The FDA reported Wednesday that the occurrence of atrial fibrillation was rare in patients treated with a bisphosphonate drug, used primarily to increase bone mass and reduce the risk for fracture in patients with osteoporosis, slow bone turnover in patients with Paget’s disease of the bone and to treat bone metastases and lower elevated levels of blood calcium in patients with cancer.
The agency said it reviewed data on 19,687 bisphosphonate-treated patients and 18,358 placebo-treated patients who were followed for six months to three years. The occurrence of atrial fibrillation was rare within each study, with most studies containing two or fewer events.
Across all studies, the FDA said that they did not observe a clear association between overall bisphosphonate exposure and the rate of serious or non-serious atrial fibrillation. Also, they found that increasing dose or duration of bisphosphonate therapy was not associated with an increase rate of atrial fibrillation.
An article and an accompanying editorial in May 2007 issue of the New England Journal of Medicine described increased rates of serious atrial fibrillation in two different studies of women ages 65 to 89 years old with osteoporosis treated with the bisphosphonates, Reclast and Fosamax. Data available to the FDA at that time, including data from the new drug approval (NDA) approval of Reclast for osteoporosis, showed an increased risk of serious atrial fibrillation and this risk was reflected in the Reclast labeling.
After its review, based on the data available at this time, the FDA is recommending that healthcare professionals should not alter their prescribing patterns for bisphosphonates and patients should not stop taking their bisphosphonate medication.