been prescribed some medication for her rashes and itchiness.

She has now stopped taking the glucosamine.

What is the long-term solution for the osteoarthritis to be eased, but without getting rashes or itchiness?

A. Glucosamine has been used for the treatment of osteoarthritis and there are many clinical trials which show that oral glucosamine is effective in decreasing pain, improving function and in some cases even improving the X-ray appearance of arthritic joints.

The most common source of glucosamine is from the shell of shellfish; there are also vegetarian sources of glucosamine. Your mother may be having an allergic reaction to the glucosamine tablets.

This may be due to seafood allergens (although it is the shell of the shellfish and not the meat itself that is used for the production of glucosamine), or she may be allergic to the sulphur component found in the tablet.

Your options are to try non-seafood glucosamine such as vegetarian glucosamine, or non-sulphated glucosamine such as glucosamine hydrochoride or acetyl-glucosamine.

These details should be found on the label on the bottle.

- DR LIM LIAN ARN, CONSULTANT ORTHOPAEDIC SURGEON, RAFFLES HOSPITAL