Cyclooxygenase (COX) and Prostaglandins – NSAIDs (Nursing)

by Prof. Lawes

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    00:01 So, NSAIDs and cyclooxygenase, let's break this down a little bit.

    00:04 Because nonsteroidal anti-inflammatory drugs block the Cox enzymes.

    00:10 Okay, so, that's how they work.

    00:12 When you take the nonsteroidal anti-inflammatory, that's why relieves pain, and inflammation.

    00:18 And remember that third one, it also deals with fever.

    00:21 Because you need Cox to create prostaglandins and thromboxanes throughout the body.

    00:27 So, when we have Cox inhibitors, we're gonna have less prostaglandins and less thromboxanes.

    00:33 Well, less prostaglandins has a widespread effect on the body.

    00:37 We'll talk more about that.

    00:39 Less thromboxane means I'm gonna be a little more likely to bleed, or less likely to develop a clot.

    00:45 So, NSAIDs equals less Cox, so that means there will be less prostaglandins and less thromboxane.

    00:51 That's the takeaway point, you got it.

    00:54 Because Cox is essential so I have prostaglandins and thromboxanes.

    00:58 Remember it's involved in the process of creating it, if I'm taking NSAIDs, I'll have less of both.

    01:05 So, we gotta have them for prostaglandin and thromboxane synthesis.

    01:10 We've come at you with all different angles so you have that concept down.

    01:15 Why you need to know that is it's critically important in recognizing which patients it's not safe for them to take these medications and what the risks and problems could be? So, you've got prostaglandins in most tissues and organs.

    01:29 Because they're produced by all nucleated cells, except the lymphocytes, but we'll get back to that later.

    01:35 Prostaglandins are produced by most all of the nucleated cells except the? Right, lymphocytes.

    01:41 Now, makes it from the essential fatty acids: gamma-linolenic acid, there's our friend again, arachidonic acid, which reminds me of spiders, and the last one, look at that last one, starts with an e.

    01:56 Okay, so why are we talking about all of these things? Well, those are just names of the essential fatty acids that prostaglandins are produced from.

    02:07 That's what the value of that is. Can you memorize all those? Probably not but we want you to have the concept that prostaglandins are produced by all nucleated cells except those lymphocytes and it comes from essential fatty acids.

    02:21 So, prostaglandins are a family of chemicals that have really important roles in your body.

    02:27 They support the blood-clotting function of platelets. So, in order for my platelets to be healthy, I need to have healthy levels of prostaglandins.

    02:37 Remember what happens to the prostaglandins when you're taking Cox inhibitors.

    02:41 So, I also need these prostaglandins to support and protect the lining of the stomach from the damaging effects of acid.

    02:50 See, I need prostaglandins at an appropriate and healthy level of them because in order to keep those really sensitive skins cell inside the lining, the epithelial lining of my stomach protected from the gastric acid, I have to have healthy mucus and bicarbonate coated all inside my stomach.

    03:10 If I don't have an adequate prostaglandin level, I'm gonna have less of that protective coating that can neutralize the gastric acid and protect my epithelial cells.

    03:21 So, I need prostaglandins to support blood-clotting function of platelets; I need it to protect the lining of my stomach from damage from the gastric acid.

    03:31 And prostaglandins promote inflammation.

    03:35 Now, inflammation doesn't always feel great, but we really need it for healing.

    03:40 So, you can have pain with it, but it's important part of the healing process.

    03:45 So, prostaglandins, what: clotting functions, protect the stomach lining, promote inflammation that we need for healing, that can also result in pain and fever.

    03:58 Well, that makes sense if I take Cox inhibitors and I have less prostaglandins, I'm gonna have less of all that activity.

    04:06 That's why we can use it for pain, inflammation and fever.

    04:11 But bump up to point number two that means my stomach might not do well with NSAIDs.

    04:16 Maybe yours doesn't either. What about the blood-clotting function? I know if I am taking an NSAID, then I'm not gonna clot as well as I would if I wasn't taking an NSAID.

    04:28 Often, results are dose-dependent.

    04:30 The more I take, the more often I take it, the more significant the impact will be on my body.

    04:36 So, let's look at how Cox-1 and Cox-2 kinda have little bit different roles.

    04:40 We introduced you to that in the beginning, where we showed you the picture, but let's look at it now.

    04:46 Both Cox-1 and Cox-2 produce prostaglandins that promote pain, inflammation, and fever.

    04:52 So, if we give a Cox inhibitor, we're gonna diminish that.

    04:55 Aspirin, ibuprofen, leproxin: they all block the action of both.

    05:02 Now, you see in our graphic there, we've showed you with the color going across both sides, we've got it meet in the middle. That helps you remember Cox-1 and Cox-2 both do this.

    05:12 So, what's different about Cox-1 and Cox-2? Well, Cox-1 produces prostaglandins that activate platelets and protect the stomach and intestinal lining.

    05:24 So, definitely gonna have some issues with that if they activate platelets, that means I'm gonna be more likely to bleed, less likely to clot.

    05:32 And my stomach is gonna be kind of at risk for having some irritation.

    05:37 Okay, didn't you wonder why these are called prostaglandins? Kind of a weird name. Well, there's a story behind that.

    05:46 So close, and yet, so far is what I like to label this one.

    05:50 You see, in 1935, the first prostaglandins were isolated by two really smart men.

    05:57 You got their names up there. But the sample was from seminal fluid.

    06:02 So, they thought prostaglandins had to be from the prostate.

    06:06 That's why they're called by prostaglandins.

    06:09 Now we know that prostaglandins are produced by all nucleated cells except the lymphocytes.

    06:15 But, still an amazing discovery for 1935. They were just, missed it by that much.

    06:23 So, prostaglandins need Cox.

    06:28 Now, we've talked about that, before you look at that slide, I know.

    06:30 Even if you've already read it.

    06:32 Pause for just a minute and see if you can put into your own words. Why do prostaglandins need Cox? Okay, hopefully you came up with that Cox-1 and Cox-2 are enzymes, right? Cyclooxygenase. The A-S-E tells us that they're enzymes.

    06:54 So, both of the enzymes, Cox-1 and Cox-2 are critical to producing prostaglandins, and we need prostaglandins in the appropriate level in our bodies.

    07:05 See, our body needs these, because prostaglandins promote healing and safety.

    07:10 Sometimes it doesn't feel great because you end up with pain, and inflammation and fever.

    07:15 And man, I've got a hip that can really feel it sometimes. But it's still part of our healing process.

    07:21 So, Cox-1 produces prostaglandins that support platelets and protect the stomach.

    07:27 Okay, now, that's real specific, but we've talked about the different processes of Cox-1 and Cox-2.

    07:33 Remember the drugs that we're talking about block both.

    07:36 But I just wanted to remind you, Cox-1, those prostaglandins support platelets and protecting the stomach.

    07:44 So, if I have less of them, then I'm gonna have less protection for my stomach, and I'm gonna have less opportunity for the platelets to do what they do to clot.

    07:54 So, we've established that prostaglandins need Cox.

    07:59 But when I try to remember what I used them to treat, since NSAIDs reduce Cox-1 and Cox-2, there's less prostaglandins, so I used them to treat PIF.

    08:08 Yeah, that's how I remember it. Pain, inflammation, and fever. PIF. So, prostaglandins treat PIF. You got it.

    08:18 Now, just because that's something that works in my brain, doesn't mean that it works in yours.

    08:23 But I thought I'd share it with you, anyway.

    08:25 As you're going along, really so many of those that you can remember.

    08:30 So, use them, judiciously or wisely, but if it's anything that uses a different sound or a different grouping, sometimes that can help you really lock in the rationale.

    08:42 Now, this is just a memory mnemonic but we've shown you how and why Cox-1 and Cox-2 reduced these three things.

    08:51 So, it's not enough to know that we just use these for pain, inflammation, and fever or PIF.

    08:56 It's important that you understand why. What's the role of Cox-1? What's the role of Cox-2? And how do we end up with less when we give these NSAIDs?

    About the Lecture

    The lecture Cyclooxygenase (COX) and Prostaglandins – NSAIDs (Nursing) by Prof. Lawes is from the course Central Nervous System (CNS) Medications (Nursing).

    Author of lecture Cyclooxygenase (COX) and Prostaglandins – NSAIDs (Nursing)

     Prof. Lawes

    Prof. Lawes

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    By Andrés N. on 04. June 2021 for Cyclooxygenase (COX) and Prostaglandins – NSAIDs (Nursing)

    Excellent lecture, thank you for letting me learn NSAIDs in an easy and memorable way!