 Hi and welcome to nursing school explained. Today I'd like to go over respiratory medications. This seems to be a topic that a lot of times is kind of confusing to students. But when we really think about the mechanism of action of a medication really represents its physiology and the physiological response that it will enhance or inhibit in the body. So I have written down here some basic terms that hopefully will help you be able to dissect the mechanism of action of these medications and then understand how they work and so also how they're indicated and why they would be used in the treatment of certain respiratory disorders. So first of all I just wanted to review inflammatory mediators. You might remember from your physiology class all the different cells that help us in providing inflammation when we are battling infection disease allergies any of those things in the body. And some of those mediators I've written down here so those are neutrophils you know those are the number one defense and we also have mast cells, macrophages, leukotrients, T cells, histamines. Now remember these are only a few of the inflammatory meters there's there's a lot of other ones but these are the most important that we will apply here to the respiratory medications. And then other principles here and this not only pertains to respiratory medications this pertains to cardiac medications as well. And so whenever you see the word adrenergic think adrenaline think sympathetic nervous system and phytophyte response so adrenaline adrenergic response sympathetic nervous system where cholinergic pertains to the parasympathetic nervous system okay so whenever you see these terms adrenergic or cholinergic you know that they are working either on the sympathetic or parasympathetic nervous system. And then in addition medications can be agonists or antagonists or they can be anti against something. So an agonist helps to promote the natural response by occupying their receptor site. Remember that most of the physiological mechanisms that take place in our bodies is kind of like a key in the lock mechanism so only certain keys will fit to certain receptor sites and be able to initiate a response. So an agonist is basically a chemical or a pharmaceutical or response that we're trying to elicit. So when it's agonist it helps to promote or agonize that response where an antagonist as you can imagine does exactly the opposite so it blocks the receptor sites. So when we don't want something to happen when we want to inhibit certain things from happening that key and lock to match then we want to give an antagonist because that pharmaceutical that medication then will block that receptor site as basically like a fake key so the natural response cannot occur or is inhibited. And then there's also medications that start with anti and they are basically just means that it's against something. So kind of similar to antagonist but almost like just a different terminology that is used. Now another graph that I've drawn out here over here is basically beta 1 and beta 2 and then alpha because there's beta 2 adrenergic receptor blockers for example alpha adrenergic receptor blockers or beta cholinergic there's all kinds of different combinations but remember beta 1 we have one heart so beta 1 always pertains to the heart. Now we have two lungs so beta 2 always pertains to the lungs as I've drawn out here the heart is beta 1 beta 1 one heart beta 2 we have two lungs so that pertains to beta 2 and then this here is an alpha turn on its side alpha means blood vessels so this would be the structures of the blood vessels flowing throughout the body in this little graph here. So beta 1 heart beta 2 lungs alpha pertains to the blood vessels and that for the blood vessels it mostly means are they dilating or constricting are they having a sympathetic or parasympathetic nervous system response and then the mechanism of action can be easily identified. So back to our respiratory medications so there are a variety of classifications there this mostly applies to asthma but they can also be used in conditions such as chronic obstructive pulmonary disease, emphysema, maybe cystic fibrosis or for acute respiratory disorder such as bronchitis where there might be some acute inflammation not chronic like in asthma where the patient might benefit from a short course of one of these medications. So let's look at that. So number one I've written out SABA and SABA stands for short acting beta 2 adrenergic agonist okay so very short acting so beta 2 lungs adrenergic sympathetic nervous system okay so basically this binds to the beta 2 adrenergic receptors therefore it relaxes the airway smooth muscle and causes bronchodilation right when we have a sympathetic nervous system response when we need to get ready to fight to a flight when we need to get ready to run away we need to be able to dilate our bronchioles by allowing more oxygen exchange because with our muscles we'll need that oxygen for the flight or fight response so therefore short acting beta 2 pertaining to the lungs adrenergic sympathetic nervous system agonist it's going to help to promote that natural response by relaxing the smooth the air with muscle airways and causing bronchodilation and really the only SABA there is is albuterol I'm sure you've heard about it it's the most commonly used inhaled medication now I've written down here OP and D which is onset peak and duration because later we'll compare it to some of these other medications so albuterol the onset is five to 15 minutes its peak occurs at two to three hours and it lasts for about four to six hours so this is something that we need to keep in mind whenever we're doing patient teaching regarding these medications how soon can they expect this to work now classification number two is ICS which are inhaled corticosteroids and you might know that steroids always battle inflammation so now looking back at these inflammatory mediators so which ones in particular do those inhaled corticosteroids inhibit so for inhaled corticosteroids they decrease airway inflammation but they work on multiple inflammatory mediators so they don't just pick out neutrophils or mass cells or leukotrients they work on multiple mediators which is why they are the most commonly used inhaled anti-inflammatory medication because they work on a variety of different cells therefore inhibiting that inflammatory response that causes bronchoconstriction and then causes problems for the patient and these inhaled steroids just like any steroids usually end in own so an example would be bechloromethazone flutectazone just like your corticosteroids your PO would be your prednisone for example they all end in own and if you can remember these endings of these medications and connect them to the classification it will be much easier for you to remember and kind of classify them and then only memorize the drug category rather than memorizing all the individual medications because there's just way too many out there so number three medications would be alaba so you can see it's very similar the only difference is it's a long acting beta-2 adrenergic agonist so it's exactly the same thing as up here except that it's longer acting so the mechanism of action is the same as a saba but it's longer acting the example here would be salmeterol again ending in ol which is pretty typical for these adrenergic agonists now we already know that beta-2 applies to lungs adrenergic phytoflightadrenaline pertains to the sympathetic nervous system so it does exactly the same as the albuterol where it binds to those beta-2 adrenergic receptor sites relaxing the bronchial smooth muscle and allowing for bronchodilation so the patient can breathe easier now looking at onset peak and duration over here so onset is one hour you can see it's short it's longer than up here the peak is one to five hours and the duration up to 24 hours so it's long acting right long acting 24 hours compared to short acting four to six hours for duration up here now number four would be anti cholinergic medications and we already talked about cholinergic meaning that it pertains to the parasympathetic nervous system i move back over here so cholinergic pertains to the parasympathetic nervous system and anti means against now why would we want to block or counteract the parasympathetic nervous system now think about it if we again are in a phytoflight response we want that sympathetic nervous system to kick in cholinergic or parasympathetic nervous system is in charge of rest and digest right when we need to flee from a danger there is no need for rest and digest all the blood flow needs to go to the important organs the heart and the lungs and the muscles so that we can run away from the danger so anti cholinergic medications anti meaning it inhibits the cholinergic receptor sites in the airways so now we are inhibiting the parasympathetic nervous system from kind of slowing everything down and constricting the bronchial so we can rest and digest and when we inhibit the cholinergic response it also brings us bronchial dilation so bronchial dilation here is the end effect in sabas labas as well as anticholinergics but they work in different ways so anticholinergics working on the parasympathetic nervous system basically just blocking those receptor sites so they don't have a chance to cause bronchial constriction because that's what they would do for rest and digest response and an example for an anticholinergic respiratory inhaled medication would be atrovent or aprotropium you probably have heard that before as well now in comparison the onset peak and duration for anticholinergic so onset is one to three hours the peak is one to two and duration four to six so you can see it's very similar to the albuterol in terms of the duration so it'll last about the same time now there are certain medications that can be given to patients that are used in combination and one of the the ones used very frequently in the emergency department is called a duo neb so duo duo two medications by nebulizer and that's always a combination of aburo a saba and the atrovent the anticholinergic so they both combine work together to agonize the sympathetic nervous system and antagonize the colinergic system so that bronchodilation can occur on both pathways remember that every organ has innovation from sympathetic and parasympathetic nervous system receptors so that they can work either to speed things up or so slow things down now number five here leukotriene antagonists so you can see here leukotrienes are one of those inflammatory markers we reviewed earlier and they are basically a very specific they respond to very specific inflammation response and so these leukotriene antagonists they do just that they block the receptor sites for the leukotrienes so which which usually would cause inflammation and therefore they antagonize that so they decrease the effect of the leukotrienes and cause decreased inflammation and that would be specifically a desired response in patients with asthma where there's a lot of underlying inflammation and other respiratory conditions that have inflammation at their at their core and an example of a leukotriene antagonist would be singular or Montelucast is the other the generic version of it now then further we have mast cell stabilizers again mast cells are different inflammatory mediators and when we stabilize the mast cells then again we decrease inflammation so they're again very specific to those specific inflammatory markers and an example would be chromolensodium and then in addition as if this wasn't enough already we have certain combination medications and these combination medications usually are consist of an ICS an in-health cortical steroid and a laba a long-acting beta adrenergic agonist the most commonly used one is advere that's that purple discuss that you might have seen in the clinical setting and it consists of some meter all which is our lava and for ticker zone you know our owns are our in-health cortical steroids and then in-health cortical steroids also come in low medium or high doses so depending on the severity of the patient's asthma they'll be on the strength basically the more severe the asthma the higher strength of the higher overdose the patient will need let's see so i hope this has clarified the medications for you now when we think about asthma think about that the patient will always need a sabre which is also called a rescue medication rescue so this is something that the patient should have with them at all times and depending on the severity so maybe all they have is allergies in the springtime and when everything is in bloom when they go outside they need that our bureau with them otherwise they get short of breath because this inflammation starts but if this is somebody who is let's say allergic to dust mites or dogs and now they have a dog or some there have some other allergen that's basically year-round that requires the inflammation in their lungs to be controlled on a more regular basis than they'll be on an in-health cortical steroid in addition to a rescue medication now if this is somebody who let's say has COPD and Pizema one of those other chronic lung disorders where now we need to have longer acting bronchodilation then they'll usually be on a laba and an ICS so they'll be on something like ADVIR now this is definitely nothing that nurses need to worry about in terms of prescribing because it'll always be up to the provider to find the most fitting medication for the patients but keep in mind it is very important to understand the mechanisms and how they work and if you know the mechanism of action you will always know how they work what they what response they initiate in the physiology and then you can apply it so I would recommend that you memorize this andrenergic cholinergic agonist antagonist as well as the receptors beta one beta two and alpha that way you can kind of combine these terms and know what's going on to kind of dissect the meaning of these respiratory medications thank you for watching I appreciate your time please share this video if you found it helpful and subscribe to my channel at nursing school explain you can also follow me on instagram to make sure you get the most recent updates as well as my latest videos thanks very much see you next time