Oral bisphosphonates and incidence of BRONJ
The clinical efficacy of oral bisphosphonates for the treatment of osteopenia/osteoporosis is well
established and is reflected in the fact that over 190 million oral bisphosphonate prescriptions
have been dispensed worldwide. 47 The specialty’s experiences have identified several BRONJ
cases related to oral bisphosphonates. 24, 26 Patients under treatment with oral bisphosphonate
therapy are at a considerably lower risk for BRONJ than cancer patients treated with monthly IV
bisphosphonates. Based on data from the manufacturer of alendronate (Merck), the incidence of
BRONJ was calculated to be 0.7/100,000 person/years of exposure. 48 This was derived from the
number of reported (not confirmed) cases that were deemed to likely represent BRONJ divided
by the number of alendronate pills prescribed since approval of the drug, and converted to
number of patient years. While this is the best available data to date, there may be serious under-
4
reporting and, as noted above, none confirmed. Surveillance data from Australia estimated the
incidence of BRONJ for patients treated weekly with alendronate as 0.01-0.04%. 49 In a survey
study of over 13, 000 Kaiser-Permanente members, the prevalence of BRONJ in patients
receiving long-term oral bisphosphonate therapy was reported at 0.06% (1:1,700). 50 Felsenberg
reported a prevalence of BRONJ among patients treated with bisphosphonates for osteoporosis
of 0.00038%, based on reports of 3 cases to the German Central Registry of Necrosis of the
Jaw.