Oral bisphosphonate adverse effects in 849 patients with metabolic bone diseases

Bisphosphonates are potent antiresorptive agents used for a spectrum of metabolic bone diseases. The aim of this study was to compare the adverse effects (AEs) of alendronate, etidronate and risedronate prescribed in a non-selected population, attending a single institution on an outpatient basis.

849 patients receiving either alendronate (n=710), etidronate (n=181) or risedronate (n=130) were studied for a period of 1916 person-years.

AEs were reported by 25.2% [21% gastrointestinal (GI) system-related], 11.1% (9.9%) and 20.8% (15.4%) of patients on alendronate/etidronate/risedronate, respectively, resulting in permanent discontinuation in 21.0%, 7.7% and 13.8%, respectively. The odds ratio (95% Ci) for AEs in the case of a history of gi disease was 2.4 (1.4-3.8), 2.1 (0.8-5.1) and 2.5 (0.9-6.6), respectively. The majority of AEs were of a mild nature and usually occurred within six months of therapy initiation. The odds ratio for AEs given the concurrent use of NSAIDS was 2.0 (1.4-3.0), 0.8 (0.3-2.4) and 2.2 (0.8-5.9), respectively.

Etidronate appears to have a better Ae profile. Bisphosphonate AEs are fairly mild, affect the gi system, occur most frequently in the presence of gi disease or concurrent use of NSAIDS and tend to be of the same type in the event of administration of a different bisphosphonate.