Now drug manufacturers have come up with several others in the same drug family. These include risedronate (Actonel), ibandronate (Boniva), and pamidronate (Aredia). Still being investigated is zolendronate (Zometa), which can be given in a single intravenous dose once a year.

One study that compared these drugs for a year in postmenopausal osteoporosis showed that Fosamax increased bone mineral density slightly more than the others. But the difference wasn't enough to suggest everyone should switch from one to the other.

There is much work to be done to sort out the answer to your question. These drugs may improve bone density, but do they reduce the risk of fracture? And which one works best for that? More study is needed to find out.

Researchers are also looking at the effects on bone density and fracture rates. Postmenopausal women who take a combination of drugs and supplements for their osteoporosis are often the main target of the research. There's a need to study the effect of bisphosponates on men as well.