just one single dose of a particular osteoporosismedicine may be enough to help patients â€” even those who are very frail. i'm rachelle grossmanwith today's health news. a new study found that zoledronic acid, sold under the brandname reclast, may improve bone mineral density in frail, elderly women living in long-termcare facilities. in fact, a single dose may be effective for up to two years. a new studyfound that the drug improved bone density and reduced bone turnover for two years. osteoporosisis a disease that causes bones to become weak and brittle. while it affects both men andwomen, older women who have gone through menopause face the highest risk, according to the nationalosteoporosis foundation.