Essentially, the answer to your question appears to be that zero
percent of Zometa sales are for treatment of osteoporosis.
Zometa, an injectable drug, is approved for bone disorders associated
with some cancers.
There is experimental evidence that Zometa may also be effective in
treating osteoporosis. But from what I see, the drug is not yet
approved or marketed for use as treatement for osteoporosis.
For instance, this article from 2002 discusses Zometa's potential use
Researchers Investigate Once-Yearly Treatment for Osteoporosis as
Alternative to Daily Medication
Note that the articles states: "If large clinical trials confirm its
effectiveness, the manufacturer of Zometa may file for U.S. Food and
Drug Administration approval in 2005..."
I searched the FDA site for information on Zometa, as well as a
general Google search, but found no indication that the drug has been
approved for osteoporosis use.
In fact, this very recent article:
Cancer drugs may lead to debilitating bone condition
points out that there may be a serious category of side-effects
associated with bisphosphonates, the class of drugs that includes
The article also notes that osteoporosis patients take bisphosphonates
in pill form, whereas Zometa is an injected drug.
I trust this information fully answers your question.
However, if there's anything else you need, just let me know, and I'm
at your service.