It has long been recognized that there are substantial multifactorial placebo effects that create real and illusory improvements in response to even an inactive treatment. There is a tendency, however (especially in popular discussion), to oversimplify placebo effects – to treat them as one mind-over-matter effect for all outcomes. Meanwhile researchers are elucidating the many mechanisms that go into measured placebo effects, and the differing magnitude of placebo effects for different outcomes.
For example, placebo effects for pain appear to be maximal, while placebo effects for outcomes like cancer survival appear to be minimal.
A recent study sheds additional light on the expectation placebo effect for pain. The effect is, not surprisingly, substantial. However it does not extrapolate to placebo effects for outcomes other than pain, and the results of this very study give some indication why. From the abstract:
The effect of a fixed concentration of the μ-opioid agonist remifentanil on constant heat pain was assessed under three experimental conditions using a within-subject design: with no expectation of analgesia, with expectancy of a positive analgesic effect, and with negative expectancy of analgesia (that is, expectation of hyperalgesia or exacerbation of pain).
What they found was that the positive expectation group reported twice the analgesic effect as the no expectation group, and the negative expectation group reported no analgesic effect. This is a dramatic effect, but not surprising.
Ear infections used to be a devastating problem. In 1932, acute otitis media (AOM) and its suppurative complications accounted for 27% of all pediatric admissions to Bellevue Hospital. Since the introduction of antibiotics, it has become a much less serious problem. For decades it was taken for granted that all children with AOM should be given antibiotics, not only to treat the disease itself but to prevent complications like mastoiditis and meningitis.
In the 1980s, that consensus began to change. We realized that as many as 80% of uncomplicated ear infections resolve without treatment in 3 days. Many infections are caused by viruses that don’t respond to antibiotics. Overuse of antibiotics leads to the emergence of resistant strains of bacteria. Antibiotics cause side effects. A new strategy of watchful waiting was developed.
What does honey bee colony collapse disorder have to do with a potential new cancer treatment?
They both relate – in a convoluted manner – to an old antibacterial drug called nitroxoline.
True to my devotion as a natural product pharmacologist, I’m proud to say that new life would not have come to nitroxoline had not a fungal natural product called fumagillin been studied as an antiangiogenic anticancer drug – one that inhibits the formation of new blood vessels.
Working in pharmacies where supplements are sold alongside traditional (over-the-counter) medications, I’m regularly astonished at the different perceptions consumers can have about the relative efficacy and safety of different types of products. Once, speaking with a customer about a medical condition she wanted to treat, I indicated that there were no effective non-prescription therapies — she needed to see a physician for access to an effective treatment by prescription — and I gestured behind the counter. “Back there?!” she pointed. “That’s where you keep the stuff that kills people! I want something natural!” Suggesting that my patients with heart disease or HIV had a somewhat different perspective, I tried (unsuccessfully) to talk her out of a questionable-looking supplement (Hint: avoid anything from a company with a P.O. box as a mailing address.) This appeal to nature, combined with a perception that natural products are safe, and conventional drugs are unsafe, is pervasive. (more…)
In discussing “alternative” medicine it’s impossible not to discuss, at least briefly, placebo effects. Indeed, one of the most common complaints we at SBM voice about clinical trials of alternative medicine is the lack of adequate controls — meaning adequate controls for placebo and nonspecific effects. Just type “acupuncture” in the search box in the upper left hand corner of the blog masthead, and you’ll pull up a number of discussions of acupuncture clinical trials that SBM bloggers have written over the last three years. If you check some of these posts, you’ll find that in nearly every case we spend considerable time and effort discussing whether the placebo or sham control used was adequate, noting that, the better the sham controls, the less likely acupuncture studies are to have a positive result.
Some of the less clueless advocates of “complementary and alternative medicine” (CAM) seem to realize that much of what they do relies on placebo effects. As a result, they tend to argue that what they do is useful and good because it’s “harnessing the placebo effect” for therapeutic purpose. One problem that advocates of SBM (like those of us at SBM who have taken an interest in this topic) tend to have with this argument is that it has always been assumed that a good placebo requires on some level at least some deception of the patient by either saying or implying that he is receiving an active treatment or medicine of some kind. This, we have argued, is a major ethical problem in using placebos in patients, and advocates of placebo medicine appear to agree, because they frequently argue that placebo effects can be harnessed without deception. Indeed, just last week there was an example of this argument plastered all over multiple news outlets and blogs in the form of stories and posts with headlines and titles like:
Except for one, every one of these articles or blog posts discussing a new study in PLoS ONE that purports to have found that placebo effects can be elicited in irritable bowel syndrome (IBS) without deception buys completely into that very thesis. For example, here is an example, taken from the Reuters story about this study:
Placebos can help patients feel better, even if they are fully aware they are taking a sugar pill, researchers reported on Wednesday on an unusual experiment aimed to better understand the “placebo effect.”
Nearly 60 percent of patients with irritable bowel syndrome reported they felt better after knowingly taking placebos twice a day, compared to 35 percent of patients who did not get any new treatment, they report in the Public Library of Science journal PLoS ONE.
“Not only did we make it absolutely clear that these pills had no active ingredient and were made from inert substances, but we actually had ‘placebo’ printed on the bottle,” Ted Kaptchuk of Harvard Medical School and Beth Israel Deaconess Medical Center in Boston, who led the study, said in a statement.
I keep half an eye on the medicine displays in stores when I shop, and this year is the first time I have seen Oscillococcinum being sold. Airborne as been a standard for years, but Airborne has been joined by Oscillococcinum on the shelves. Dumb and dumber. It may be a bad case of confirmation bias, but it seems I am seeing more iocane powder, I mean oscillococcinum, at the stores.
On a recent podcast I was listening to one of the hosts suggested a homeopathic remedy for flu symptoms, and then specifically suggested osillococcinum. This is a technology podcast, the 404, and the hosts are certainly bright, educated people. Why would he suggest osillococcinum? Probably because he unaware of how oh so silly the product is.
On October 19, 2010, the FDA approved a long-awaited new drug, dabigatran, expected to replace warfarin (Coumadin) as a better way to prevent blood clots in susceptible patients. This provides an opportunity to re-visit several issues that we have addressed before, including Big Pharma tactics, drug approval by the FDA, deciding what is adequate evidence, applying science to clinical practice, and making individual health care decisions based on evidence that is sometimes incomplete.
Patients with atrial fibrillation, artificial heart valves, deep vein thrombosis, pulmonary embolism, antiphospholipid syndrome, and people undergoing certain types of surgery are at risk of blood clots, embolism, and stroke. They are currently being treated with rat poison. Warfarin (Coumadin) is an anticoagulant originally intended to kill rats. It inhibits the vitamin K dependent synthesis of several clotting factors. It saves human lives but is a mixed blessing. It takes several days to achieve therapeutic levels. Patients must be monitored with frequent blood tests to ensure that their prothrombin levels stay between an INR (international normalized ratio) of 2 and 3. When starting out, this means blood tests every couple of days. For some patients, dosage fluctuates and requires frequent adjustments; others can eventually drop down to a monthly blood test. Warfarin interacts with a long list of other drugs that raise or lower its blood levels. It interacts with many foods, and patients have to modify their diet. It can cause serious bleeding complications; while preventing thrombotic strokes it can cause hemorrhagic strokes. It is taken once daily. There is an antidote, vitamin K, that can reverse its effects promptly.
Warfarin is the 11th most prescribed drug in the US. Its benefits clearly outweigh its risks, but we wish the risks were fewer. We have yearned for a better option: something safer, something that would not require monitoring with blood tests, something that foods wouldn’t interfere with, something that would not interact with every other drug in the book. And now it seems we have it: a direct thrombin inhibitor called dabigatran.
Although I’m one of the few non-clinicians writing here at SBM, I think about clinical trials a great deal – especially this week.
First, our colleague, Dr. David Gorski, had a superb analysis and highly-commented post on The Atlantic story by David H. Freedman about the work of John Ioannadis – more accurately, on Freedman’s misinterpretation of Ioannadis’s work and Dr. Gorski’s comments. While too rich to distill to one line, Dr. Gorski’s post struck me in that we who study the scientific basis of medicine actually change our minds when new data become available. That is a GoodThing – I want my physician to guide my care based on the latest data that challenges or proves incorrect previously held assumptions. However, this concept is not well-appreciated in a society that speaks in absolutes (broadly, not just with regard to medicine), expecting benefits with no assumption of risk or sacrifice in reaping those benefits. Indeed, the fact that we change our minds, evolving and refining disease prevention and treatment approaches, is how science and medicine move forward.
Then, I had the opportunity to hear an excellent talk on pharmaceutical bioethics by Ross E. McKinney, Jr., MD, Director of the Trent Center for Humanities, Bioethics, and History of Medicine at Duke University School of Medicine. McKinney is a pediatrics infectious disease specialist who led and published landmark Phase I and Phase II trials zidovudine (AZT) for pediatric AIDS patients. While he continues working in this realm, McKinney also studies clinical research ethics, conflicts of interest, and informed consent. I was absolutely fascinated and refreshed by hearing from an expert who while describing and citing major ethical lapses in our system of drug development is also willing to propose solutions and do the hard thinking required for us to maximize the benefits we derive from pharmaceuticals while minimizing unethical behavior.
In my group practice, the Yale Medical Group, drug-company sponsored lunches and similar events have been banned. This is part of a trend, at least within academic medicine, to create some distance between physicians and pharmaceutical companies, or at least their marketing divisions. The justifications for this are several, and are all reasonable. One reason is the appearance of being too cozy, which compromises the role of academic physicians as independent experts.
But the primary reason is the belief that “detailing” by pharmaceutical sales representatives has a negative effect on the prescribing habits of physicians. There is reason to believe this may be the case because of cases of bad behavior on the part of pharmaceutical marketing divisions – ghost writing white papers, for example. The concern, backed by evidence, is that pharmaceutical companies introduce spin and bias into the information they provide to physicians, whether though CME, detailing, literature, or sponsored lectures. Even when the information itself is not massaged, it is cherry picked, so in the end physicians are not getting a thorough and unbiased assessment of the facts.
The FDA does heavily regulate the marketing of information about pharmaceuticals, but marketers are very clever about exploiting loopholes and seem to be one step ahead of the regulators.
On the other hand there are those who argue that physicians can handle access to information and they are equipped to take it with a grain of salt and put it into context. Certainly most physicians I speak to believe this about themselves. Further, information provided by pharmaceutical companies may actually improve prescribing habits if it makes physicians aware of new products on the market and new information about the drugs they prescribe. The information itself is FDA approved (or at least should be), even if it is selective and wrapped in spin.
Chelation is the provision of a substance to increase the body’s excretion of heavy metals. In poisoning situations (lead, aluminum, iron, etc.), chelation is medically necessary, objectively effective, and approved for use. But the same term has a completely different meaning in the alternative medicine universe, where proponents often believe heavy metal toxicity is the “one true cause” of disease, and chelation can undo microvascular inflammation, atherosclerosis, and even aging itself. From early days as an unproven treatment of coronary artery disease, its use has expanded to include autism, Alzheimer’s disease, cancer, and dozens of other diseases. Today, chelation is widely available. Regrettably, my own profession, pharmacy, facilitates this pseudoscience by manufacturing and selling chelation products.
Provoked urine tests are a common entry point to chelation therapy. Patients are given a product to provoke heavy metal excretion. The urine is tested and the patient is informed that they’re “toxic” and require chelation. Unfortunately, these results are meaningless and provide no evidence that chelation is medically necessary. But that’s the justification used for advocating a treatment regimen that will be useless at best and fatal at worst. A recent Medical Letter review concluded:
Medical Letter consultants believe that the use of chelation therapy in non-standard protocols for unsubstantiated indications should be discouraged. The results of provoked urine testing are not an acceptable basis for such treatment.
Providing chelation to patients isn’t a straightforward matter. It’s typically an intravenous infusion (though there are some oral products). Unless you’re part of the dubious TACT trial, which has administration centres across the United States and Canada, there are few products commercially available. For example, edetate calcium disodium (EDTA) is approved for sale in the United States but not Canada. Edetate disodium (also called EDTA) is not approved for sale in either country. But these products are widely available: they’re manufactured by pharmacists in pharmacies.