Should you take expiry dates seriously?

Is is safe to take expired drugs? Are they still effective? Consider this scenario:

You’re in good health and take no prescription drugs. You use the following remedies occasionally:

• Excedrin for the rare migraine
• Arnica 30CH for bumps and bruises
• Echinacea capsules, when you feel a cold coming on

Today you look in your cupboard, and notice all three products expired last year. Would you still consider taking any of them? Why or why not?

Your answer is probably influenced by a number of factors, including perceptions of risk and benefit. I’ve encountered patients who believe that drugs are less active as they near the expiration date, and others who see expiry dates solely as marketing ploy from Big Pharma. Few understand  how they’re calculated.

Over the past few months I’ve written several posts on different aspects of drug development and testing, including drug interactions, fillers and excipients in drug products, the equivalence testing of generic drugs, and the management of drug allergies. I’ve done this for two reasons. The first is to develop a resource for common questions and misconceptions about the mechanics of modern medicines. The second, less obvious reason for these posts has been to illustrate the serious credibility gaps with CAM (so-called “complementary” and “alternative”) therapies. Largely because of lax regulatory frameworks in the USA and Canada, the CAM industry has ballooned into a multi-billion dollar market without answering basic questions that should be asked of any supplement or drug, “alternative” or otherwise. What’s not well known to consumers, but is glaringly obvious to science-based health practitioners, is that CAM largely ignores issues of pharmacology: understanding how a chemical substance, once consumed, behaves in the body. It’s critical to scientific medicine, but an unnecessary step for CAM, where there’s no need to determine if a product has a beneficial biological effect before selling it. Fundamental tests in medicine, like the identification and isolation of an active ingredient, or understanding dose-effect relationships, are simply ignored. Science-advocates are regularly accused of being biased, to which I plead guilty. I have a reality bias, and don’t believe that magical thinking and pseudoscience form the basis of credible medicine, or pharmacy practice. And this bias is equally jarring when it comes to considering expiry dates for products: real drugs, and also CAM.

Gold mine or dumpster dive? A closer look at adverse event reports

All informed health decisions are based on an evaluation of risks and benefits. Nothing is without risk. Drugs can provide an enormous benefit, but they all have the potential to harm. Whether it’s to guide therapy choices or to ensure patients are aware of the risks of their prescription drugs, I spend a lot of time discussing the potential negative consequences of treatments. It’s part of my dialogue with consumers: You cannot have an effect without the possibility of an adverse effect. And even when used in a science-based way, there is always the possibility of a drug causing either predictable or idiosyncratic harm.

An “adverse event” is an undesirable outcome related to the provision of healthcare. It may be a natural consequence of the underlying illness, or it could be related to a treatment provided. The use of the term “event” is deliberate, as it does not imply a cause: it is simply associated with an intervention. The term “adverse reaction,” or more specifically “adverse drug reaction,” is used where a causal relationship is strongly suspected. Not all adverse events can be be causally linked to health interventions. Consequently, many adverse events associated with drug treatments can only be considered “suspected” adverse drug reactions until more information emerges to suggest the relationship is likely to be true.

Correlation fallacies can be hard to identify, even for health professionals. You take a drug (or, say, are given a vaccine). Soon after, some event occurs. Was the event caused by the treatment? It’s one of the most common questions I receive: “Does drug ‘X’ cause reaction ‘Y’?” We know correlation doesn’t equal causation. But we can do better than dismissing the relationship as anecdotal, as it could be real. Consider an adverse event that is a believed to be related to drug therapy:

Weekend Reading

Posts, columns, and other reading from the past several weeks that I enjoyed – and you may, too.

Wobenzym N: A closer look at “systemic” enzyme therapy

One of the recurrent themes in alternative medicine is the practice of simplifying complex medical conditions, and then offering up equally simple solutions which are positioned as still being within the realm of science. This approach allows the practitioner to ignore all of the complexity and difficulty of practicing real medicine, yet offer nostrums that, on first glance, can sound legitimate. Science-y, even.

I’ve discussed this before in non-science-based approaches to food intolerances, whether it’s using clinically useless IgG blood tests, or declaring the universal dietary enemy to be gluten. David Gorski elaborated on the same theme recently at Science-Based Medicine in the context of cancer treatment, contrasting the simplistic views of alternative medicine purveyors with the facts of cancer research. Cancer is stunningly complex – each of the hundreds of different variants of the disease. I’m always amazed when I speak with oncologists about how treatment regimens have been established. They describe how the results of dozens of clinical trials, led by different trial groups around the world have each contributed to establishing the current “best” regimens for each cancer: the appropriate drugs, doses, intervals and treatment intensities. Good evidence speaks all languages, and as new data emerges, practices change quickly to build upon whatever new evidence has emerged. The complexity of treatments continue to increase. Overlay the genetic and genomic complexity David described, and you get a sense of the challenges (and opportunities) cancer researchers face in order for science continue to improve outcomes for patients with cancer.

So it’s a bit of a shock when you shift your attention to the alternative medicine “literature”, where simple solutions abound. One that’s popular among patients I speak with, particularly those with European backgrounds, is the use of what are called systemic enzymes – enzymes, consumed orally, with the intent of whole-body effects. These products are not used as part of “conventional” medicine but are popular supplements recommended by alternative practitioners. I was recently asked about a product called Wobenzym N, a product with German roots which is advertised with the following claims [PDF]:

Dilutions of Grandeur: It’s World Homeopathy Awareness Week

Homeopathy is nonreturnable

April 10-16 is World Homeopathy Awareness Week, dedicated by homeopaths to promote an awareness and understanding of homeopathy. I think that’s an excellent idea. Homeopathy is an elaborate placebo system of sugar pills. It doesn’t work. It cannot work.  If it did, physics, biochemistry and pharmacology as pharmacists know it would be false. Of all alternative medicine, homeopathy is the most implausible of them all.  Based on the absurd notion of “like cures like” (which is sympathetic magic, not science), proponents of homeopathy believe that any substance can be an effective remedy if it’s diluted enough: raccoon fur, the sunlight reflecting off Saturn, even pieces of the Berlin Wall are all part of the homeopathic pharmacopeia.  And when I say dilute, I mean dilute. The 30C “potency” is common – it’s a ratio of 10^-60.  You would have to give two billion doses per second, to six billion people, for 4 billion years, to deliver a single molecule of the original material. So remedies are effectively and mathematically inert – they are pure placebo. Not surprisingly, there is no persuasive medical evidence that these products have therapeutic effects.

Homeopathy could be written off as a harmless nostrum if it caused no harm. But that’s not the case. Homeopathy can delay patients from seeking science-based treatments. Consumers buy products thinking they are effective, when they have no active ingredients. When they’re on pharmacy shelves, it’s unfair and unethical to expect patients to be able to able to distinguish real drugs from placebos.  A paper from Michael Baum and Edzard Ernst, writing in the American Journal of Medicine in 2009 made this statement about homeopathy:

It is considered unethical for modern medical practitioners to sink to this kind of deception that denies the patient his or her autonomy. Secondly, by opening the door to irrational medicine alongside evidence-based medicine, we are poisoning the minds of the public. Finally, if we don’t put a brake on the increasing self-confidence of the homeopathic establishment, they will cease to limit their attention to self-limiting or nonspecific maladies.

Baum and Ernst were correct in their evaluation, as you see in this roundup of homeopathic issues from around the world:

Antivax 101: Tactics and Tropes of the Antivaccine Movement

This is the first of a series of posts adapting a presentation made at The Ontario Public Health Convention in April, 2011. The presentation, “Fighting in the Trenches: Countering Anti-Vaccine Sentiment with Social Media” was a panel discussion from Scott Gavura and Kimberly Hébert:

One of the best parts of the infectious disease outbreak movie Contagion was the decision to include an antivaccinationist, conspiracy-minded, alternative health advocate, played by Jude Law. Law gave a character-perfect performance of someone intent on deliberately and selfishly thwarting public health advice, putting lives at risk as a consequence. Sadly, the writers didn’t have to look far for real world examples: It’s hard to forget “Health Ranger” Mike Adams’s paranoid music video produced in 2009, at the height of H1N1, when he decided to put every antivaccine argument into one performance.

But the Health Ranger is just the current manifestation of antivaccine sentiment which has been around since vaccines were invented:

When a theory has been confirmed so completely by facts as has the proposition that vaccination effectually performed will prevent an individual from contracting small-pox, or at least so fundamentally modify the disease that it is no longer a serious malady, there is in many minds a natural distaste to fight the battle again or to be constantly defending the position against the attacks of ill-informed or prejudiced persons.

- British Medical Journal, July 24, 1897

But this battle is still being fought, after over 100 years of immunization, and over two dozen diseases becoming vaccine-preventable. The anti-vaccine movement is a real movement, and it’s doing what it can to create fear, uncertainty and doubt regarding public health messaging. There is evidence that antivaccinationists can influence vaccination decisions. The arrival of social media over the past decade means there’s the need for public health advocates to adapt their messaging to this new medium. What seems clear is that “traditional” public health tactics, with warnings and arguments from authority, are dwindling in their effectiveness. All aspects of medicine are moving towards models of shared decision-making. This is an overdue change, and it’s been facilitated by the widespread availability of health information. Information is no longer hidden from public access. Want the approved product monograph for a vaccine? It’s available online. Even the primary literature is becoming more freely accessible.

Unfortunately, the power of the Web 2.0 and social media has made it easier for antivaccinationists to foster antivaccine fears and sentiment. In order to combat this misinformation, the movement’s tactics and tropes must be understood, so they can be called out.

Anti-anti-vax: Getting to the gist

I’m currently putting the finishing touches on a presentation for the The Ontario Public Health Convention next week, where I’ll be speaking, with occupational therapist Kim Hébert, about the anti-vaccine movement and social media (SM): how antivaccine advocates use it, and the challenges and opportunities for public health advocates. I’m pleased to see Seth Mnookin, author of The Panic Virus, is one of the keynote speakers – his perspective will be valuable for the public health crowd which has traditionally relied on fairly static “key messages” for disseminating information on vaccine safety and effectiveness. The panel discussion of which I am a part will be an examination of challenges and opportunities presented to public health advocacy, and particularly vaccine advocacy, in a Web 2.o environment. What seems clear is that the old public health channels don’t cut it anymore: these methods are distant and insufficient to address the wide and rapid spread of misinformation in an era of social media. We all remember the anxiety over H1N1 just a few years ago – and judging by the poor uptake of the vaccine, it seemed the anti-vaccine movement had some success in propagating fear, uncertainty, and doubt. I’d almost forgotten about this chestnut from the Health Ranger himself:

Is gluten the new Candida?

Much of the therapeutics I was taught as part of my pharmacy degree is now of historical interest only. New evidence emerges, and clinical practice change. New treatments replace old ones – sometimes because they’re demonstrably better, and sometimes because marketing trumps evidence. The same changes occurs in the over-the-counter section of the pharmacy, but it’s here marketing seems to completely dominate. There continues to be no lack of interest in vitamin supplements, despite a growing body of evidence that suggests either no benefit, or possible harm, with many products. Yet it’s the perception that these products are beneficial seem to be seem to continue to drive sales. Nowhere is this more apparent than in areas where it’s felt medical needs are not being met. I covered one aspect a few weeks ago in a post on IgG food intolerance blood tests which are clinically useless but sold widely. The diagnosis of celiac disease came up in the comments, which merits a more thorough discussion: particularly, the growing fears over gluten consumption. It reminds me of another dietary fad that seems to have peaked and faded: the fear of Candida.

It wasn’t until I left pharmacy school and started speaking with real patients that I learned we are all filled with Candida – yeast. Most chronic diseases could be traced back to candida, I was told. And it wasn’t just the customers who believed it. One particular pharmacy sold several different kits that purported to eliminate yeast in the body. But these didn’t contain antifungal drugs – most were combinations of laxative and purgatives, combined with psyllium and bentonite clay, all promising to sponge up toxins and candida and restore you to an Enhanced State of Wellness™. There was a strict diet to be followed, too: No sugar, no bread – anything it was thought the yeast would consume. While you can still find these kits for sale, the enthusiasm for them seems to have waned. Whether consumers have caught on that these kits are useless, or have abandoned them because they don’t actually treat any underlying medical issues, isn’t clear.

The trend (which admittedly is hard to quantify) seems to have shifted, now that there’s a new dietary orthodoxy to question. Yeast is out. The real enemy is gluten: consume it at your own risk. There’s a growing demand for gluten labeling, and food producers are bringing out an expanding array of gluten-free (GF) foods. This is fantastic news for those with celiac disease, an immune reaction to gluten, where total gluten avoidance is essential. Only in the past decade or so has the true prevalence of celiac disease has become clear: about 1 in 100 have the disease. With the more frequent diagnosis of celiac disease, the awareness of gluten, and the harm it can cause to some, has soared. But going gluten free isn’t just for those with celiac disease. Tennis star Novak Djokovic doesn’t have celiac disease, but went on a GF diet. Headlines like “Djokovic switched to gluten-free diet, now he’s unstoppable on court” followed. Among children, there’s the pervasive but unfounded linkage of gluten consumption with autism, popularized by Jenny McCarthy and others. Even in the absence of any undesirable symptoms, gluten is being perceived as something to be avoided.

Food intolerance blood tests have no place in the pharmacy

Imagine your pharmacy features a blood pressure measurement device. It has never worked correctly. Sometimes it give incorrect high results, suggesting hypertension. In other patients it misses hypertension completely. You’ve been advised by hypertension experts that this particular model isn’t accurate and shouldn’t be offered to consumers. Despite this, you continue to promote it to your patients, and you use the test results to recommend supplements to treat conditions that may or may not not exist.

Does this meet the professional standards expected for pharmacists? From an ethical perspective, does it respect patient autonomy?  My sense is that consumers, ethicists, regulators, and other health professionals would say “no”. Pharmacists have an ethical and professional responsibility to base advice on the best scientific evidence – in this case, to ensure that a service being offered is reliable, accurate, and relevant for making health decisions.

That’s why I’m surprised to see Canadian and American pharmacies are now selling IgG food intolerance tests. Because if you agree that knowingly offering faulty blood pressure measurement tests is unacceptable, you should have just as much concern about food intolerance blood tests. These tests have been available for some time in the United Kingdom. Now they’re in North America. Rexall, the Canadian pharmacy chain, recently started selling the “Hemocode” test which is purported to test for 250 food intolerances:

You can’t cleanse away a smoking addiction

For every challenging medical issue, there’s a quick fix that exists in alternative medicine – and disappointingly, sometimes it’s sitting on a pharmacy’s shelf. This week I spotted an advertisement targeting an addiction, one that is the single biggest preventable cause of death worldwide: smoking. We associate smoking with lung cancer, but smoking kills in two other ways as well: cardiovascular disease, and chronic obstructive pulmonary disease. Tobacco kills 6 million people per year, causing hundreds of billions of dollars worth of pain, suffering, and economic damage. [PDF]  Stopping smoking reduces the risk of dying – the damage lessens over time in those that quit completely.

Despite the known harms, quitting smoking is very difficult: 70% of active smokers say that they want to quit, 40% tried to quit over the last year, yet only 3-7% are smoke free after one year of quitting. With support and treatment, abstinence rates can climb to 30%+ (at best) but few seek medical attention and support. Some may be enticed by advertisements like the one I spotted. The website and ad have the same message: