Side Effects of Bisphosphonates Increase Risk of Atrial Fibrillation: Study

Researchers from the U.S. say that potential side effects of Fosamax and other oral bisphosphonate bone drugs could increase the risk of users suffering atrial fibrillation.  

In a study published in the October issue of the medical journal Chest, researchers indicate that evidence suggests that people who take a class of drugs known as bisphosphonates are at increased risk of heart problems, but do not appear to be at increased risk of death. The study also shows that the drugs do not increase the risk of stroke.

Researchers looked at six observational studies and six randomized controlled trials (RCTs) on the use of bisphosphonates from 1966 to 2012, with data on just under 150,000 patients involved. According to the findings of the observational studies, bisphosphonate users face a 27% increased chance of suffering atrial fibrillation. However, an analysis of the RCTs revealed a 40% increased risk.

The study also looked at whether there was an increased risk of stroke for bisphosphonate users, but none was found in the data.

Fosamax (alendronate sodium) is the most widely used bisphosphonate medication. It was introduced by Merck in 1995, for treatment and prevention of osteoporosis.  Before it became available as a generic in 2008, the medication generated over $3 billion in annual sales and was used by millions of Americans. Other medications that are part of the same family include Actonel and Boniva.

Fosamax Failure to Warn Lawsuits

While Fosamax is designed to strengthen bones and reduce the risk of fractures associated with osteoporosis, long-term use of the medication has been linked to an increased risk of low-trauma bone fractures, where the femur may completely break after little or no trauma at all.

In October 2010, following an investigation by the FDA, Merck was required to add new warnings about the risk of bone fractures from Fosamax and other bisphosphonates.  These warnings provided new information for consumers and the medical community about the importance of identifying symptoms of new hip or groin pain, which could occur before an atypical fracture of the femur.

Merck now faces about 1,000 Fosamax femur fracture lawsuits in state and federal courts throughout the country, alleging that the drug maker failed to provide adequate warnings about the risks associated with long-term use of the medications.

The lawsuits have been centralized before U.S. District Judge John Keenan in the Southern District of New York since 2006, to reduce duplicative discovery, avoid conflicting pretrial rulings and to serve the convenience of witnesses, parties and the courts.