Tuesday, July 04, 2006

Biphosphonates and jaw osteonecrosis

My post about biphosphonates and osteonecrosis of the jaw (ONJ) drew an interesting comment from Liz, author of a blog devoted to the problem. Concerning my reference to a linked study showing that the major incidence of ONJ is with parenteral biphosphonates in patients with myeloma or metastatic bone disease she states: “That simply isn't true. Oral surgeons and dentists have been seeing patient after patient with jaw necrosis from Fosamax and other bisphosphonate drugs.” Wait a minute. Not so simply, please. According to the systematic review the oncology patients on parenteral therapy represent 94% of published cases despite much heavier use of oral biphosphonates such as Fosamax.

Yes, there are are many “real world” anecdotes about Fosamax, but in order to be convincing Liz should give us a denominator, which I suspect would be huge! Then and only then will we have any idea of the absolute risk for ONJ form oral biphosphonates.

1 comment:

Anonymous said...

Shouldn't the denominator be women who needed dental surgeries, not all women on Fosamax? Until recently Fosamax has been prescribed to 70-something women with osteoporosis. How many of these women still have many of their teeth left? Also, the probability of these women benefitting is pretty high as their risk of fracture is high.

But in recent years Fosamax has been aggressively marketed to relatively young women - those still in their 50s and even 40s with mild osteopenia and/or risk factors. These women are likely to stay on Fosamax for many many years. What if the risk increases with the length of time one is on Fosamax? Also, these women still have their teeth and the probability that they'll need extraction and implants or various types of periodontal surgery in future is very high. So there is a "what if it'll happen to me" fear which will precede any dental surgery for years to come. At the same time the probability of an individual woman with osteopenia benefitting is likely to be low. (What is the NNT for primary prevention with Fosamax for women in their 50s who do not yet have osteoporosis?).
Also, these particular side effect, although low, is extremely scary. It is painful, disfiguring and untreatable.