Dear Amelie,
I am not sure but I think Zometa is considered to be the best option. My husband Stephen swapped from Pamidronate to Zometa and now has it monthly since he had has SCT. He has to have his calcium levels checked before he has the zometa infusion in case it brings his calcium levels down too far, and as they are often on the low side he takes calcium tablets daily. There is now some evidence that Zometa helps to delay the progress of myeloma. I forget where I read the research but I do remember it was reported in a post on this website.
Steve has had troouble with allergies to drugs, he was allergic to allopurinol during his SCT but has had no trouble with zometa. I hope this helps,
Mari xx