Osteo Express: Bisphosphonate Safety

After many years of ignoring important drug safety concerns, the Food and Drug Administration (FDA) is taking action. The agency recently alerted women about pos-sible problems with the most commonly used osteoporosis medicines, saying it needs more studies to explore how they might be damaging the hearts of people who take them. The drugs, bisphosphonates, are used by millions of women to strengthen their bones and lessen the risk of a serious fracture. NWHN supported bisphosphonates’ development to give women an alternative to long-term use of menopause hormone therapy, which was the most common osteoporosis treatment.

But when alendronate (Fosamax), the first bisphosphonate, and others got approved, we cautioned that the drugs’ long-term effects also needed to be carefully evaluated. For many years, we were disappointed and concerned that neither the manufacturers nor the FDA were looking into this. Now, things are starting to change, possibly because the NWHN and other consumer advocacy groups successfully advocated for Congress to enact a new law sending the FDA a strong signal that safety matters.

After two bisphosphonate studies showed problems with heart damage, the FDA examined the effect of these drugs on the heart and found that women taking zoledronic acid (Reclast) and alendronate were more likely to have dangerous irregular heart beats (atrial fibrillation). After examining the available data, the FDA wasn’t able to confirm the drugs cause the irregular heart rhythms, but can’t rule it out, either. The FDA says it will do further studies on the issue, but in the meantime it has alerted women about the possible problem.

The FDA advised women currently taking bisphosphonates not to stop. However, NWHN believes there may be many women taking the drugs for whom the benefits don’t outweigh the risks; we urge women and prescribers to carefully evaluate whether they should be on the drugs. Healthy, middle-aged women whose only reason for taking the drug is that a test showed some loss of bone density may decide they don’t want to increase their risk for heart problems to ward off a bone fracture that may or may not happen. (For more on the over-use of bone density screening tests, see NWHN’s Osteoporosis Fact Sheet.)

The FDA also announced it has put off the decision whether or not to approve the osteoporosis drug lasofoxifene (Fablyn) until it can look at the results of a five-year study. At an FDA Advisory Committee meeting in September, NWHN pointed out that Pfizer’s three-year study of the drug revealed several safety concerns, including life-threatening blood clots and an increased risk of hysterectomy. The Network asked the FDA not to approve the drug until there was more long-term safety data. The FDA has done what we asked them to do to protect women’s health, and a final decision is expected sometime in 2010. We sent this information directly to subscribers to NWHN's on-line Osteo Express. Don't wait for the latest news and analysis from NWHN: sign up for the Osteo Express and other e-alerts at www.nwhn.org.