Transcription
Hey guys, it's Medicosis Perfection. We're continuing our series about bleeding and coagulation. In the previous video, we started talking about acetyl salicylic acid. Today, we'll talk about the medical, or the clinical uses—also known as indications—of acetylsalicylic acid, the wonder drug. With that being said, now let's get started. [Music]
It's part of my series about bleeding and coagulation. Please watch these videos, especially on the arachidonic acid pathway, because aspirin is all about inhibiting the cyclooxygenase in the arachidonic acid pathway. As you know, acetylsalicylic acid, aka aspirin (and type it in little a, ng), is an antibiotic and anti-inflammatory, one of the non-steroidals from the willow tree. And I've told you the difference between small a and big A aspirin. The mechanism of action irreversibly inhibits the cyclooxygenase. How does it inhibit it? If it's called acetyl salicylic acid, it will cause inactivation of this enzyme. Now it's inhibited; no thromboxane A2, no platelet aggregation. When there is no platelet aggregation (primary hemostasis), there is no blood coagulation (secondary hemostasis). Because if one causes two, and if you inhibit one, you don't get two.
Does aspirin inhibit cyclooxygenase 1 or cyclooxygenase 2? The answer is both. The arachidonic acid pathway: aspirin works by inhibiting the cyclooxygenase. When there is no cyclooxygenase, there is no thromboxane A2. When there is no thromboxane A2, there's no vasoconstriction, and there is no platelet aggregation. How about the prostacyclin? Now watch my previous video, and I've discussed prostacyclin and the aspirin effect on it. Why is aspirin bad for asthmatics? Because if arachidonic acid is not going to be converted into prostaglandin G2, thanks to the cyclooxygenase inhibition, all of the arachidonic acid will be converted into leukotrienes, which make the life of asthma patients hell.
Does aspirin inhibit cyclooxygenase 1 or cyclooxygenase 2? The answer is both. Is aspirin antiplatelet because it inhibits cyclooxygenase 1 or cyclooxygenase 2? The answer is cyclooxygenase 1, because only cyclooxygenase 1 leads to thromboxane A2, which causes platelet aggregation. I can ask you a third question: Is aspirin bad for your stomach because of inhibition of cyclooxygenase 1 or cyclooxygenase 2? The answer is COX 1. How do you eliminate aspirin from your body? It's not the juice cleanser; it's called zero-order elimination, and I've talked about it in the previous video.
Clinical uses of aspirin: antiplatelet, analgesic, antibiotic, anti-inflammatory. First, let's talk about antiplatelet: prevents myocardial infarction and the recurrence of myocardial infarction. Great. How? Because it inhibits platelets. When there are no platelets, there is no blood coagulation. Good. When you inhibit primary hemostasis, you don't get to have secondary hemostasis. Acute coronary syndrome, which is an umbrella term that includes—are you ready?—unstable angina, non-STEMI (which stands for non-ST elevation myocardial infarction, or no ST elevation). Then we have the STEMI (ST elevation myocardial infarction). Collectively, we call them acute coronary syndrome, because we love to classify stuff; that's what science is all about.
Prophylactic for atrial arrhythmias, such as atrial fibrillation (A-fib). What happens in atrial fibrillation is your heart is supposed to pump blood; in atrial fibrillation, your atrium just tickles the blood instead of pumping it, which is crazy. Why? Because when you don't pump blood, blood will stagnate—called blood stasis—and, according to this nice guy called Rudolph Virchow from Germany, blood stasis is one of Virchow's triad, which will lead to—yes, you guys said it—blood coagulation. So atrial fibrillation can lead to blood clots, so give aspirin to prevent that.
Back to acute coronary syndrome: we give TPA plus heparin plus aspirin—called combination therapy—because you thought that only McDonald's had combos. Doctors have combos as well; except our combos are very expensive. Diabetic stroke: ischemic stroke, not the hemorrhagic stroke. Why not? Because hemorrhagic stroke: you are bleeding; you're going to give aspirin, which will make you bleed if you already have hemorrhagic stroke. That's called stupid; don't do it. Only ischemic stroke prophylactically (which means before the stroke). If you know that this patient—like, he's an old guy, morbidly obese, had myocardial infarction before, had atrial fibrillation, everything—like all of the risk factors of ischemic strokes are there, give aspirin before he gets a stroke. Prevention is better than cure. However, aspirin for strokes is weakly thrombolytic. You can give aspirin after the stroke, but it's not the mainstream of treatment; you need like more aggressive stuff if you suspect a stroke, and do a non-contrast CT scan of the head. Why? To differentiate between ischemic stroke (which you may give aspirin) and hemorrhagic stroke (never give aspirin, and never give TPA because the patient is waiting, you stupid idiot).
Next, aspirin is prophylactic for antiphospholipid antibody syndrome (APS). When you have APS, we use low-dose aspirin and low molecular weight heparin (LMWH)—why?—to prevent thrombosis and subsequent miscarriages. Multi-infarct, also known as vascular dementia, which has memory loss in a stepwise fashion, which is different from Alzheimer's, because Alzheimer's is gradual, like this gradual loss of memory. Creutzfeldt-Jakob disease is rapidly progressive; it's like this rapidly. Multi-infarct, AKA vascular dementia, is stepwise; it's like this: tuk-tuk-tuk, ton, ton, ton, ton, ton, ton. Grandma doesn't remember my name; next, grandma doesn't remember her name; she's not oriented to person; next, grandma is not oriented to place; next, grandma is not oriented to time; next, grandma forgot how to use the key to open the door; next, grandma forgot how to walk. Substitute like that; it's stepwise fashion. We call this multi-infarct or vascular dementia. Aspirin is good for this, why? Because it's vascular; there are infarctions. Same thing: infarction in your brain is the same thing as infarction in your heart, pathologically speaking.
And look at this guy, Rudolph Virchow, of Virchow's triad—touted for his German—respect the language: blood stasis, endothelial damage, hypercoagulability. And he was the first guy to say leukemia, and that's where we get the term. I mean, look at this guy; look at this old-school pair of glasses, old-school suit, and also called beard with no wax, #allnatural. Thank God Virchow was not a millennial, because if he were a millennial, man, that's hypercoagulability; it's just too much for me, just too much. I don't like a triad; I'm super sensitive to number three, by the way. I can't imagine my life without dry shampoo. What can I do without dry shampoo? Maybe shower. I am a millennial, by the way. It happens to the best of us, by the way.
If you have trouble memorizing medicine and you are a visual learner, try this website called Picmonic—picture in a mnemonic; it's absolutely brilliant, and I cannot describe it in words. And, for example, the warfarin, you will see, in Picmonic, the warfarin; vitamin K is the Viking king, and as you know, warfarin inhibits the vitamin K-dependent factor, so this fairy will just shoot her bazooka at the vitamin K and destroy him. All of this you will see on Picmonic. The link is in the description; it's absolutely brilliant. They are not a sponsor of the video; I just like these guys, and I thought I would recommend those guys for you. The link is in the description, and you should do this; they are good for all of medicine, especially pharmacology, microbiology, and genetic diseases.
Let's continue: clinical uses of aspirin, aka indications of aspirin: peripheral arterial disease (PAD) or peripheral vascular disease. We have narrowing in the arteries in the periphery, hence peripheral arterial disease. This is not to be confused with central, because central is the coronary artery in your heart and the cerebral artery in your brain—coronary artery disease and cerebral vascular disease, respectively. But this is a peripheral artery in your extremity, for example. So when you have PAD, you get these symptoms: intermittent claudication pain, and it's intermittent; it's very bad. Gangrene is a possible complication of PAD. What do you do when you have a patient with PAD? Aspirin and cilostazol, and you can add verapamil; it may help.
Next, aspirin: antipyretic. Pyrex, Pyrex means like thermal; it means heat; that's why a certain type of glass that goes into the oven without explosion, we—they call it Pyrex; it's a company; they call it Pyrex, because pyretic; they got from there; it's old Greek and Latin and stuff like that. Okay, rheumatic fever? Why? Because aspirin is antipyretic. Rheumatoid arthritis? Why? Because aspirin is analgesic, anti-inflammatory. As for thighs, because aspirin's analgesic. How about an anti-inflammatory? There is no inflammation. As for thighs, maybe mild, but it's not the main thing; it's a mechanical arthritis.
A retro molar or ET; and I've talked about this in my video about essential thrombocytosis, one of the myeloproliferative disorders, and made a beautiful video about that; you should check it in my playlist called Hematology. Next, again, uses of aspirin: don't forget, antiplatelet, analgesic, antipyretic, and anti-inflammatory. Headache? Yeah, baby; it's analgesic. Headache is pain in your head. Jarisch-Herxheimer reaction: you know, syphilis is caused by Treponema pallidum. When you treat syphilis—how do you treat syphilis?—the great penicillin. Penicillin kills patients of syphilis most of the time; however, some patients have a reaction to penicillin called the Jarisch-Herxheimer reaction. This penicillin will destroy Treponema pallidum, and those ugly nasty bacteria; then, when it destroys them, the antigens are released in your blood, causing this reaction itself, limited; nothing to worry about; it's going to be okay. But if you have a patient with that reaction, you can give aspirin.
This great aspirin is protective against gallstone formation. You know, the fat, thirty-year-old, forty-year-old, fifty-four-freaking-kids female with fair complexions; they are your risk factors for gallstone disease; it's a mnemonic, come on. Then aspirin is protective against colon cancer. It can be used in lone A-fib, which means the patient has A-fib alone, with no diabetes, no hypertension, no other risk of thrombosis; give aspirin alone. But shouldn't I give warfarin? Perform ablation and shock? Shut up; go shock yourself; it's lone A-fib; give aspirin alone and leave the patient alone; don't be such an interventionist.
Next, aspirin can be used in Kawasaki disease in kids. But like five minutes ago, he told us that aspirin is not used in kids. But I've also told you that there is one exception, and here's the exception: Kawasaki disease. But aspirin produces dangerous—didn't hear about Reye's syndrome and this liver damage? Yes, I did. But did you hear about coronary thrombosis in a kid? Shut up; you should think like a mature person and balance the risk and the reward. Does the benefit outweigh the risk in cases of Kawasaki disease? The answer is yes. Perfection equals paralysis. If you left it to the engineers, no car would leave the assembly line ever, said Dan Pink. Yeah, if you left it to professors, no patient would leave the hospital. If you left it to web developers, no website will ever be ready. But the website must be robust, and the landing page must be like this, and the link should be like this; like shut up. Heavy hand of Craigslist. Craigslist was designed by luck; Kelly, I don't know, like a kid; very amateur design; very basic stuff, and it's the tenth most visited website in America, so shut up and get to work.
Next, aspirin can be used in Mondor's disease: superficial thrombophlebitis—inflammation of the vessels over veins with thrombosis. Sorry, here's the mistake; it's superficial thrombophlebitis of the breast and anterior chest wall, and you can use aspirin. Next, you can use aspirin with niacin (aka vitamin B3), why? Because niacin can cause flushing, and aspirin will reduce the flushing of niacin. I really don't know why. And next we have gout. Why use aspirin in gout? One, because there is pain in gout; aspirin is analgesic. Next, gout can have some—and it's an inflammatory arthritis, so aspirin is anti-inflammatory. But it's not—not the mainstay treatment of gout, but it can help. Aspirin can be used in temporal arteritis, also a nice giant cell arteritis, but don't forget to give the steroids, of course. The steroids is what saves the patient's eyesight, not the aspirin. Yes, but it can help; yeah, it's analgesic; can help with the pain, but again, it's not to replace steroids. Okay. Oh, by the way, I have a great video about temporal arteritis; just Google Medicosis Temporal Arteritis; you will find it.
Kawasaki disease: risk versus benefit analysis. Are you sure you want to give aspirin to the kid? Okay, what is the risk? Reye's syndrome. What is the benefit? Protection against coronary artery thrombosis. Does the benefit outweigh the risk? And the answer, most of the time, is yes, so give aspirin and give intravenous immunoglobulin. By the way, I have the perfect, ultimate notebook about lymphoma on my Patreon; it's 100+ pages and it's 100+ megabytes and has 20 cases about lymphoma. And if you were to get it now, you get 25 bleeding cases. Quiz time: When not to give aspirin to a child with Kawasaki disease? And please don't say allergy; this is not the answer that I'm looking for. So this is the exception of the exception. Number one: don't give aspirin to kids, except when they have Kawasaki disease. But most of the time, except when there is—let me know the answer in the comments. You can get the answer now at patreon.com/medicosis, for just $1. Plus, you get many other notes for just the same dollar, so it's a deal. Thank you so much, guys, for watching. We'll talk about the side effects of acetyl salicylic acid in the next video. In the meantime, please subscribe and hit the bell to get notified. Follow me on Facebook; I have more than 95 cases on Facebook. And to get my Dropbox links about notes and cases—all of my notes, all of my illustrations that I'm doing for these videos are available in PDF forms that you can download: patreon.com/medicosis. Thank you so much for watching. This is me, Medicosis Perfection, where medicine makes perfect sense. Medicine and sense—towards that—don't come together like customer service. Anyways, be safe, stay happy, and study hard.