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Sunday, January 15, 2012

Some interesting new studies: Should you take aspirin to prevent heart attacks? Do statin medications cause diabetes? Does marijuana smoking cause lung disease?

This week has been really interesting in the medical journals. Although I often question the relevance of population based medical research to guide treatment of individuals, large trials are excellent for helping us question widely held beliefs. Since doctors are often unreasonably convinced that they are right, studies that make us question ourselves are valuable.

Last year when reviewing recommendations of the US Preventive Services Task Force and looking at the studies on which these recommendations were based, I began to recommend regular use of aspirin for men over the age of 45 and women over the age of 55 to prevent heart attacks. This month an article came out in the Archives of Internal Medicine that showed that for patients without heart disease, there was no decrease in  mortality with regular aspirin use and that the reduction in risk of heart attack and stroke is really quite small. Risk of bleeding related to taking even a baby aspirin is significant. This only leads me back to my previous position on the subject, which was that each individual should look at his or her risk for heart attack and stroke and weigh their risk associated with aspirin use and then decide if using it will make sense. The USPSTF had labeled aspirin use as a level A recommendations, suggesting that there was good medical evidence that it helped. They will probably change that, but usually those changes take awhile.

Use of statins for primary prevention of heart disease (that is prevention of heart attack or angina in patients who are not already known to have coronary artery disease) has been something I have hesitated to recommend. Statins, such as lipitor, have such powerful effects on so many systems that using them in patients who are otherwise healthy worries me. Cardiologist seem to be positively enamored of statins, and it seems that very little time passes between studies that show yet another benefit of statin therapy. As a primary care physician I saw many patients with side effects of statins, including muscle pains and stomach problems, many of which were not recognized as side effects until the medication was stopped. It just can't be good to take something that makes you feel miserable, even if that something doesn't kill you or cause organ failure. Many of my patients voted with their feet on the statin issue and just quit taking the medicine even after I had prescribed it and made a good case for using it. Statin safety was addressed in an article, again in the Archives of Internal Medicine this month that showed that in the Womens' Health Initiative patients on statins had about a 1.5 times average risk of developing diabetes. This was corrected for such issues as weight and other known risk factors. I can imagine that such a finding might still be just an association, since doctors might have put patients on statins due to perception of their risk for diabetes since diabetes often goes hand in had with elevated cholesterol levels. Still, I harbor ongoing suspicion of statin drugs since their manufacturers have made such an obscene amount of money on them which in turn fuels more advertising and feeds back to influence both clinicians and researchers. It will be interesting to see how this piece of data pans out since diabetes is hardly an acceptable medication side effect.

Finally, in the Journal of the AMA (JAMA) an article addressed the lung risks of long term marijuana smoking. An Article in the Archives of Internal Medicine in 2007 reported that marijuana dilated the small airways, which would tend to be a good thing, but was only able to say that long term smokers of marijuana often had a productive cough. In this article, pulmonary function testing was done regularly in a group of over 5000 patients who were being followed to look at risk of heart disease. These patients had periodic testing of lung function and, on average, low frequency but long term use of marijuana was not associated with lung disease and even frequent marijuana use was not clearly bad for the lungs. Marijuana smokers did have an increase in lung capacity that was theorized to be due to the fact that they learned how to take deeper breaths. I have certainly seen patients who have lung disease that looks much like that of my tobacco smokers even though they only use marijuana, and studies like this do not prove that marijuana is safe for everyone's lungs. Still, marijuana use is by no means equivalent to cigarette use in terms of respiratory complications. I suspect we will never see a study that looks at effects of smoking the amount of marijuana equivalent to a pack of cigarettes a day. Other complications of that level of use would probably eclipse breathing issues.

Saturday, January 14, 2012

Good news about health care costs!

Happy New Year! According to Health Affairs, a journal of health economics, the rise in health care spending in the US is flat, and spending on physician's services rose at an all time low number of 1.8%. The interpretation of this information is that health care, even though it is considered a necessity, has been impacted by the weak economy. That is certainly a factor, but it is interesting to see that health care spending can go down without the quality of care looking catastrophically worse In fact it looks like there are many areas of improved care in the last two years. My guess is that spending came down because there is enough fat (and there is still more fat) that can be cut just by physicians and consumers being aware of what is of value in medicine. We are probably also seeing effects of preparing for and responding to health care reform in a way that has reduced waste.

So happy New Year! We have started the year with health care costs that have risen only as fast as the GDP. We can do better, yes, but it is clear that better is the direction in which we are moving.

Is Pradaxa (dabigatran) dangerous? Comparing Pradaxa, Xarelto and warfarin

Just today while poking through studies recently released, I came upon an article that added to my growing discomfort with using Pradaxa, an anticoagulant ("blood thinner") that is now being widely used as an alternative for warfarin (coumadin is the brand name) for people with atrial fibrillation in order to reduce their risk for stroke.

Atrial fibrillation is a condition in which the atrium (entry chamber) of the heart wiggles rather than beats, and is caused by high blood pressure, valve problems, alcohol abuse and a number of other factors. The wiggling rather than beating atrium can build up blood clots which can migrate into arteries all over the body, but most devastatingly in the brain to cause strokes. Taking an anticoagulant reduces this risk. But blood has a very good reason for clotting, and when it is inhibited from clotting, a person can bleed, sometimes catastrophically, from an injury or an ulcer or a weak area in the tissues of the body. Like the use of any drug, anticoagulant use involves considering whether risks are less than expected benefits. Warfarin, our old standard drug, required that we monitor the level of anticoagulation with a blood test about every month. This was annoying and resource consuming, but had the effect of keeping us in contact with our patients and of making them realize, monthly, that there was risk associated with taking the drug. It was not uncommon for the level to drop too low to be protective, or to rise to the point that serious bleeding could occur. Still, most patients did fine. The drug became generic a few years ago so its cost was not too significant, and insurance covered the blood tests and followup.

Pradaxa, on the other hand, requires no monitoring. It is dosed twice daily rather than once, as for warfarin, but it is great to not have to worry about monthly visits. Warfarin blocked the action of vitamin K, so could be reversed by eating foods with lots of vitamin K, so patients had to be careful with their diets. Pradaxa has no such restrictions. Because Warfarin blocked vitamin K as its main mechanism of action, giving high doses of vitamin K was pretty effective in stopping bleeding if a person was injured or needed surgery, and if we needed to reverse it even more quickly we could use blood plasma. In the case of Pradaxa, though, there is no known agent that reverses its effects, though its effects do fade in about 24 hours. Unlike warfarin which takes days to become effective, pradaxa works in less than an hour, which in some situations might be life saving.

I was a great fan of Pradaxa when it first came out because my patients really did hate to get regular blood tests with warfarin and sometimes their doses were very difficult to stabilize. I saw many bleeding complications over the years that I practiced with warfarin, and occasionally strokes when the dose was too low. I woke up to problems with Pradaxa when I went to an Advanced Trauma Life Support course and found that the surgeons who dealt with patients who are injured were very opposed to anticoagulants, especially ones that couldn't be reversed. Patients who had trauma to their heads or abdomens and were on such drugs would bleed and die and the surgeon would have to sit by and watch. The surgeons asked why internists like myself would push so strongly to get patients to take these drugs to reduce risk of stroke, when the patient might just as easily die of bleeding should they fall or be in a car accident.

The article that just came out was in the Archives of Internal Medicine this month and showed that patients who took Pradaxa were 1.33 times as likely as patients who took no anticoagulants, aspirin or warfarin to had heart attacks or near heart attacks. I have no real idea why this would be, but the study was large and performed at several centers, so apparently something about this drug may make microclots in the coronary arteries occur or make platelets more sticky. In any case, it sure makes me think twice about using it.

Just very recently another drug like Pradaxa was released for use, and it may be better. The brand name is Xarelto, generic name Rivaroxaban. This drug is dosed once daily and can be reversed with a blood product called prothrombin complex. Its official indications are broader than Pradaxa. It can be used both for atrial fibrillation and preventing blood clots in the legs of patients who have had hip or knee replacements. It's likely that both Pradaxa and Xarelto are good for any clotting condition, but the FDA is slow to expand its recommendations due to the fact that blood clotting conditions are very risky, and there are other drugs that have long histories of effectiveness.

The cost of these new anticoagulants is really steep. Drugstore.com quotes a price of $245 for a month's supply of Pradaxa, and looking at sources online for Xarelto, costs for that will be really similar. Warfarin only costs about 15 dollars a month, but monitoring and complications bring the cost up significantly in the big picture. Both of the new drugs are less likely to cause fatal bleeding than warfarin.

So the answer to the question "is Pradaxa dangerous?" is "of course!" which also is true of Xarelto and warfarin.

Wednesday, January 4, 2012

Christian Science, faith healing and mind-body medicine with mention of the work of Elisabeth Fischer Targ MD

Just this last week I saw a couple of ancient people who were at the end of their lives, had been very healthy up until recently and had received close to no medical care for nearly 9 decades. One of them was a devout Christian Scientist and the other was a Seventh Day Adventist. Christian Science began in 1871 based on the teachings of Mary Baker Eddy, and follows her teachings as laid out in her blockbuster bestselling book Science and Health with Key to the Scriptures which has been translated into just about every known written language and outlines the philosophy and practice of healing based on Christian faith. Seventh Day Adventists also have pretty strict health prescriptions and many of them eat a plant based diet, avoiding animal products, especially meat. I have had other Christian Science patients in the past, of great age, and am very curious about what draws them to it and how they weave it into their very healthy lives.

Mary Baker Eddy was a "sickly child" who heard voices and was known as someone who could heal sick animals. She remained sick for much of her adult life, even giving up care of her only son due to illness. She believed (and this is based on a pretty cursory look at her book, so take it with a grain of salt) that God and the spirit, love and truth and good, were all the real things of existence, and material things, including the body and matter in general, were false and mostly unimportant. Regarding healing she wrote "When the sick are made to realize the lie of personal sense, the body is healed." She described her religion as "primitive Christianity" and the churches she established were very popular and remain so, to some extent. One of the publications that began with the movement, the Christian Science Monitor, is still very active and an excellent source of non-partisan news.

I am neither a devout Christian nor an integrative medicine specialist or mind-body practitioner, yet I have had a longstanding interest in the power of meditation and focused thought or visualization to heal. Even at Harvard, that bastion of evidence based medicine, we see practitioners looking to find the science behind the success of various relaxations techniques and spiritual practices in curing illness and promoting wellness. A rather funny animal model of meditation (which I heard about at the Mind-body medicine course I just attended last month at Harvard) is allowing rats to shred pieces of compressed fiber to make nests. The happy shredders heal up experimentally inflicted burns much faster than their bored and idle litter mates.

I think that Mary Baker Eddy must have been sick with one of the diseases that is primarily characterized by pain and fatigue, like fibromyalgia, migraine headaches or chronic fatigue syndrome, since she died in her late 80s despite years of being ill in a time when medical care was at best ineffective and at worst toxic. Even now, though we have potions and pills galore for these conditions, most of them work poorly, with high costs and sometimes devastating side effects. I suspect that faith healing was a truly excellent approach for what she had, though it might not have been so effective had she suffered from tuberculosis or vitamin B12 deficiency.

What I end up with, after looking at the lives of healthy very old Christian Scientists, is a respect for their particular path. Much of what we, as physicians, hand out for diseases will someday be found to be at least as bad as blood letting, which does in fact work pretty well for both acute congestive heart failure and hemochromatosis. In a couple of decades we will cringe as we think of the patients who we treated with chemotherapy drugs for cancer who died of side effects with no significant beneficial effects on their tumors. I have seen a few tragic results of using faith healing to treat cancers, but I have also seen people who were diagnosed with relatively small tumors, treated with chemotherapy agents that made them feel terrible and died anyway. It seems clear that there are some people and some diseases that probably respond dramatically to faith healing and some that respond dramatically to the right chemotherapy drug.

My best friend in college, Elisabeth Targ, graduated from Stanford and became a psychiatrist who had a special interest in remote healing by non-denominational prayer. She attempted to rigorously test the effect of distant prayer on patients with AIDS and saw a significant improvement in their outcomes. The study was later questioned, but she was pretty impressed with the results when I talked to her before her death. She died of a very nasty brain tumor in 2002 despite prayer and psychic healing attempts from her very wide range of friends. The problem was, I think, that she just had a really bad disease that neither surgery, radiation, chemotherapy nor as yet undescribed psychic processes could cure. Watching her struggle with the side effects of her expensive chemotherapy drugs I would say that the psychic part of the healing was not nearly so nasty. Kind of nice, actually.

I think psychic healing and faith healing probably have an effect that is mediated by some of the same processes that are involved in the less far-out practices that are part of mind-body medicine. Meditation and guided imagery will be more easily accepted by the medical field because we come closer to understanding them and can more easily test them. The science involved in this will continue to be really difficult to do well, because you can't have a control group "pretend" to meditate, since even pretend meditation is meditation. Practices that can be taught and learned and repeated without medical supervision will be attractive for payers and this will partially counter the medical profession's reticence to use techniques that they feel are unscientific. Already the teachings of John Kabat-Zinn have been codified into a curriculum called "Mindfulness Based Stress Reduction" which has been spectacularly effective in treating conditions such as anxiety, chronic pain and insomnia. We will continue to learn what these sorts of things are good for, and perhaps we will move ever so slightly away from the modern approach of a pill for every problem.