RT Journal Article
SR Electronic
T1 Duration of antiresorptive activity of zoledronate in postmenopausal women with osteopenia: a randomized, controlled multidose trial
JF Canadian Medical Association Journal
JO CMAJ
FD Canadian Medical Association
SP E1130
OP E1136
DO 10.1503/cmaj.161207
VO 189
IS 36
A1 Andrew Grey
A1 Mark J. Bolland
A1 Anne Horne
A1 Borislav Mihov
A1 Greg Gamble
A1 Ian R. Reid
YR 2017
UL http://www.cmaj.ca/content/189/36/E1130.abstract
AB BACKGROUND: Intravenous zoledronate 5 mg annually reduces fracture risk, and 5 mg every 2 years prevents bone loss, but the optimal dosing regimens for these indications are uncertain.METHODS: We conducted a 3-year open-label extension of a 2-year randomized, placebo-controlled, double-blind study. Late postmenopausal women with osteopenia were assigned to receive a single baseline dose of 1 mg, 2.5 mg or 5 mg of zoledronate or placebo. The primary outcome was change in spine bone mineral density (BMD). Secondary outcomes were changes in hip BMD and serum markers of bone turnover.RESULTS: The study involved 160 women. Zoledronate increased BMD and reduced markers of bone turnover in a dose-dependent manner. After 2 years, the 1-mg, 2.5-mg and 5-mg zoledronate doses increased spine BMD over placebo by 5.0% (95% confidence interval [CI] 3.0% to 7.0%), 5.7% (95% CI 3.7% to 7.7%) and 5.7% (95% CI 3.7% to 7.6%), respectively; after 5 years, the respective increases were 2.0% (95% CI −1.1% to 5.0%), 2.2% (95% CI −1.0% to 5.4%) and 5.1% (95% CI 2.2% to 8.1%). After 2 years, the 1-mg, 2.5-mg and 5-mg zoledronate doses increased total hip BMD over placebo by 2.6% (95% CI 1.3% to 3.9%), 4.1% (95% CI 2.9% to 5.4%) and 4.7% (95% CI 3.4% to 5.9%), respectively; after 5 years, the respective increases were 1.8% (95% CI −0.1% to 3.8%), 2.8% (95% CI 0.8% to 4.8%) and 5.4% (95% CI 3.5% to 7.3%). BMD remained above baseline values for 2–3 years in the 1-mg group, 3–4 years in the 2.5-mg group and at least 5 years in the 5-mg group.INTERPRETATION: The antiresorptive activity of single zoledronate doses of 1–5 mg persist for at least 3 years in postmenopausal women with osteopenia. Clinical trials would be justified to evaluate the effects on fracture risk of less frequent or lower doses of zoledronate than are currently recommended.Trial registration: www.anzctr.org.au, no. ACTRN12607000576426