Risedronate for preventing fractures caused by osteoporosis in postmenopausal women

This summary of a Cochrane review, presents what we know from research about the effect of Risedronate for preventing fractures (broken bones) caused by osteoporosis.

In women who have already been diagnosed with low bone density putting them at risk for fracture or have already had a fracture in the bones of their spine, risedronate:

- probably prevents fractures in the bones of the spine and in bones other than in the spine;

- may prevent hip fractures;

- may not lead to any difference in wrist fractures.

 

In women whose bone density is closer to normal or who may not yet have had a fracture in the bones of their spine, risedronate:

may not lead to any difference in fractures in the bones of the spine, hip fractures or wrist fractures;

there is not enough information to tell if Risedronate prevents fractures in bones other than in the spine.

We do not have precise information about side effects and complications. This is particularly true for rare but serious side effects. Possible side effects may include digestive problems such as damage to the throat, esophagus and stomach and, less commonly, reduced blood supply to the jaw bone, which causes the bone tissue to breakdown .

What is osteoporosis and what is risedronate?
Bone is a living, growing part of your body. Throughout your lifetime, new bone cells grow and old bone cells break down to make room for the new, stronger bone. When you have osteoporosis, the old bone breaks down faster than the new bone can replace it. As this happens, the bones lose minerals (such as calcium). This makes bones weaker and more likely to break even after a minor injury, like a little bump or fall. Women who have gone through menopause are more likely to get osteoporosis than other people.

Risedronate belongs to the class of drugs called bisphosphonates. It is a type of medication that slows down the cells that break down the old bone.

Best estimate of what happens to women that have already been diagnosed with low bone density putting them at risk for fracture or have already had a fracture in the bones of their spine, who take Risedronate:

 

Fracture of the spine

                 - 14 out of 100 women had a fracture when taking a placebo

                 - 9 out of 100 women had a fracture when taking Risedronate

 

Fracture in the hip

              - 3 out of 100 women had a fracture when taking a placebo

                 - 2 out of 100 women had a fracture when taking Risedronate

 

Fracture in the wrist

                 - 4 out of 100 women had a fracture when taking a placebo

                 - 3 out of 100 women had a fracture when taking Risedronate.

 

Fractures in bones other than the spine

                 - 10 out of 100 women had a fracture when taking a placebo

                 - 8 out of 100 women had a fracture when taking Risedronate

 

Best estimate of what happens to women whose bone density is closer to normal or who may not yet have had a fracture in the bones of their spine who take risedronate:

                 - there is no difference in the number of women out of 100 who will have a spine fracture. This may be the result of chance.

                 - for hip and wrist fractures, it is not possible to calculate the effect because no one had fractures of the hip or wrist in the studies.

                 - there is not enough information to tell if Risedronate prevents fractures in bones other than in the spine.

 

Authors' conclusions: 

At 5 mg/day a statistically significant and clinically important benefit in the secondary prevention of vertebral, non-vertebral and hip fractures was observed, but not for wrist. The level of evidence for secondary prevention is Gold (www.cochranemsk.org) for vertebral and non-vertebral and Silver for hip and wrist. There were no statistically significant reductions in the primary prevention of vertebral and non-vertebral fractures. The level of evidence is Silver.

Read the full abstract...
Background: 

Osteoporosis is an abnormal reduction in bone mass and bone deterioration leading to increased fracture risk. Risedronate belongs to the bisphosphonate class of drugs which act to inhibit bone resorption by interfering with the activity of osteoclasts.

Objectives: 

To assess the efficacy of residronate in the primary and secondary prevention of osteoporotic fractures in postmenopausal women.

Search strategy: 

We searched CENTRAL, MEDLINE and EMBASE. Relevant randomized controlled trials published between 1966 to 2007 were identified.

Selection criteria: 

Women receiving at least one year of risedronate for postmenopausal osteoporosis were compared to those receiving placebo or concurrent calcium/vitamin D or both. The outcome was fracture incidence.

Data collection and analysis: 

We carried out study selection and data abstraction in duplicate. Study quality was assessed through the reporting of allocation concealment, blinding and withdrawals. Meta-analysis was preformed using relative risks and a >15% relative change was considered clinically important.

Main results: 

Seven trials were included in the review representing 14,049 women.

Relative (RRR) and absolute (ARR) risk reductions for the 5 mg dose were as follows. Risk estimates for primary prevention were available only for vertebral and non vertebral fractures and showed no statistically significant effect of risedronate on fractures. For secondary prevention, a significant 39% RRR in vertebral fractures (RR 0.61, 95% CI 0.50 to 0.76) with 5% ARR was found. For non-vertebral fractures, a significant 20% RRR (RR 0.80, 95% CI 0.72 to 0.90) with 2% ARR and for hip fractures there was a significant 26% RRR (RR: 0.74, 95% CI 0.59 to 0.94) with a 1% ARR. When primary and secondary prevention studies were combined, the reduction in fractures remained statistically significant for both vertebral (RR 0.63, 0.51 to 0.77) and non vertebral fractures (RR 0.80, 0.72 to 0.90)

For adverse events, no statistically significant differences were found in any of the included studies. However, observational data has led to concerns regarding the potential risk for upper gastrointestinal injury and, less commonly, osteonecrosis of the jaw.

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