Warner Chilcott Plc (WCRX), Roche Holding AG (ROG), Merck & Co. and Novartis AG (NOVN) need to change the labeling of Bisphosphonates, a medicine taken by patients to prevent and cure osteoporosis, the FDA said.

The label should come with a clarification on the duration of taking the medicine. However, the FDA advisory committee could not agree on the time limit to be given on the labeling citing absence of sufficient data to identify the ideal time limit of the medication.

The FDA has been evaluating the safety of the medicine for last four years and found possible co-relation between long-term use of the medicine and atypical thigh bone fracture and jawbone deterioration in 2010.

Post-menopausal women affected with osteoporosis are often found to be taking these medicines and a study showed a possible connection between the long term medication and increasing rate of esophageal cancer risks. A study done in 2009 used the data from FDA's Adverse Event Reporting System and established a relation between the medicine and esophageal cancer. The research was published in the New England Journal of Medicine.

An estimation of 9 percent taking this medicine for more than three years and almost 1 percent taking them for more than five years is without knowing the consequences of the drugs is troubling, the FDA believes.

According to the panel, the revised label of the bisphosphonates should “be very clear that efficacy may fall off after a period of time, perhaps five years.” After the 17-6 vote on labeling clarification that took place in Adelphi, Maryland, panelist Lewis Nelson, director of the medical toxicology fellowship program at New York University, said “serious concerns have been raised about risk, and those need to be continually evaluated as well.”

In its own study done on the women who have been taking the medicine for over five years, the FDA concluded that no firm result on benefit or harm or evidence of clear and consistent reduced fracture risk have been found, Theresa Kehoe, MD and FDA scientist, told the panel. The safety and effectiveness data mentioned in the label is based on the data the companies gathered in one to four years research, he added. Therefore, a detailed study on the effect of the drug on long-term users’ health is a must.

Bisphosphonates medicines include Aclasta, Actonel, Altevia, Boniva, Fosamax, and Reclast.