(CC) 1st vs 2nd Generation Antihistamines (CH 3 RESPIRATORY NAPLEX / NCLEX PHARMACOLOGY REVIEW)
March 5, 2020
Okay, this is from chapter three respiratory, its first- versus second-generation antihistamines, and it seems like a simple concept, but you can actually get a lot out it if you create the questions right and I’ll show you what I mean. The first thing we do is we say first generation versus second generation, what’s the difference. Usually the second generation has some kind of improvement in third generation, fourth generation and so on. The first generation is diphenhydramine or Benadryl, and that caused drowsiness. That was a bad thing, and the second generation improved that by making it so it’s not drowsy. You have loratadine which is Claritin, cetirizine which is Zyrtec, fexofenadine which is Allegra, and I can give more examples of first versus second-generation but these are the most common. To learn this or to learn any fact you really want to do practice questions, and people get hung up on hundreds of questions but you don’t need to do that many questions. What you really want to do is have questions that help you learn from each of the answers, and that’s why people look at the rationales and are so excited about the rationale, so let me show you what I mean. We’re going to go through five practice questions and the issue with listening to practice questions on audio is that your working memory can’t process all of the four answers if they’re not in some order, or they’re not related. What I find is that you know you’ll hear something on an audio book or something like that about oh, here’s a thousand questions that you can learn from, but if you’re working memory can’t put the whole thing in your brain at once, then that’s not going to be really helpful. What we want to do is we want to create practice questions that are related and we just change a little bit and by changing just a little bit and having the same answers each time, it actually works out a little bit better, a little bit easier to remember. Here’s a practice question. ‘A truck driver asked which antihistamine he can take to stop his runny nose and sneezing today, you tell him to take a?’ I’m going to actually not even mess with drug names yet, and just put the drug classes. Very good NCLEX or NAPLEX or USMLE practice question would have every single one of the incorrect answers teach you something or be part of an important part of the question. The first answer would be a first generation antihistamine. I put this in green if you’re watching it if you’re just listening, I’ll try to go over it again, and you’ll see the first generation antihistamine makes you drowsy, so if the person’s a truck driver and he asked for something for today. No, we wouldn’t want to use a first generation antihistamine. Second generation antihistamine, it’s non-sedating. Yes, that’s what we want to use. It meets all of our criteria the truck driver needs to be alert, so it can’t be sedating. It’s an antihistamine, we need to stop his runny nose and sneezing and that’s the symptoms that you might have, and then it’s for today. Decongestant, this is something patients often confuse as antihistamine versus decongestant. Know a decongestant is for nasal congestion. He has runny nose and sneezing, this wouldn’t help. A nasal steroid, this would help, but it’s neither an antihistamine nor will it help runny nose and sneezing today. It’s used for prophylaxis. It’s not an acute medication. That’s what make the second one right and what makes pharmacology so hard is that there are so many different first-generation, second-generation antihistamines, decongestants, and nasal steroids. What we can do is we can create a second practice question and we’re only going to change a little bit each time. ‘A truck driver asks which antihistamine he can take for his runny nose and sneezing during the day’ and you tell him to take, and Instead of the drug classes all I’ve done is replaced it with some of the most common medications, and that’s really what you’re going to see As much as you think the the board is trying to trick you, they’re really trying to use some of the more common medications that you would be more likely see. Diphenhydramine, which is Benadryl would make a person drowsy, so no, that’s not right. We’ve just switched the second-generation antihistamine loratadine for something non-sedating, so yeah, that’s the right answer still. We remember that the stem ‘-atadine’ is a second-generation antihistamine. Pseudoephedrine, again, this is the decongestant, so it doesn’t help with the symptoms so no that’s not correct. Fluticasone, the -‘sone’ isn’t a stem but you’ll often see it with steroids. This is again a prophylactic, not an acute medication, so all we’ve done is Changed from drug classes to the drugs themselves. We haven’t even changed the question. What we want to do, because our working memory really couldn’t take this much information in, is continue to repeat parts of it and make a small change in the question. The answers are going to be the same, it’s going to be a diphenhydramine, first generation antihistamine, loratadine, a second generation antihistamine, C) pseudoephedrine, a decongestant and D) fluticasone, glucocorticoid or a nasal steroid. Let’s see how this works. Practice question three: ‘A truck driver asks which antihistamine he can take for sleep at night you tell them to take?’ and now although all the answers are the same, the correct answer changes. A) diphenhydramine makes you drowsy so that’s good. This is the active ingredient in Tylenol PM, the PM stands for nighttime or post meridian, but it really stands for at night. Diphenhydramine would be now the correct answer. Loratadine would be incorrect because it is non-sedating. It doesn’t help with sleep. Pseudoephedrine, this not only doesn’t help with the symptoms, but it would actually keep them up at night, so that would be the opposite. Fluticasone is a prophylactic steroid and really wouldn’t help someone who’s trying to get to sleep at night. What we’re really trying to do is continue with the same question or continue with the same answers so that we can learn. The first thing we do is we learn why something is right, and then we want to learn how to make the other three right so that we really learn well, how it’s wrong. ‘The truck driver asks which antihistamine you can take for sleep at night and youtell them to take diphenhydramine because it makes them drowsy. Okay, how can we make pseudoephedrine right? We just say ‘A truck driver asks which medicine he can take for nasal congestion?’ and you tell them to take pseudoephedrine. We have to be careful here because we haven’t considered some other things. Again, these are just practice questions I’ve made up, but with diphenhydramine there might be a little bit of hangover effect and that might be a consideration if we’re getting into the details. pseudoephedrine This might be an issue because a truck driver may not be allowed to take something like pseudoephedrine which is a stimulant and this is what people use to make methamphetamine. We’re working within the question and we’re just looking for a nasal something for Nasal congestion, but know that there might be some idiosyncrasies that go outside of the question. What we want to do is continue with the same question answers, diphenhydramine, loratadine, pseudoephedrine, fluticasone. What would we have to do to the question to make fluticasone right? Practice question five ‘A truck driver asks which medicine you can take for runny nose and sneezing two weeks before allergy season starts?’ you tell them to take fluticasone. Fluticasone is an intranasal steroid. You can use it for prophylaxis, and yes, this makes it right. Again trying to get away from I have to do x number of questions and say let me spend a little bit more time with each question so that I can really understand why the first answer was right and then by making the other ones right by changing the questions, it really helps put this into your memory.