In a 2007 study, once-yearly infusions of the bisphosphonate drug zoledronic acid (Reclast, Aclasta) lowered the incidence of fractures in postmenopausal women (JW Gen Med May 2 2007). Now, in another industry-sponsored randomized trial, 1199 men (age range, 50–85) at high risk for fractures received zoledronic acid (5-mg dose, given intravenously at baseline and at 12 months) or placebo. The study was open to men with osteoporosis defined by bone-density testing and to men with osteopenia plus one to three mild-to-moderate vertebral fractures identified by lateral spine radiographs.
At 2 years, the proportion of men with new radiographic vertebral fractures was significantly lower in the zoledronic acid group than in the placebo group (1.6% vs. 4.9%). A small difference in incidence of symptomatic vertebral or nonvertebral fractures (1.0% vs. 1.8%) did not reach significance. About 20% to 25% of zoledronic acid recipients developed fever, myalgia, or arthralgia (compared with about 5%–10% of placebo recipients), but the duration of these adverse effects was not reported. No cases of jaw osteonecrosis or atypical femoral fractures were noted, but myocardial infarction occurred in nine zoledronic acid recipients and in two placebo recipients (P=0.03).
Comment: A once-yearly infusion of zoledronic acid significantly lowered the incidence of radiographic vertebral fractures, but not clinical fractures, in this 2-year study in men. Infusions of this drug are known to cause transient flu-like symptoms; however, the small excess of myocardial infarctions was unexpected and is of some concern. In the trial in women that was cited above, zoledronic acid recipients experienced a higher incidence of serious atrial fibrillation (but not myocardial infarctions).
Source: Journal Watch General Medicine