Subtrochanteric Fracture Reports Coincident With Risedronate Use
Category: Osteoporosis - Treatment (Clinical)
Poster Sessions, Presentation Number: MO0353
Session: Poster Session III
Monday, September 14, 2009 12:00 AM - 12:00 AM, Colorado Convention Center, Exhibit Hall F
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Subtrochanteric fractures occur in postmenopausal osteoporosis although they are much less common than femoral neck or intertrochanteric hip fractures in the US. The subtrochanteric region of the femur consists primarily of cortical bone and therefore it is thought to be an uncommon place for a low-energy fracture. In the general population, subtrochanteric fractures account for approximately 4 - 6% of all hip fractures or less than 25 per 100,000 patients1.
There are several case reports in the literature of patients treated with alendronate and who presented with low energy subtrochanteric or diaphyseal stress fractures. Duration of exposure in these case series vary.
Risedronate has been studied in placebo-controlled Phase III osteoporosis trials of up to three years duration in over 15,000 patients and in active control studies involving nearly 4000 additional patients. The average duration of risedronate use in these trials was 1.9 years. In these studies, fractures were coded using a numerical system corresponding to specific anatomic locations.
In the active controlled studies with higher doses and extended intervals (35 mg once weekly, 75 mg on 2 consecutive days a month, and 150 mg once a month), no subtrochanteric fractures were reported. The incidence of hip or femur fractures was similar to those in the placebo-controlled studies.
In post-approval surveillance from May 1998 to September 30, 2008 with more than 18 million patient years of risedronate exposure, the reporting rate of subtrochanteric fractures is very rare (per CIOMS) or less than 0.1 per 100,000 patient treatment years of exposure, without attribution of causation. These are reports without x-rays so it is hard to determine if these are traumatic fractures or have the described x-ray appearance of these low energy atypical fractures.
These data do not support a causal relationship or an association between the use of risedronate and low energy subtrochanteric or diaphyseal fractures.
1Nieves et al in press
S. Silverman, Procter & Gamble Pharmaceuticals: Consulting fees or other remuneration (payment). , Procter & Gamble Pharmaceuticals: Employment (full or part-time). J. Bilezikian, Procter & Gamble Pharmaceuticals: Consulting fees or other remuneration (payment). A. Klemes, Procter & Gamble Pharmaceuticals: Employment (full or part-time). , Procter & Gamble Pharmaceuticals: Employment (full or part-time). F. Cosman, Procter & Gamble Pharmaceuticals: Consulting fees or other remuneration (payment).
* Presenting Authors(s):
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