What a bind. Millions of older women taking a widely prescribed drug to prevent bone fractures face unsettling news that the popular Fosamax has shown an even higher link to certain heart risks than previously documented.

The disclosure appears to present women with another confounding case of "pick your poison" -- a medical regimen that is supposed to stop bone-thinning but also could lead to chronic irregular heartbeat. Even the main author of the latest study, from the University of Washington in Seattle, seemed conflicted. Dr. Susan Heckbert cautioned women taking Fosamax not to quit without consulting their doctors.

Fosamax reputedly is the only drug known to build bone in women prone to osteoporosis, and research has shown that it can reduce hip fractures by 63 percent. But it also may double a patient's odds of atrial fibrillation. This type of irregular heartbeat isn't necessarily a life-threatening condition but it can, in some cases, lead to a stroke.

As with many studies, more data is needed to determine conclusively whether the tie is real or coincidental. In the meantime, it's up to patients to use careful, individual and informed judgment when weighing the risks and benefits.