Benefits and risks of osteoporosis drugs

Last updated: February 2010

If you've been given a diagnosis of osteoporosis your doctor will probably prescribe a bisphosphonate, a class of drugs that helps preserve and build bone. Alendronate (Fosamax, Fosamax Plus D, and generic), the first bisphosphonate approved by the Food and Drug Administration for the treatment and prevention of osteoporosis, came on the market in 1995 and proved to be a moneymaker, bringing in nearly $3.2 billion in 2005.

That success likely contributed to the introduction of several related drugs to treat osteoporosis, including some in more convenient doses, such as the heavily advertised ibandronate (Boniva), which can be taken orally just once a month or intravenously once every three months. There is also the once-a-year injection drug, zoledronic acid (Reclast, Zometa).

But research has found that bisphosphonates offer only modest benefits in building bone and preventing fractures. And all pose risks. Growing evidence has now linked the drugs to a long list of worrisome side effects. Those concerns have recently taken on added urgency as many doctors have started prescribing bisphosphonates not just for people with outright osteoporosis but also for those with osteopenia, or pre-osteoporosis, even though it's less clear that the drugs are effective for this less serious but more common condition.

Here's a rundown on the benefits and risks of the drugs, some guidelines to help you decide when these drugs might be worthwhile, and some nondrug alternatives that may reduce or even eliminate your need for medication.

Modest benefits

Bisphosphonates are a proven remedy for preventing fractures in people with osteoporosis, but that benefit is relatively modest. A pivotal study, for example, found that 13.5 percent of women with the disease who took alendronate experienced a fracture compared with 18 percent of those who took a placebo. Other analysis found that 22 women with a history of an osteoporosis-related fracture would need to be treated for three years to prevent another one. At the same time, 100 women with severe bone loss would need to be treated for three years to prevent one hip fracture.

For people with bone loss from the long-term use of corticosteroids such as prednisone, bisphosphonate therapy improves bone-mineral density in the lower spine by about 4 percent. But it doesn't cut the number of spinal fractures, according to a comprehensive review by the Cochrane Collaboration. It is even less clear that the benefits of using these drugs to treat women with osteopenia are worth the cost and the potential side effects.

Growing risks

Those modest benefits need to be balanced with the risks, which have been increasingly evident since alendronate was introduced more than 14 years ago.

Early studies of the drug, for example, suggested that it was no more likely than a sugar pill to cause gastrointestinal problems. But within a year of its introduction, reports of adverse events, including injuries to the stomach and esophagus, began pouring in. That prompted Merck, the manufacturer, to issue revised labeling for the drug. And that was just the start. Alendronate has received an eyebrow-raising 16 FDA-mandated changes to its label related to updates on its safety and side effects.

Some of those problems—throat or chest pain, difficulty swallowing, and heartburn—can be managed by taking certain precautions. But research has increasingly linked bisphosphonates to less common but more serious and long-lasting problems, including an abnormal heart rhythm (atrial fibrillation); incapacitating bone, joint, and muscle pain; and bone loss in the jaw (osteonecrosis). Some evidence suggests long-term use may actually increase the risk of a certain type of fracture.

Nondrug alternatives

The modest benefits of the drugs combined with their potentially serious risks put a premium on using safer alternatives. Fortunately, there are a number of nondrug measures that can help prevent fractures by building bone, preventing falls, or both.

Get the right nutrients. Supplemental calcium and vitamin D can strengthen bones. Experts currently suggest that most people get at least 800 to 1,000 international units of vitamin D from their diet (including fortified foods) or supplements, and 1,200 mg of calcium for people 50 and older. Those with weakened bones should talk with their doctor about how to get 1,500 mg daily.

Exercise. Any activity that puts pressure on the bones, including walking, dancing, and other weight-bearing aerobic activities, can also build bone. So can strength training. Those exercises also build muscle and improve balance, both of which can help prevent falls that cause fractures. Exercises such as tai chi may also help by improving balance.

Prevent falls. Limit your consumption of alcohol, especially near bedtime, to help prevent falls on nocturnal trips to the bathroom, and avoiding sleeping pills if possible for the same reason. Have your eyes checked, too, so you can see where you're going, and be sure the areas of your home where you walk have plenty of light. And make your home fall-proof by keeping extension cords out of the way, installing grab bars in the bathroom and rubber mats in the bathtub or shower, and getting rid of loose rugs.

Should you take a drug to treat osteoporosis or osteopenia?

Deciding whether you need a bisphosphonate should start by determining your risk of osteoporosis. You and your doctor should consider such factors as your age, race, and family and medical history. He or she should also arrange for a test called a DXA scan, which will, by using a pencil-thin x-ray beam, measure bone density at your hips, spine, and possibly your wrists.

The DXA score is compared with the average score of 30-year-old women. The comparison, called a T-score, is expressed as standard deviations (SD) from that average. The lower the score, the higher the fracture risk. A T-score of minus 2.5 SD or less defines osteoporosis, while a score between minus 1 and minus 2.5 SD is considered osteopenia. To make diagnoses more standard, the World Health Organization recently developed a calculator that uses those and other risk factors, plus the DXA results, to predict a person's 10-year probability of having a fracture. Known as FRAX, the online tool is available here, and is expected to shift treatment toward those who really need it.

But not everyone requires the test. Consumer Reports medical advisers say that women should have their bone density measured at age 65, men at 70. Postmenopausal women under that age and men 50 and older should be screened if they:

  • Are unusually thin or smoke.
  • Have had a fracture from a minor trauma, or have a parent who had an osteoporosis-related fracture.
  • Have a disease (thyroid or parathyroid disorders, celiac disease, adrenal hyperactivity) or regularly take a medication, such as steroids or certain antiseizure drugs, that causes bone loss.

People who learn from the test that they have osteopenia often only need to take the nondrug steps to strengthen their bones and prevent falls. The case for bisphosphonates is stronger for people with outright osteoporosis or a history of fractures, but even they should balance the risks and benefits.

If you do opt for a drug, it generally makes sense to consider starting with generic alendronate since it's significantly less expensive. And talk with your doctor about the steps you can take to reduce your risk of side effects. If you've taken a bisphosphonate for five years or more, ask your doctor about stopping temporarily to encourage normal bone remodeling and to reduce the risk of side effects.

Bottom line. Bisphosphonates offer only modest benefits in building bone and preventing fractures, and that should be considered along with the risks. Before you start taking one, some of the questions to ask your doctor include:

  • Do you think I need to have my bone density measured and if so, why?
  • Do you think I need a drug or will supplemental calcium, vitamin D, and nondrug measures suffice?
  • If I do take a bisphosphonate, which one do you think would be best for me, and why?
  • What are the most common side effects and what can I do to minimize them?
  • What are my risks if I do not take medication for this condition?

This drug safety alert is made possible through a partnership between Consumer Reports Best Buy Drugs and the Research on Adverse Drug Events and Reports (RADAR) group, a pharmacovigilance group led by Charles Bennett, M.D. Ph.D. M.P.P.

These materials are made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by the multi-state settlement of consumer-fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).

If you think you have experienced an adverse event with this drug or any drug, especially if it is of a serious nature, it is important to 1) tell your doctor immediately and 2) report the event to the Food and Drug Administration via the FDA's MedWatch Web site at or by calling 1-800-FDA-1088.

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