Oh, the irony. The very drugs prescribed to strengthen bones can spark stabbing limb and joint pain, according to a reminder from the FDA. Info about the possibility of those pains--which can be incapacitating in some people--is included in the labeling for the bisphosphonate drugs, sold under the brand names Fosamax (Merck); Actonel (Procter & Gamble); Boniva (Roche); and Zometa and Reclast (Novartis). But, fearing that the cautionary language goes overlooked, the agency wanted to highlight it. The FDA is reviewing the problems and expects to report back in six months.
It isn't the first whiff of trouble for these osteoporosis drugs. Fosamax users have sued Merck, alleging that the drug caused their jaw bones to decay, a condition known as osteonecrosis. And the FDA is investigating bisphosphonates to see whether they may cause atrial fibrillation, a heart rhythm disorder.
Still, bisphosphonates remain extremely popular, with some 10 million Americans taking them. The class leader, Fosamax, delivered $3.1 billion to Merck's top line in 2006. And when cheaper copycats of that drug reach market--a development expected later this year--even more patients may have access to them.