Does Tamiflu have any meaningful effects on the prevention or treatment of influenza? Considering the drug’s been on the market for almost 15 years, and is widely used, you should expect this question has been answered after 15 flu seasons. Answering this question from a science-based perspective requires three steps: Consider prior probability, be systematic in the approach, and get all the data. It’s the third step that’s been (until now) impossible with Tamiflu: Some data was unpublished. In general, there’s good evidence to show that negative studies are less likely to be published than positive studies. Unless unpublished studies are included, systematic reviews are more likely to miss negative data, which means there’s the risk of bias in favor of an intervention.
The absence of a full data set on Tamiflu (oseltamivir) and the other neuraminidase inhibitor Relenza (zanamivir) became a rallying point for BMJ and the AllTrials campaign, which seeks to enhance the transparency and accessibility of clinical trials data by challenging trial investigators to make all evidence freely available. (Reforming and enhancing access to trial data was one of the most essential changes recommended by Ben Goldacre in his book, Bad Pharma.) In 2009, Tamiflu’s manufacturer, Hoffman-La Roche committed to making the Tamiflu data set available to investigators. Now after four years of back-and-forth between BMJ, investigators, and Roche, the full clinical trials data set has been made freely available. An updated systematic review was published today in BMJ (formerly The British Medical Journal), entitled “Oseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments.” This will be a short post covering the highlights. As the entire study and accompanying data are freely available, I’ll await continued discussion in the comments. (more…)
“Will Tylenol harm my baby?”
Pharmacists are among the most accessible of health professionals, and so we receive a lot of questions from the public. No appointment required, and the advice is free. Among the most frequent sources of questions are women seeking advice on drug use in pregnancy. This is an area where some health professionals are reluctant to tread. Some prefer to redirect all of these questions to physicians. But physicians are not always easily accessible, and few want to make an appointment just to ask what appears to be a simple question: Is it safe, or not? Admittedly, addressing questions about drug use in pregnancy can be challenging. There are no randomized controlled trials we can look to — there’s only messier, less definitive data. Our responses are filled with cautious hedging about risk and benefit, describing what we know (and don’t know) about fetal effects. In the pharmacy, one of the most common questions from pregnant women is about the use of acetaminophen (aka paracetamol aka APAP), more commonly known by the brand name Tylenol. Google “Tylenol and pregnancy” and you get 4.8 million results. Which source should you trust? (more…)
I glanced at my pharmacy license recently, and noticed I became a licensed pharmacist almost exactly twenty years ago. Two decades seems like a long time to do pretty much anything, yet I can still vividly recall some of the patients I encountered early in my career, working evenings in a retail pharmacy that drew heavily on the alternative medicine crowd. It was the first pharmacy I’d ever seen that sold products like homeopathy, detox kits, salt lamps, ear candles, and magnetic foot pads. And the customers were just as unorthodox. There were some that told me they manipulated their own pH, and others that insisted any prescription drug was designed to kill. And there was a huge clientele that relied on the pharmacy for their “bioidentical” hormones. It was an instructive learning experience, as it was as far from the science of pharmacy school as you could expect to find in a place that still called itself a pharmacy. One of the really interesting aspects of that pharmacy was the enormous supply of vitamins and supplements for sale. It stretched over multiple aisles and even back into where the drugs were kept, as there were some brands kept behind the counter. This wasn’t for any regulatory reason – it was because these were the “naturopathic” supply, the brands often recommended by naturopaths. In order for this pharmacy to sell them they had to keep the products behind the counter, presumably to grant these supplements a veneer of medical legitimacy. After all, they were “special”, and had the prices to prove it. (more…)
Diets fail. Not just often, but almost always—90% of the time. If diets worked we wouldn’t have a worldwide obesity problem. And obesity is a problem that needs to be solved. The prevalence of obesity has doubled since 1980. As a public health issue, there are few determinants of illness that are more destructive, as obesity contributes to the growing rates of diabetes, heart disease, and even cancer. There’s no “one true cause” of all illness, but obesity comes pretty close. When people ask me for the single most important thing they can do for their health, my advice (after quitting smoking) is to (1) ensure you keep your weight under control and (2) exercise in any way possible.
Despite its tremendous impact on health, I’ve only blogged about obesity in an indirect way—by pointing out what doesn’t work. Dr. Oz is my perpetual source of bad health information with his regular promotion of bogus “weight loss” supplements like the green coffee bean “miracle”. I’ve also criticized eating programs like the fads of “Eating Clean”, gluten “intolerance”, or harmful diet delusions like “detox”. It’s the typical skeptical science blogger approach—spot pseudoscience, debunk it, and hope you did something good. But none of my posts have focused on what one should do—just what you shouldn’t. Weekly SBM contributor Dr. Mark Crislip recently commented that what we (SBM) support manifests in what we oppose. He’s right, because that’s the easy approach. Using the principles of science-based medicine, there’s an awful lot to oppose in the current writing and popular opinion on how to treat obesity. And my professional advice in the role of a pharmacist has been limited to steering people away from supplements, and then giving some basic advice about dietary planning. Anecdotes and platitudes. I admit that I’ve told patients to “eat less and exercise more”.
One of the encouraging shifts I’ve seen in health journalism over the past few years is the growing recognition that antivaccine sentiment is antiscientific at its core, and doesn’t justify false “balance” in the media. There’s no reason to give credibility to the antivaccine argument when their positions are built on a selection of discredited and debunked tropes. This move away from false balance and towards a more accurate reflection of the evidence seems to have started with the decline and disgrace of Andrew Wakefield and his MMR fraud. And there is now no question that antivaccine sentiment has a body count: Simply look at the resurgence of preventable communicable disease. Today, antivaccinationists are increasingly recognized for what they are – threats to public health. It seems less common today (versus just 5 years ago) that strident antivaccine voices are given either air time or credibility in the media.
But false balance on topics like influenza can occur without giving a voice to groups like antivaccinationists. A more subtle technique to shift perceptions is both widespread and hard to detect, unless you’re aware of it: the naturalistic fallacy, known more accurately as the appeal to nature. In short, it means “It’s natural so it’s good” with the converse being “unnatural is bad.” In general, the term “natural” has a positive perception, so calling a product (or a health intervention) “natural” is implying goodness. The appeal to nature is so common that you may not even recognize it as a logical fallacy. Unnatural can be good, and natural can be bad: Eyeglasses are unnatural. And cyanide is natural. Natural doesn’t mean safe or effective. But the appeal to nature is powerful, and it’s even persuasive to governments. If we believe that health interventions and treatments should be evaluated on their merits, rather than whether or not they’re “natural”, then decisions to regulate “natural” products differently than the “unnatural” ones (like drugs) makes little sense. Yet the Dietary Supplement Health and Education Act was a legislative appeal to nature, introducing a different regulatory and safety standard for a group of products while drawing a fallacious distinction with “unnatural” products like drugs. Canada fell for the appeal to nature too: It has the Natural Health Products Regulations which entrenched a lowered bar for efficacy and safety for anything a manufacturer can demonstrate is somehow “natural”. (more…)
One of these things is not like the other
Treating a fever with medication like Advil or Tylenol is reflex action when we come down with colds and influenza. But could treating fevers actually worsen an illness and contribute to its spread in the population? That’s the impression you may have gained from the headlines and press last week, where antipyretics (fever-reducing medications) were described as some type of “anti-vaccine”:
Fever-reducing meds encourage spread of flu: McMaster report
Taking over-the-counter flu medication to cut your fever might help you feel better, but it might not be so good for the people you come into contact with.
When it comes to fever, your mother really did know what’s best
Who would have thought that the simple giving of a fever reducing agent, to either one of our family members or ourselves before we go off to school or work, may inadvertently lead to the death of someone that we see that day?
Use of fever-reducing drugs may lead to tens of thousands more influenza cases
The bottom line is that fever suppression increases the number of annual cases by approximately five per cent, corresponding to more than 1,000 additional deaths from influenza in a typical year across North America.
It’s the time of year where if you’re not sick, someone you know probably is. The influenza season in the Northern hemisphere started out slowly, but seems to be accelerating and hasn’t peaked yet. Add that to cold viruses circulating, and you get the peak purchasing period for cough and cold remedies. John Snyder gave a nice summary of the evidence base for the common treatments a few weeks ago. In short, despite all the advertising, there is little evidence to suggest that most of the “tried and true” products we’ve used for decades have any effect on our symptoms. One of the most sensible developments that’s occurred over the past few years has been the discontinuation or relabeling (depending on your country) of cough and cold products for children. The rationale to pull these products is compelling: Cough and cold remedies have a long history of use, and were sold without prescriptions before current regulatory standards were in place. They were effectively grandfathered onto the marketplace. When it comes to their use in children, the data are even more limited. There are few published trials and the results are complicated by different age groups, irregular dosing, lack of placebo control, and very small patient numbers. What’s even harder to believe was that doses were based mainly on expert opinion, not data, and generally didn’t consider that children don’t handle drugs the way adults do. So why withdraw them from pediatric use, but not adult use? Like most regulation, it comes down to risk and benefit. Both are troubling for pediatric use. (more…)
Note to SBM’s regular readers: Today’s post revisits some older material you may have seen before. Happy New Year!
New Year, New You, right? 2014 is the year you’re finally going to get serious about your health. You’re winding down from a week (or more) of celebrations and parties. You’re pretty much recovered from New Year’s Eve by now. It’s time to make some resolutions. Conveniently, there is no shortage of solutions being advertised to absolve you of your sins while overhauling your body and soul for 2014: What you need to do is “detox”. You’ll see the detox kits at your local Whole Foods (or even your local pharmacy). Books, boxes or bottles, with some combination of “detox”, “cleanse” or “flush” in the product name. Supplements, tea, homeopathy, coffee enemas, ear candles, and footbaths all promise detoxification. The advertising suggests you’ll gain a renewed body and better health – it’s only seven days and $49.95 away. Or try to cleanse yourself with food alone: Dr. Oz is hyping his Holiday Detox plan. Bon Appetit is featuring their 2014 Food Lover’s Cleanse. Or what about that old standby, the “Master Cleanse”? It’s the New Year – wouldn’t a purification from your sins of 2013 be a good idea to start the year? After all, the local naturopath offers complete detoxification protocols, including vitamin drips and chelation. There must be something to it, right? (more…)
If scientific evidence guides our health decisions, we will look back at the vitamin craze of the last few decades with disbelief. Indiscriminate use is, in most cases, probably useless and potentially harmful. We are collectively throwing away billions of dollars into supplements, chasing the idea of benefits that have never materialized. Multivitamins are marketed with a veneer of science but that image is a mirage – rigorous testing doesn’t support the health claims. But I don’t think the routine use of vitamins will disappear anytime soon. It’s a skillfully-marketed panacea that about half of us buy into.
Not all vitamin and mineral supplementation is useless. They can be used appropriately, when our decisions are informed by scientific evidence: Folic acid prevents neural tube defects in the developing fetus. Vitamin B12 can reverse anemia. Vitamin D is recommended for breastfeeding babies to prevent deficiency. Vitamin K injections in newborns prevent potentially catastrophic bleeding events. But the most common reason for taking vitamins isn’t a clear need, but rather our desire to “improve overall health”. It’s deemed “primary prevention” – the belief that we’re just filling in the gaps in our diet. Others may believe that if vitamins are good, then more vitamins must be better. And there is no debate that we need dietary vitamins to live. The case for indiscriminate supplementation, however, has never been established. We’ve been led to believe, through very effective marketing, that taking vitamins is beneficial to our overall health – even if our health status is reasonably good. So if supplements truly provide real benefits, then we should be able to verify this claim by studying health effects in populations of people that consume vitamins for years at a time. Those studies have been done. Different endpoints, different study populations, and different combinations of vitamins. The evidence is clear. Routine multivitamin supplementation doesn’t offer any meaningful health benefits. The parrot is dead. (more…)
Once again, it’s influenza season. The vaccine clinics are open, and the hysterical posts about the vaccine’s danger are appearing in social media. There’s familiarity to all of this, but also a big new change – at least in Canada, where I am. Pharmacists can now administer the vaccine. And it’s completely free to anyone in Ontario (where I am), so the barriers to obtaining the vaccine are pretty much eliminated. There’s no longer a need to drag your kids to their family doctor or line up at a public health clinic. Anyone can walk into a pharmacy, show their health card, and walk out minutes later, vaccinated. It’s another enabling change that may help improve immunization rates, as uptake rates in the population remain modest.
This year’s flu season is (as of week 47) fairly quiet. Google Flu trends suggests a fairly typical picture, nothing like what we saw in 2009/10, the year of H1N1. My city’s influenza tracker reports only a dozen cases so far this season. Many of us will get our flu shot, continue with our lives, and not think about the flu until next season’s announcements. That’s the hope, anyway. Influenza can kill, and in its more virulent forms, is devastatingly deadly. The worst case scenario (so far) is almost unimaginable today. In 1918/19 an influenza pandemic killed 50 million people worldwide (5% of the population). So among public health professionals, that worry about the next wave is always present. Much has been written at this blog <plug>nicely compiled in the SBM ebook,</plug> on the efficacy and safety of the flu vaccine. In short, the vaccine is effective for both individual and population-level protection, but only modestly so, and its effectiveness varies based on its match with circulating strains. And despite widespread use for decades, there are frustrating limitations with the current vaccine beyond efficacy, including the need to repeat the shot annually. Someone said something about “going to battle with the army you have”. (I thought it was Crislip but he was quoting Rumsfeld.) The quote is apt. It’s not a perfect vaccine, but it does offer protection – if not directly to you, then indirectly to those at greater risk of infection. Hospitals and health facilities have been criticized for demanding health professionals either get the vaccine or wear a mask – and the arguments against vaccination are losing. But even the strongest advocates of influenza vaccine will acknowledge its limitations, which perhaps contributes to the understandable perception that there is more that could be done- beyond reasonable and effective precautions like handwashing and hygiene. (more…)