Osteoporosis Drugs: Risk to the Heart?
Fosamax, Other Bisphosphonate Drugs Studied; No Reason to Stop Use, Experts Say
Real Risk or Fluke?
WebMD asked two independent experts to review Heckbert's study.
"The evidence here is interesting, but I'm not going to put this at a
high level of confidence at this point," Edward Puzas, MD, tells WebMD.
Puzas is a professor of orthopaedics, director of the Osteoporosis Center, and
director of orthopaedic research at the University of Rochester School of
Medicine in Rochester, N.Y.
"I think you're going to see articles coming out on both sides of this
right now, and my prediction is that in the end, it's going to sort itself out
that there's little if any risk associated with cardiovascular issues and these
bisphosphonates," Puzas says.
"I'm not ready to believe that the bisphosphonates, certainly as a
class, have got any real potential serious adverse event with regard to atrial
fibrillation," Puzas says. "Sometimes, where there's smoke there's
fire, but many times, when you retrospectively ... look at these articles, they
really do amount to statistical fluke or a statistical fluctuation, and it's
not until other people demonstrate them in other trials in a more prospective,
rigorous fashion that you can actually believe the evidence.
"If I were treating a new patient and about to put them on a
bisphosphonate, I would evaluate their cardiac status with an extra eye toward
looking at atrial fibrillation," says Puzas, adding that he wouldn't rule
out bisphosphonates based only on cardiovascular risk factors.
Henrik Toft Sorensen, MD, PhD, who worked on the Danish study published by
BMJ (formerly called the British Medical Journal) in April 2008,
notes that Heckbert's data "might be vulnerable" to factors not weighed
by the researchers. "This study does not change my recommendations for
treatment. More data are needed," Sorensen tells WebMD by email.
An editorial published in the Archives of Internal Medicine praises
Heckbert's study. But like Heckbert, Puzas, Sorensen, and the FDA, the
editorialists don't jump to conclusions about bisphosphonates and atrial
Drug Companies Respond
WebMD contacted Merck, the drug
company that makes Fosamax, for its response to Heckbert's study.
In a statement emailed to WebMD,
Merck notes that randomized clinical trials are "the gold
standard" for evaluating drug safety and efficacy, and Heckbert's
study was an observational study, not a randomized clinical trial. "We
strongly recommend that if patients have concerns about Fosamax that they talk
to their physician," states Merck, adding that "it's worth pointing out
that authors of the editorial in the Archives of Internal Medicine
conclude: 'At this time, it seems that the benefits of bisphosphonate
treatment in patients with osteoporosis outweigh the risks of [atrial
Reclast is made by the drug company Novartis. In May 2007, when The New
England Journal of Medicine published the results of the Novartis-sponsored
Reclast clinical trial, Novartis issued a news release stating that though 1.3%
of the Reclast patients in the trial developed atrial fibrillation, compared to
0.5% of those taking placebo, those findings didn't appear in other studies.
Novartis also noted that Reclast's active ingredient, zoledronic acid, has been
used by more than 1.5 million cancer patients, with no sign of increased risk of