Study Compares Osteoporosis Drugs for Side Effects, Efficacy

In a study comparing the efficacy and tolerability of two popular osteoporosis drugs, researchers found denosumab had a much greater effect on increasing spinal bone mineral density, while zoledronic acid caused more flulike symptoms. A group of researchers including investigators from the Osteoporosis & Metabolic Bone Disease Center at Loyola University Health System performed a retrospective chart review and survey of 107 patients to compare the efficacy, patient satisfaction, cost, and known adverse effects of denosumab in comparison to zoledronic acid, including muscle pain, back pain, and flulike symptoms. Denosumab, approved by the FDA in 2010 for use in postmenopausal women with osteoporosis, is injected subcutaneously every 6 months. The treatment works by inhibiting bone loss and fracture risks. Zoledronic acid, the most potent drug in its class, was approved by the FDA in 2007, is administered intravenously once every 12 months, and is designed to interfere with the bone-breakdown process. The denosumab and zoledronic acid groups were statistically similar in all areas with the exception of spine bone mineral density—which increased 0.060 g/cm2 versus 0.021 g/cm2, respectively—and flulike symptoms—none versus 29 percent of patients, the study authors noted. Both drugs “can be first-line agents for osteoporosis,” says Pauline Camacho, study investigator and director of the Osteoporosis & Metabolic Bone Disease Center at Loyola University Health System. The study, the first to compare the treatments head-to-head, was done “to determine if one is better than the other,” adds Camacho, noting that “there are limitations to our study, [in] that it was a retrospective study. However, [denosumab] did come out ahead in terms of bone density gains and less flulike symptoms after drug administration.” The findings were originally presented at the American Society for Bone and Mineral Research’s annual meeting in Baltimore, Md. —Mark McGraw