Long-term exposure to a class of osteoporosis drugs called bisphosphonates is associated with serious side effects, concluded panels to the Food and Drug Administration (FDA).

Moreover, data suggests that long-term exposure brings little or no incremental benefit in combating osteoporosis, according to the FDA.

Due to the possibility that bisphosphonates can cause these side effects , the panel is recommending that makers of bisphosphonates be required to clarify how many years patients should take their drugs for.

The FDA does not have to take its panels’ recommendations, but it usually does. Currently, bisphosphonates labels merely state that the “optimal duration of use has not been determined.”

Bisphosphonates – which includes Merck’s Fosmax and Roche’s Boniva – were introduced 16 years ago (Fosmax was the first one) and have proven “highly effective at decreasing the fracture risk associated with osteoporosis,” according to the FDA.

However, data does suggest that long-term use – defined in this case as more than 3 to 5 years – is associated with osteonecrosis of the jaw (ONJ), atypical subtrochanteric and femoral diaphyseal fractures, and esophageal cancer.

The FDA’s own report on bisphosphonates emphasized that the data only shows association with, but causing, serious side effects.

So while evidence of mere association is enough to raise concern, the FDA urged more studies – including ones that control for other factors that could cause the side effects – to advance knowledge on this matter.

Below is a list of bisphosphonates (courtesy of the FDA):

Medicine