if i gave you a whole list and said which of these statements is true about the mechanism of action of epinephrine and atropine would you get it right let's find out but in this video you're good to know it cold every medication or drug has three names the chemical name which we're never really going to see at for the lab but i put it here for you the chemical name so in this example we're using tylenol the generic name we're going to see a lot with our patients on their med list talking about medications and also on the patient's pill bottles themselves so generic name acetaminophen the brain or train name that's tylenol so the patient may be familiar with generic or the brand when you speak with them this right here is what a drug card looks like so we're filling our drug cars in paramedical this is what they look like we start generic and brand name the class the class means essentially like for example the drug was a anti-hypertensive medication or antipyretic medication or sympathomimetic we're going to talk about all these things in a little bit so what does a drug do basically is how it determines its class right mechanism of action is what the drug does when it enters the body how does the drug have its effect the mechanism of action is so important for the moa why it's so important if i know what a drug does and i understand the mechanism of action and how it translates to what goes on in the body i can fill out this whole drug card basically all the indication of conjugate cases for example if i know a drug is going to increase someone's heart rate right if the indication means when i give it so if i know a drug increases the heart rate of a patient if their heart rate's too low i might want to give it but what would i not give it if it's already too high right what might be ever's effects be i'm gonna raise your heart rate up you might get restless you might get anxiety you might get palpitations right dose that's determinant on the drug and then what route so what route am i gonna give this drug is it going to be iv is it io is it po is oral what is it is it intramuscular what is it and every drug has some special considerations that you want to think about when giving the drug so we have here the sympathetic and the parasympathetic nervous system one is fight or flight one is rest and digest so the thing about a sympathetic and the parasympathetic nervous system is they're always in balance with each other depending on what's going on right remember this pupils heart rate blood pressure respiratory rate and digestion those are the key factors of what they do so in sympathetic if i'm in a fight or i'm fleeing because a giant lion is chasing me right what is my body gonna do well my pupils are gonna dilate so i can see better also my heart rate is going to increase my blood pressure is going to increase my respiratory rate is going to increase so i'm able to move and perform better right and also we're not going to worry about digesting that food i had two hours ago there's a lion chasing me so we're gonna reduce digestion now with parasympathetic it's rest and digest so now you're relaxed you're back you're hanging out you're getting ready to go to bed right think about right that's the way i think about it so people start to get constricted heart rate and blood pressure go down respiratory rate goes down and and digestion is going to be increased in the rest and digest face okay so that's what we're looking at for sympathetic first parasympathetic let's get a little more advanced now now we just learned about the sympathetic and parasympathetic i have some key terms for you gotta know this sympathomimetics what that is it's a drug that mimics the actions of the body's sympathetic nervous system thus turning it on right so these drugs are also called adrenergics because they're related to that receptor in the body okay so sympathemetics could also call adrenergics you might hear that i want to tell you about that now notice this sympatholytics do the opposite effects so we get a parasympathetic effect from a sympatholytic we're shutting off the sympathetic side so sympathoid medics turn on the sympathetic nervous system sympatholytics shut it off aginergix that goes with the the sympathomet now over here parasympathetics that's going to turn on the parasympathetic system a parasympatholytic for example like atropine right epinephrine would be a sympathomimetic atropine would be a parasympatholytic because it's going to shut off this side and turn on this side right a cholinergic drug that turns on that receptor that has to go with parasympathomimetic it's a mouthful i know but you gotta know these words they're gonna come up in class and on exam day now real quick the top part of this that we we talked about the bottom part the top part is agonist versus antagonist so an agonist is any drug that turns on a receptor and i'm going to teach you right here in a second about the different receptors that we're going to learn about now the an agonist turn the receptor on so let's say let's just say a receptor when we turn it on caused vasoconstriction that's an agonist now what if a drug enters the body and it's a blocker okay it's an antagonist then that means it would go into that receptor and it would block the action right so let's go a little deeper on this topic these are the main three receptors you need to know in ems so let's talk about first when they're activated what happens so let's say the alpha 1 receptor is turned on right is there's an action being taken place we get vasoconstriction okay of the blood vessels vasoconstriction beta 1 we have one heart so beta 1 has to do with the heart it's going to increase the heart rate of the patient and this is a big word contractility there it is the contractility how well the heart can contract so it makes a stronger beating heart that's going to increase the heart rate beta 2 receptors we have two lungs so we're going to dilate the patient's lung now think about this for a minute if your patient's having an asthma attack would it make sense to give a drug that's an agonist to the beta2 receptor we do that that's albuterol right that's epinephrine too right someone anaphylaxis they're wheezing we give epi and albuterol that acts in the beta 2 because we want bronchodilation we want the bronchioles in the lungs to open up now you're getting it what if someone's heart rate's too low i might want to give an agonist of a beta 1 drug like epinephrine to raise their heart rate and increase the contractility of their heart because it's so slow and low right what if someone's got low blood pressure would i want to give a vasoconstricting agent to raise their blood pressure in certain circumstances yes epinephrine does that too right now we see here epinephrine which is the main really it really is the main drug of ems epinephrine it's emergency medication it's an agonist on alpha 1 beta 1 and beta 2. it's a sympathometic and it does it acts on all these receptors now i'm going to throw a little curveball at you what if the your patient takes a medication it ends in o l o l that's a beta blocker wait a second i just learned about that yeah well beta blockers are in the could it already be in your patient meaning the pigeon is a beta blocker it's the opposite effect so would it make sense if you were a doctor to prescribe somebody that actually has asthma in their history would it make sense to prescribe them a beta blocker when we can do something different that wouldn't make sense basically we know right here right because if we block the beta2 receptor we get the opposite effect which would be bronchoconstriction whoa you see where i'm going so that would be a special consideration see how we're learning right so again if we block the beta receptors i'm going to give you one more pearl here i got to give it to you most beta blocker drugs that are a antagonist that block the beta receptors the majority of them try to select which beta receptor they want to block right so some beta blockers for example why do we get beta blockers in the first place well the patient would be prescribed a beta blocker because they want to lower their high blood pressure right so beta 1 can lower the heart rates to lower the conductivity of the heart we're gonna lower the patient's blood pressure right so the thing is if we give any beta drug even if it selects the beta one there's still twins there's always a little crossover effect into the other one so that's something to keep in mind now we learned how epinephrine is a sympathetic it's going to go in the body and mimic our own sympathetic nervous system it's going to increase our heart rate right now what about atropine how does atropine increase the patient's heart rate but it's not a sympathometic it's something different so atropine is a parasympatholytic so what this means atropine goes in it's going to again sympathetic and parasympathetic are always in balance so it's going to lower the parasympathetic's ability to work so by default sympathetic goes up right so we get a effect that looks like the sympathetic is turned on but really parasympathetic is just down so we get an increased heart rate meaning what actually happens our vagus nerve think about it being plugged in to the heart right so when patients have a really hard uh high heart rate in the ambulance we can have them bear down like they're passing a bowel movement to actually lower their heart rate that turns on the vagus nerve and gives them a parasympathetic response pretty cool right now what atropine does atropine basically makes a roadblock and a block in that vagus nerve thus parasympathetic can't act in the heart so the heart goes well this nerve is down right now i'm gonna go increase right so that's how atropine is able to increase the heart rate it lowers your parasympathetic response so now you tell me what is true of the mechanism of action of epi and atropine i'm gonna give you five seconds five four three two one remember here it is epinephrine is an agonist that is a sympathomimetic it's going to act and turn on the alpha 1 beta 1 beta2 receptor thus we get vasoconstriction increased heart rate bronchodilation right atropine atropine is a parasympatholytic it's going to be the roadblock at our vagus nerve so the parasympathetic response goes down thus leads to the heart rate increasing and this is why atropine is given for bradycardias with symptoms because it is able to raise that heart rate and there it is and the first link in description down below is what i give to all my students getting ready for school in school right now or getting ready for their national registry exam to get lifetime access videos quizzes and access to me to answer your questions hit that link down below and you're gonna see a video right here go watch it right now you're gonna love it