How Well Do Medicines Like Fosamax Work to Treat Osteoporosis?

Drug therapy for osteoporosis is recommended for those 50 and older with a history of past hip or spine fractures, those with hip or spine “T-scores” of negative 2.5 or less, and postmenopausal women or men 50 and older who don’t make that cut-off but have an estimated 20 percent or higher risk of a major osteoporotic fracture over the subsequent decade, or an estimated 3 percent or greater risk of hip fracture, specifically.

A T-score is a measure of how dense your bones are compared to a 30-year-old white woman. Since that’s the standard, and we tend to lose bone as we age, you can be labeled as having osteoporosis even if you have completely normal bone density for your age. Of course, just because your bone density may be normal doesn’t mean it’s necessarily optimal, which is why the National Osteoporosis Foundation set out those guidelines for drug treatment. Though another reason, perhaps, is because it gets substantial funding from the drug industry that rakes in literally billions of dollars in profits from osteoporosis drugs. What does the science say?

The primary drug class used to treat osteoporosis is the bisphosphonates, sold as such brands as Fosamax, Actonel, Boniva, and Reclast. They are most effective at reducing vertebral fractures, cutting the risk in postmenopausal women from 2.8 percent down to 1.4 percent. That’s a relative risk reduction of 50 percent, but an absolute risk reduction of only 1.4 percent, meaning you’d have to treat 71 women to prevent just one woman from getting a vertebral fracture.

Unfortunately, the diagnosis of vertebral fracture is kind of wishy-washy. Depending on how you define the changes on x-ray, the prevalence of vertebral fractures can vary by as much as 3 percent to 90 percent in the same elderly population—almost none, to almost all. They’re also poorly predictive of back pain or disability. Vertebral fractures can certainly lead to back pain and reduced physical function, but only about a third are symptomatic at all. The most harmful fractures are hip fractures.

Despite most of the clinical trials for osteoporosis treatment being funded by the drug companies themselves, no primary prevention benefit from bisphosphonates has been found for hip fractures. In other words, taking these drugs has not been convincingly shown to prevent fracturing your hip in the first place. However, having a prior fracture doubles your risk of breaking another bone; so, for those at high risk, bisphosphonate drugs may decrease the odds of hip fracture by 25 percent, though the absolute risk reduction is, again, only about 1 percent. It may take treating 91 people for three years to prevent one hip fracture.

An overconfidence in the power of pills and procedures for disease prevention may be one of the reasons doctors and patients alike may undervalue diet and lifestyle approaches. In this study, patients were asked to estimate the number of fractures or deaths prevented in a group of 5,000 patients undergoing each drug intervention over a period of 10 years. The vast majority of people tended to wildly overestimate the ability of mammograms and colonoscopies to prevent cancer deaths, the power of drugs like Fosamax to prevent hip fractures, and drugs like Lipitor to prevent fatal heart attacks. No wonder most people continue to rely on drugs to save them! But the dirty little secret is that most people said they wouldn’t be willing to take many of these drugs if they knew how little benefit these products actually offered.

In a survey of those undergoing bone density scans, the average five-year fracture risk that would motivate most participants to consider preventative medication was 50 to 60 percent—much higher than their actual risk. Most patients want to be told the truth. They want to be told what the chances are that the drugs will actually benefit them, but there is a tension between the patient’s right to know and the likely reduction in their willingness to take the drug if they knew the truth.

In the bone density scan survey, participants greatly overestimated their own personal risk for hip fracture, thinking it was around 19 percent over the next five years, which is more than 10 times higher than their actual risk of 1.4 percent. Rather than disabusing them of this overestimate, some suggest physicians should do the opposite: stoke fear in patients who “refuse to comply with medication recommendations” by increasing their “perceived susceptibility to fragility fractures” as well as their “perceived severity of suffering from a fragility fracture.” Since emotion can be more motivating than reason, and “anecdotal” evidence can be more effective than “evidence” evidence, a “graphic scenario of suffering and incapacitation after a hip fracture will enhance emotional perception of this threat.”

But hip fractures can, indeed, be devastating and are associated with a significant risk of ensuing death. So, what about all the lives these drugs must be saving? Well, only about a quarter of the deaths following fractures may be attributable to the fracture itself; so, most of the mortality risk may just be a consequence of the comorbidities—that is, the other diseases and poor health status of people who tend to fracture their hips. So, they might have died anyway in that same time frame even if they hadn’t broken any bones. This may help explain why there are no saved lives. Osteoporosis drug treatments, particularly bisphosphonates, fail to significantly reduce overall mortality.