Bisphosphonates for osteoporosis
Examples
Generic Name Brand Name alendronate Fosamax etidronate Didronel etidronate with calcium carbonate Didrocal risedronate Actonel risedronate with calcium carbonate Actonel with Calcium zoledronic acid Aclasta You take most bisphosphonates by mouth—every day, once or twice a week, or even once a month. Zoledronic acid is given intravenously, usually only once each year.
Bisphosphonates are antiresorptive medications, which means they slow or stop the natural process that dissolves bone tissue. Bisphosphonates may be taken by men or women. They are taken by mouth, every day, once or twice a week, or even once-a-month.
How It Works
Bisphosphonates slow the rate of bone thinning, resulting in maintained bone density and strength. This may prevent the development of osteoporosis. If osteoporosis already has developed, slowing the rate of bone thinning reduces the risk of broken bones.
Why It Is Used
Bisphosphonates are commonly used for the prevention and treatment of osteopenia and osteoporosis.
Bisphosphonates are also used to treat other bone diseases such as Paget's disease.
Bisphosphonates should not be taken by:
- Pregnant women.
- People with severe kidney problems.
- People with severe heartburn or inflammation of the esophagus (the tube that connects the throat to the stomach).
How Well It Works
Studies show that alendronate (Fosamax) and risedronate (Actonel) lower the risk of fractures of the vertebrae by 50% and other fractures by 30% to 49% in people with osteoporosis. If you take alendronate or risedronate, you may not be as likely to break a bone.1 A study of post-menopausal women who took alendronate for 10 years reported increased bone density and effective prevention of fractures. This effect decreases if alendronate use is discontinued.2
Risedronate and alendronate may be taken in combination with hormone replacement therapy (HRT) for women with severe osteoporosis or for those who are not receiving adequate benefit from a bisphosphonate alone. Studies show that taking a bisphosphonate with hormone therapy results in increased bone mass when compared to taking either a bisphosphonate or estrogen alone.3, 4 However, the Women's Health Initiative study reports that HRT led to a small increase in a woman's risk of certain serious diseases; many experts recommend that long-term HRT only be considered for women with a significant risk for osteoporosis that outweighs the risks of taking HRT.5
Bisphosphonates should not be taken at the same time with parathyroid hormone (Forteo). Taking these medicines together does not build more bone density.6, 7 But taking the two medications at different times and in a specific order may build more bone density. For example, you could take parathyroid hormone for one year and then take a bisphosphonate for the following year to maintain or build bone density.8
In men, alendronate increases bone density in the spine and hip as well as total body bone density, and it helps prevent spinal fractures and decreases in height.9
Zoledronic acid reduces the risk of bone fracture in post-menopausal women. In one study, women had 70% less chance of fracturing a vertebra in their back and about 40% less chance of fracturing their hip.10
Side Effects
Side effects are uncommon if the medication is taken as directed, but may include:
- Heartburn, abdominal pain, and irritation of the esophagus.
- Headache and pain in muscles and joints.
- Constipation, diarrhea, and increased gas (flatulence).
- Difficulty swallowing (dysphagia).
- Allergic reactions.
Serious problems with bone healing, particularly after dental surgery, have been found in some people taking bisphosphonates.11 If you are taking bisphosphonates and need dental surgery, talk with your doctor.
Taking zoledronic acid may be linked to having an irregular heartbeat called atrial fibrillation.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
The long-term effects of taking bisphosphonates for many years are not known.
For best results and to decrease the risk of irritation to your esophagus
if you take bisphosphonates by mouth:
- Take bisphosphonates in the morning with a full glass of water at least 30 minutes before eating a meal, drinking a beverage, or taking any other medication.
- Sit or stand (don't lie down) for at least 30 minutes after taking a bisphosphonate. This helps prevent heartburn.
- Do not take a bisphosphonate late in the day if you forgot to take it in the morning.
If you are taking bisphosphonates, you should also take calcium and vitamin D supplements. However, calcium supplements may interfere with your body's ability to absorb bisphosphonates, so they should not be taken at the same time of day.
Complete the new medication information form (PDF)
(What is a PDF document?) to help you understand this medication.
| Author: | Douglas Dana Robin Parks, MS | Last Updated: February 21, 2007 |
| Medical Review: | Joy Melnikow, MD, MPH - Family Medicine Carla J. Herman, MD, MPH - Internal Medicine Andrew Swan, MD, CCFP, FCFP - Family Medicine | |
 | ||
| |
| Topic Contents | |
| Examples | |
| How It Works | |
| Why It Is Used | |
| How Well It Works | |
| Side Effects | |
| What To Think About | |
| References | |