Jaw osteonecrosis and bisphosphonates for osteoporosis

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Jaw osteonecrosis and bisphosphonates for osteoporosis



May 16, 2006

Zosia Chustecka



Philadelphia, PA - A review of jaw osteonecrosis as a recently

described adverse effect of bisphosphonate therapy in the May 16,

2006 issue of the ls of Internal Medicine concludes that most

cases have developed in cancer patients being treated with

intravenous products but adds that cases have also been reported in

patients taking oral bisphosphonates for osteoporosis [1].



" The concern is that with more women aging and taking bisphosphonates

for longer periods of time, more cases of osteonecrosis may develop

even in patients receiving alendronate or ibandronate therapy. "



Written by Dr Sook-Bin Woo (Brigham and Women's Hospital, Boston, MA)

and colleagues from the University of Iowa and Ohio State University,

the article is a position paper of the American Academy of Oral and

Maxillofacial Pathology. The authors note that an increasing body of

literature about this side effect has built up over the past two

years, and in their paper they review 368 cases. They point out that

94% of patients with this adverse effect were taking intravenous

bisphosphonate products—primarily pamidronate (Aredia, Novartis) and

zoledronic acid (Zometa, Novartis)—and 83% of these patients had

multiple myeloma or metastatic breast cancer.

Only 4% of the cases reviewed (15 patients) were being treated for

osteoporosis. Of these, 13 patients had been taking alendronate

(Fosamax, Merck & Co); one patient took alendronate as well as

intravenous zoledronicacid and one patient took risedronate (Actonel,

Procter & Gamble). The authors point out that one patient had been

taking alendronate for only two years when the jaw osteonecrosis

occurred and comment: " The concern is that with more women aging and

taking bisphosphonates for longer periods of time, more cases of

osteonecrosis may develop even in patients receiving alendronate or

ibandronate therapy. " Ibandronate (Boniva, Roche), recently approved

for use in osteoporosis, is a potent nitrogen-containing

bisphosphonate, like alendronate, risedronate, zoledronic acid, and

pamidronate. However, while jaw osteonecrosis has been reported with

these other drugs, it hasn't as yet been reported with ibandronate,

and the risks associated with this product are unknown, the authors add.

" The degree of risk for osteonecrosis in patients taking oral

bisphosphonates, such as alendronate, for osteoporosis is uncertain

and warrants careful monitoring, " the review concludes. As previously

reported by rheumawire, in the US there is currently ongoing

litigation over jaw osteonecrosis occurring as a side effect of

bisphosphonate therapy, and a class action has been filed against

Merck for alendronate.



" The degree of risk for osteonecrosis in patients taking oral

bisphosphonates, such as alendronate, for osteoporosis is uncertain

and warrants careful monitoring. "



The authors also describe what to look out for with this adverse

effect. Clinically, intraoral lesions appear as areas of exposed

yellow-white, hard bone with smooth or ragged borders, they write.

Sinus tracts may be seen either in the mouth or around it (one

photographed case shows a sinus tract opening out under the chin).

There may also be painful ulcers in soft tissue that impinges on the

ragged bony margins.

More than half of all cases (60%) occur after dentoalveolar surgery,

such as tooth extraction, to treat infection, and the remaining 40%

of casers are probably related to infection, denture trauma, or other

physical trauma. Preventive strategies include removing all sites of

active and potential jaw infection before starting bisphosphonate

therapy to minimize the need for future oral surgery. Similar

protocols have already been established for patients preparing for

allogenic stem-cell transplantation and those about to receive

radiation to the head and neck, the authors point out.

Woo SB, Helstein JW, Kalmar JR. Systematic review: bisphosphonates

and osteonecrosis of the jaw. Ann Int Med 2006; 144:753-761.

http://www.jointandbone.org/viewArticle.do?primaryKey=698853