Incidence of serious side effects with intravenous bisphosphonate: a clinical audit.

BACKGROUND Bisphosphonates (BP) have been associated with osteonecrosis of the jaw (ONJ) and atypical femoral fractures (AFF). The prevalence of these side effects in intravenous (IV) BP-treated subjects is not well understood. AIM This audit aimed to delineate the prevalence of ONJ, thigh pain and AFF in patients having regular IV BP and its effect on bone mineral density (BMD). Design and METHODS Patients attending for IV BP over a 3-month period completed a questionnaire about thigh pain and dental health. Data concerning BMD, treatment indication and treatment history were obtained from medical records. RESULTS There were 201 patients between 28 and 94 years (74.1% female) mostly on zoledronate (ZOL) (102) or pamidronate (PAM) (97). Osteoporosis (75.6%) and Paget's disease (16.5%) were the main indications for treatment; median length of IV BP was 4 years (range 0.25-25). One patient had ONJ (0.5%) while oral pain was reported by 6.5% and 12.7% noted tooth loosening. Twenty-seven subjects (13.4%) complained of current thigh pain. AFF occurred in four patients (2%), none of whom had idiopathic osteoporosis. At time of AFF, only one patient had a femoral neck T-score less than -2.5. All four had received pamidronate treatment; median 12.5 years (range 7-22). IV BP treatment significantly increased lumbar spine BMD but not femoral neck BMD. CONCLUSION Classical ONJ was rare (0.5%), although tooth loss was more frequent. Thigh pain was frequent while AFF occurred in 2.0% of subjects and was associated with long treatment periods and non-osteoporotic bone.