Easier-to-take treatment may be an option for osteoporosis

A once-a-year treatment to reduce the risk of the brittle-bone disease osteoporosis may work as well asdaily pills now on the market, a new study suggests.

An intravenous version of the oral drug zoledronic acid, which is already used to treat other bone disorders, may prevent hip and spine fractures with one annual infusion, according to research in Thursday's New England Journal of Medicine.

Epidemiology Prof. Dennis Blackof the University of CaliforniaSan Francisco and his colleagues followed, over three years,more than 7,736 women with osteoporosis who were betweenages 65 and 89. Half the study participants had an annual infusion with zoledronic acid and half had a placebo infusion.

About 11 per cent of post-menopausal womenget spine fractures. In the study, funded by the drug's manufacturer, the risk was reduced to about three per cent among women who received the annual infusion, comparedto 10 per cent for placebo.

For hip fractures, the risk dropped from 2.5 per cent to 1.4 per cent.

Some drugs a nuisance to take: doctors

About 1.4 million Canadians a large majority of them women have osteoporosis, which increases the risk of broken bones. In Canada, the cost of treating osteoporosis and related fractures is estimated to be $1.9 billion a year, according to Osteoporosis Canada.

Doctors say even though osteoporosis medications known as oral bisphosphonates are effective, many patients find them a nuisance to take.

After a year, half of those prescribed the drugsare still taking them, said Dr. Gillian Hawker, a rheumatologist at Women's College Hospital in Toronto.

"If people aren't taking their drug at least two-thirds or more of the time, they don't get the benefit in terms of fracture prevention," said Hawker.

For 70-year-old Betty Bisnair of Windsor, Ont., the pills bothered her stomach and were difficult to take, she said.

"You got to take it with a full glass of water, and you got to wait an hour or two hours before you can lie down or eat," Bisnair said.

For patients who can't or won't take the oral drugs, an intravenous version might be a solution. Doctors say it is important to find treatments that patients will stick with, given that many elderly people who go into hospital with a broken hip or spine develop complications, and die or end up in nursing homes.

Fewer fractures

"What we want to do is find out what works best for each individual patient," said study investigator Dr. Jonathon Adachi, a rheumatologist with St. Joseph's Healthcare in Hamilton, Ont. "I think that's the way that most of us are going to approach this."

The findings suggest the once-a-year treatment is as effective as the daily or weekly oral bisphosphonate medications such as Fosamax or Actonel, said Hawker, who cautions there was an unexpected increased risk of irregular heartbeat.

Most cases of atrial fibrillation appeared more than a month after the treatment was given.

"There isn't a good explanation for that, so I think it warrants a little bit more attention," said Hawker. There was also a slight increase in minor side-effects such as fever or muscle pain, mostly within three days of the first injection.

Health Canada is reviewing an application to allow doctors to prescribe zoledronic acid for osteoporosis. Doctors may prescribe it off label, with the patient picking up the cost of about $650 a year.