Fosamax Linked To Heart Irregularity

A new study reports that the osteoporosis drug Fosamax may be linked to a doubling of a woman's risk of developing atrial fibrillation, according to researchers at the University of Washington.

Atrial fibrillation (AF) is a chronic irregular heart beat that can cause dizziness and fainting as well as fatigue. In rare cases it can lead to a blood clots and stroke.

Millions of women take Fosamax, the only osteoporosis drug that promises to build bone in postmenopausal woman. It's also shown to reduce hip fractures by 63 percent.

Researcher Susan Heckbert, a cardiovascular epidemiologist, decided to explore the risk after the “Horizon” report last year found the heart irregularity resulted from another drug in the same class, Reclast.

Reclast is given intravenously once a year, while Fosamax is a pill taken once a week.

In the University of Washington study, 719 women with AF were compared to 966 controls who were roughly the same age with the same blood pressure.  

Those on Fosamax (alendronate) were found to have an 86% higher risk of newly detected AF compared to those not on the drug.

Heckbert also analyzed a study from 1997 called Fracture Intervention Trial (FIT). It found, though inconclusive, that the Fosamax patients were more likely to have severe AF than those on the placebo.

A study last year in the New England Journal of Medicine found a slight risk of AF and a British Medical Journal study published this year found no increased risk of AF in women taking bisphosphonates, the class of drugs given to fight osteoporosis.

Merck & Co. Inc., the maker of Fosamax, says the link to antrial fibrillation from FIT or any other of the 28 trials involving Fosamax was "unlikely".

This news puts women in a bind but lead researcher Susan Heckbert says women should talk to their doctors before stopping the drug because, "the drug's benefit will vastly outweigh the risk of atrial fibrillation."

The study is published in the Archives of Internal Medicine. 

Osteoporosis happens when the bone building process within our body reverses itself after the age of 35. Then we breakdown more bone than we build leading to overall decline in bone mass. The quality and quantity of bone in adults is established by diet and exercise by the age of 18 in girls and 20 in boys.

The National Osteoporosis Foundation reports that by the year 2020, up to half of the women over the age of 50 will have osteoporosis as well as about 30 percent of men.  #