A major feature of multiple myeloma is thinning and weakening of the bones. Deposits of myeloma cells can make 'holes' in the bone, as the strengthening calcium is lost from areas of bone. This can be very painful and may even cause the bones to break with the minimum of trauma, or even spontaneously. As calcium is lost from the bone, the blood levels of calcium may rise. This may cause symptoms like nausea, vomiting, tiredness, irritability and confusion.

A group of drugs called bisphosphonates can help to reduce the loss of calcium from affected areas of bone, and may even be able to encourage more calcium to be laid down in bone. There are two bisphosphonates in common use at present: pamidronate (Aredia®), which is given by an intravenous drip over several hours as a day-patient every 3-4 weeks, or alternatively a tablet with similar properties called clodronate (Bonefos®) which may be given once or twice daily. A newer bisphosphonate called zoledronic acid (Zometa®) may also be used. This is given as an infusion over 15 minutes. We know from a number of studies that by taking one of these agents bone pain can be reduced, the risk of fractures is also reduced, thus quality of life may be improved.

Very recent studies have suggested that bisphosphonates may also have a direct anti myeloma effect, by both stimulating the immune system and damaging myeloma cells themselves.

When initially pamidronate was given to patients with myeloma, it was given for a period of 9 months. More recent studies have compared longer periods of time to shorter periods and it seems that the longer you give it the better. It now seems apparent that prolonging the time it is given for may continue to reduce the number of bone problems. So no one really knows at present how long it should continue. Some doctors now recommend giving it for 2 years, but others feel that it may be beneficial to continue as long as there is evidence that bones may be weak.