Fosamax (alendronate) implicated in AF

SEATTLE, WASHINGTON. A recent (2007) clinical trial of once-a-year osteoporosis treatment with zoledronic acid (a bisphosphonate) revealed that this treatment significantly increased the risk of atrial fibrillation from 0.5% to 1.3%, or a 2.6-fold risk increase. The obvious question at the time was, “Do more common orally-administered bisphosphonates such as alendronate (Fosamax) also increase the risk of atrial fibrillation in postmenopausal women with osteoporosis?” Clinicians at the University of Washington in Seattle, the University of California, and the Center for Health Studies, Group Health also in Seattle now provide an answer to this question.

Their study involved 719 women with diagnosed afib and 966 matched controls who had been receiving health care at Group Health for a median of 20 years. The median age was 75 years for afib patients and 71 years for controls. The women were observed for a 6-month period during which 45.6% were diagnosed with persistent or recurrent paroxysmal AF – 41.6% experienced just one self-terminating episode and 11.5% were found to have permanent AF. Women who had ever used alendronate (irrespective of how long they had used it, or how much their cumulative intake had been) were found to have an average 86% greater relative risk of being diagnosed with afib. The risk of being diagnosed with permanent afib was almost 6 times greater among ever users of alendronate than among those never using it. The relative risk increase for women with persistent/recurring afib was 25% and for those with just one self-terminating episode the increase was 93%. Adjustment for possible confounding variables such as cardiovascular disease, BMI, cholesterol levels, estrogen therapy, osteoporosis, etc. did not change these risk estimates. However, the researchers did note that the combined use of alendronate and statin drugs was associated with a 13-times increased risk of developing AF.

The researchers conclude that 3% of the AF diagnoses made during the 6-month study can be attributed to alendronate use. They further state that the benefits of fracture prevention in high-risk patients will generally outweigh the possible risk of AF. However, in women with only modestly increased fracture risk the benefits may be less clear.

Heckbert, SR, et al. Use of alendronate and risk of incident atrial fibrillation in women. Archives of Internal Medicine, Vol. 168, No. 8, April 28, 2008, pp. 826-31

Editor’s comment: Alendronate (Fosamax) can also cause stomach ulcers, particularly in combination with naproxen and has been strongly implicated in rotting of the jawbone after dental work. Add a substantial risk of atrial fibrillation and it is clear that alendronate is by no means an innocuous drug. Fortunately, there are highly effective alternative means of preventing and treating osteoporosis. Lifestyle changes and supplementation with calcium, magnesium, strontium, boron, zinc and vitamins C, D and K can go a long way towards dealing effectively with osteopenia (the forerunner of osteoporosis) and osteoporosis itself. See Natural Approach