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Fosamax: Does it really work?
I have been taking FOSAMAX (alendronate sodium) for the last two months because a bone scan revealed bone loss. I am in menopause and also on thyroxin. No other drugs. No one, not the pharmacist, my doctor, or any up to date books on drugs can give me any answers as to side affects, other than stomach irritation (which I do not have). My question is : What chemically is a biphosphonate and can there be side affects such as sleep disturbances or anxiety? I have felt more of the latter since taking it.
A Little Background About Fosamax
The new drug to which you refer is called Alendronate Sodium or its brand name is Fosamax. It has caused quite a bit of excitement because it is the first drug to reverse the bone loss of osteoporosis in post-menopausal women.
As you mention, it is a class of drugs called diphosphate. More specifically it is an aminobisphosphonate. Phosphates are an important element in bone formation. The structure of this drug combines phosphates with what is called an amino group. Amino groups are common in human biochemistry in a variety of settings. Amino acids often carry small electrical charges, and have a unique spatial configuration depending on their structures. With this drug, the amino groups' properties help the drug attach to its intended site of action--the bone. Once there, it can decrease bone loss.
Why Osteoporosis is So Important to Women
As you may know, osteoporosis is the loss of bone density that
occurs in post-menopausal women because of the hormonal
changes of menopause. As a result women who have the condition
suffer from more fractures. These fractures can lead to disability
and loss of independence for mature women. This is why your
bone density is more than an esoteric medical issue. Disabling
fractures have the potential to drastically alter a woman's lifestyle.
Increases Bone Density
Studies found that this drug reduced the bone loss that often
accompanies menopause. As a result, the average bone density
went up significantly in both the spine and the hip.
These are important places to check for bone density. The loss of
bone in the hip leads to the infamous "I've fallen and I can't get up"
hip fractures. Contrary to popular belief, often elderly do not fall
and then break their hip when they hit the ground. Rather, it is more
likely that their hip breaks due to the osteoporosis and then they
fall. This makes hip bone density all the more important, because it
indicates you can not prevent the fractures simply by stepping
carefully. Some people's hips can not be fixed such that they can
walk again, and thus they become dependent on others.
The spine can also spontaneously fracture in such a way that it
partially collapses on itself. This is called a compression fracture.
In the spine or vertebrae, the deformity can result in extremely
painful pinched nerves. This can also be disabling.
Less Vertebral Fractures
The real test for the drug is in the amount of reduction in the
fractures and disability. The studies showed that 48% less women
suffered the vertebral fractures, and there were 63% less vertebral
fractures. So in other words, in decreased a woman's chances of
getting any vertebral fracture, and decreased the number, if she
got one anyway. It also decreased the loss of height of the
vertebrae by 35%. This is important because it is a measure of the
compression fracture mentioned above. The more loss of height,
the more compression, the more likely to cause pain and disability.
Gastrointestinal Side Effects Were Prominent
Here's the complete, official list of side effects with the percentage of complaints with Fosamax vs. placebo. As many have told you, there are several stomach-related complaints with this drug. The difference between the two numbers what is most important, as people will as people will have some of these common symptoms from time to time. So, having some of these symptoms while on the drug may be a coincidence. The difference between the two is the percentage of people whose symptoms can reasonably be attributed to the drug. So, in other words, if the two numbers are very close, the association with the symptoms is likely a coincidence, not due to taking the drug. If the Placebo's group's number is higher, then there is likely no association.
Again the format is Symptom/Percentage or suffers on Fosamax/Percentage of suffers with placebo.
- Abdominal Pain 6.6/4.8
- Musculoskeletal Pain 4.1/2.5
- Nausea 3.6/4.0
- Dyspepsia (Upset Stomach) 3.6/3.5
- Constipation 3.1/1.8
- Diarrhea 3.1/1.8
- Flatulence 2.6/0.5
- Headache 2.6/1.5
- Acid Regurgitation (Heartburn) 2.0/4.3
- Esophageal Ulcer 1.5/0.0
- Vomiting 1.0/1.5
- Dysphagia (trouble swallowing) 1.0/0.0
- Abdominal Distention 1.0/0.8
- Gastritis 0.5/1.3
- Taste Perversion 0.5/1.0
- Dizziness 0.0/1.0
- Muscle Cramps 0.0/1.0
Your symptoms of anxiety and sleeplessness were not found to be a side effect of Fosamax. However, they are symptoms of too high of thyroid hormone levels, which one can get by getting an increased dose of thyroid medication. You mentioned that you took thyroid hormones. Fosamax was tested on women who were also taking thyroid hormones and no problems were discovered. However, the type of tests done were not adequate to say that there is no possibility of a drug interaction. In any case, I would speak with your physician about checking your thyroid levels first, and then looking for other possible causes of your symptoms.
The Most Important Questions About Fosamax Are Unanswered
The studies did not show that there were necessarily less pain or disability due to the increase bone mass and loss of height.
Also, with hip fractures the question has not yet been addressed. Although past epidemiological data predicts that the amount of bone density increase associated with the drug may result in less hip fractures.
So, does it work or not?
Fosamax does work on increasing bone density in two important areas. It significantly increases bone density in the hip and vertebrae. In medicine, the word "significant" has a specific meaning. It means that the drug caused bone density to increase and this has been demonstrated to be true beyond a reasonable doubt. It does not mean that the increase in bone density has to be very big. There is a causal relationship between bone density and fractures. But this doesn't mean that any amount of increase in bone density, no matter how small, will make a difference in fractures, pain, or disability.
In short, the statistical significance in studies found in this study (of Fosamax increasing bone density) doesn't mean that the drug will be significant in the common English use of the word. It doesn't mean it will make any difference in your life, if you take it.
In the vertebral bone studies, there were less fractures and less bone loss and height loss. The word Fracture sounds terrible, but in reality if you have a minor decrease in you vertebral bones, you may have no idea the problem is there. There was no evidence that Fosamax patients with the lesser bone loss were having less problems with the nerve pinching or other problems. Also, while the percentage of vertebral fracture were about cut in half, it means the percentage of women affected went from 6% to 3%. In summary, only 3% of the women could possibly be preventing clinical disease (pinched nerve) by taking this drug, and we are not sure if any of them actually are.
In the hip, we have no clinical data about as to whether or not it prevents hip fractures. It also doesn't tell us whether Fosamax increase the odds of having successful surgical repair, if one does break a hip. Whether or not a person with a hip fracture will be able to heal by having screws put in or having a hip replacement is dependent on having strong enough bone to anchor these devices. We only know it increases bone density by 5-6%. We don't know if that 5-6% is enough to make a difference in fractures and walking ability.
Summary
It's great to have a drug that actually increases bone density. Before the only response to osteoporosis was prevention.
Still, it is yet to be proven that the amount of increase in bone density caused will actually produce the real desired effect--less pain, fractures, and disability for women.
Should I take it?
Your risk factors, your personal medical history as it relates to osteoporosis, your tolerance for the gastrointestinal side effects, and your personal preferences will all come in to play in your decision. The research that will allow physicians to give you a more certain yes or no answer has yet to be done.
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