This transcript has been edited for clarity.
Matthew F. Watto, MD: Welcome back. I'm Dr Matthew Watto, and this is the Curbsiders, here with my good friend, Dr Paul Williams. Paul, can you tell us about today's video?
Paul N. Williams, MD: We are the internal medicine podcast, and this video is a recap of one of our podcast episodes. We use expert interviews to bring you clinical pearls and practice-changing knowledge. Tonight we had the pleasure of speaking with Dr Douglas Paauw about medical myths, and we'd like to share some of our favorite practice-changing takeaways from that podcast. Matt, what did you learn?
Watto: Takeaway number one is a recurring theme that we've visited before under multiple different names. When these myths are created, and people incorporate them into practice even after the evidence is available, it can take decades for the practice to stop. I don't know if it's stubbornness, inertia, or local culture, but it takes forever to eliminate a practice.
Williams: You're just so happy to have these facts in your back pocket, to bust out when you're teaching, that it hurts to lose them. One of the myths we discussed was the so-called disulfiram reaction that happens if you combine metronidazole and alcohol. It's something I have taught a lot; it's one of the things I'm always happy to remind my residents of. If you take metronidazole and drink alcohol on top of it, you will have the same reaction as if you took Antabuse, the medication that makes you sick if you drink alcohol. But it turns out that there is little to no evidence to support that.
In fact, for one study, they took a group of medical students and got them drunk. The students then took metronidazole or placebo for 5 days and were asked to report any symptoms of this reaction. It turns out that none of them had symptoms consistent with the disulfiram reaction. Even though it sounds great and mechanistically makes a lot of sense, it's probably not actually true, and patients are probably safe to drink when taking metronidazole, although I wouldn't encourage it.
Watto: And these studies are at least 8-20 years old. But finally there is a rumor that the new STI guidelines are going to drop the precaution about metronidazole and alcohol causing a disulfiram reaction. We're making some progress.
Another myth, and this is my favorite because I think I've made some mistakes or missed this diagnosis, is that sinus headaches are often attributed to symptoms of headache and nasal congestion, and actually what's happening is that these are migraine headaches masquerading as sinus symptoms. Among people who are diagnosed with sinus headaches, 88%-90% respond to migraine therapy, and their headaches could be called "migrainous headaches" by the American Headache Society criteria.
Don't miss that. If you have a patient who is telling you they have chronic headaches and they attribute them to sinus headaches, with sinus symptoms, pressure, and nasal congestion, that could be a migraine headache and it might be as simple as treating the patient for migraine headaches. That was a huge revelation for me.
Williams: That was an eye opener for me, too. I can think of a couple of cases that I wish I could go back and do over, with that knowledge.
The other topic I'd like to talk about is expired medications. It cuts both ways. It's not unusual to hear patients say, "I had this medication lying around so I took some of it, and I felt better." Internally, I die a little bit. Conversely, we have patients who worry about a medication that's 3 days past its expiration date. "Will it kill me?"
There's a bit of anxiety on both sides. We talked about a couple of studies that looked at this. I'm going to read a line from one study. "Eight long-expired medications with 15 active ingredients were discovered in a retail pharmacy in their original unopened containers." Someone found some old drugs and said, "We need to study these." And they did. They looked at potency of the expired drugs, and there were only a few — aspirin among them — that actually degraded over time. The vast majority maintained their potency at more than 90%.
For the most part, I certainly wouldn't encourage patients to take decades-old medications. On the other hand, it's reassuring that most of these medications retain their potency a little past their expiration dates, so you shouldn't necessarily throw them away after you've crossed that threshold.
Watto: Along these lines, there are a couple of things I'd like to mention. Dr Paauw told us that eye drops are so expensive by weight that they are more valuable than gold. They looked at a study with eye drops that were about 12 weeks beyond the expiration date and found that even if they were open, they were still potent. So don't throw away eye drops; they're worth their weight in gold.
Epinephrine autoinjectors (EpiPen) maintained their potency many months past their expiration date. Paauw suggested not using an expired pen as your primary EpiPen, but you can stash the expired EpiPens in various locations, such as your office. Keep your primary unexpired EpiPen with you, and keep some of those recently expired EpiPens around too, because they will have at least some effect.
These are all really useful and practical tips. That's all for now; thank you for watching.
Click to hear the full episode Medical Myths: Challenge Dogma With Dr Douglas Paauw, or find the Curbsiders podcasts on iTunes.
The Curbsiders is a national network of students, residents, and clinician educators from across the country, representing 15 different institutions. They "curbside" experts to deconstruct various topics in the world of medicine to provide listeners with clinical pearls, practice-changing knowledge, and bad puns. Learn more about their contributors and follow them on Twitter.
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Cite this: Matthew F. Watto, Paul N. Williams. Medical Myths: Drunk Med Students, Masquerading Migraines, and More - Medscape - Aug 07, 2020.