Fluid retention with Aredia treatments

My mother-in-law is receiving Aredia by 2-hr. infusion every 3 weeks since last fall, and it helps her tremendously with bone pain. She takes Aromacin also but we are not sure yet if she will have another remission.  Just several days ago we noticed her belly getting larger and her face fuller, but her ankles aren't swollen (but she spends a lot of time resting on the couch.)  Will she be able to continue the Aredia with fluid retention?  Should we watch her ankles closely?  Does this mean her kidneys are starting to be affected?  She is 84 but has a very strong constitution and has had 3 remissions since 1982. We hate to worry her if this is a common side effect and nothing to be worried about.  She knows that without the Aredia she would be in great pain.   Thank you!

[CCF-RN,MSN-JS]

Dear Susanne, There could be a variety of causes for fluid retention.  Whether the Aredia should be discontinued would depend on what is thought to be the cause of the fluid.  Her oncologist should be able to give some insight as to what they consider the cause for the fluid retention, evaluation would begin with a physical exam and some general blood tests looking at kidney and liver function.