Transcript for:
Pharmacology for Nursing: Gastrointestinal Drug Groupings

this is Professor Hoffman uh topic 10 for pharmacology for nursing is going to cover gastrointestinal drug uh groupings uh first we're going to be looking at the anti-ulcer drugs in topic 10A and then in topic 10B we'll uh switch over to the laxative groups so looking at the materials for uh the antiulcer groups are going to be found in section 7.3 of your text so with anti-ulcer drugs we're looking at medications that to treat uh and give symptom relief for gastrointestinal ulcers now ulcers in the GI tract are an erosion of the lining it's going to create pain uh as the mucosal lining and the epithelial lining of the G track becomes irritated and goes through the injury mode that type of thing also increases the risk for bleeding as that tissy roads and blood uh capillary beds are exposed GI ulcers are a result of increased acidity when we look at the acid base balance in the body we usually think of the blood pH being a very narrow range of uh 7.35 to 7.45 uh for pH levels in the GI tract though we have a very wide range because the acidity of the GI tract is what helps um the process of digestion so as we look through the GI tract starting at the mouth and the esophagus uh the pH in that area is going to be slightly acidic to neutral so about 6.5 to 7.5 uh for pH when we get to the stomach however we introduce hydrochloric acid to start to break down um of foods and begin the digestive process and the pH in the stomach can drop down to 1.5 to 4.0 so extremely acidic once the contents leave the stomach uh and move into the duodenum and the small intestine um bicarb is added uh to the contents and the pH goes back up to seven in some parts of the small intestine is high is 8.5 but generally more of a neutral and on either side of a neutral level uh when we get in the small intestine but again in the stomach we're going to have this hydrochloric acid that's going to keep us in that 1.5 to 4.0 uh PH range and again that's necessary along with producing the acid however the stomach also produces um protective um secretions that coat the the lining of the stomach so the acid does not normally cause erosion or problems so we're going to develop ulcers or the potential for ulcers when we have either hyper acidity we have more acid being produced and is necessary or for some reason we break down those defense mechanisms uh that produce that protective barrier so those are the two kinds of things can go on where we're going to see the evidence of the ulcers depends on where the irritation happens in gird or gastro esophageal reflux disease uh some of that stomach acid refluxes or moves upward into the lower part of the esophagus again the esophagus is designed to handle a pH more in the 6.5 to 7 7.5 range it's not going to have the protective um coating that the stomach has because it's not designed for that low of a pH so when the acids reflects up into the esophagus we're going to start seeing irritation breakdown and destruction of those lines ings and so we can see an ulcer ulcerated areas in the esophagus again that would be uh the the definition of gird or the gastro hopal reflux disease uh the ulcers can also developed though in the stomach and in the dadum again this is going to be possibly because we have uh excessive acid production or particularly in the stomach it may be because may be due to lowering that protective mechanism so peptic ulcer disease when you hear that PUD or peptic ulcer disease diagnosis we're looking at ulcerations that are taking place in the stomach or the duum the assessments that's going to go into this diagnosis is going to be the general physical assessment what the history has been evidence of pain that type of thing also going to be looking at medications remember we talked about nids uh previously and we talked about one of the um side effects or effects of the nids as they block the Cox one and Cox 2 prostate landons is that it does decrease the production of that protective layer in the stomach so n sets can be a contributing factor to De developing um a PUD uh implementation of treatment uh we really want to make sure the individuals understand when to take the medications how to take them that they're compliant with that but we also want to look into the patients preferences there are other non-pharmacological approaches or over thee counter type approaches um things that we may see as me more home remedy approaches that can be effective as well we need to understand where the where the patient coming from what kind of treatment they would prefer to process or if they're using some of um the home remedy type things that we're aware of that because that will impact on anything we add to their regimen in terms of medications the evaluation of the use of ant acids and is going to be mainly their effectiveness there should be an improvement in symptoms should be a decrease in the pain and um if we use scoping to look at the stomach line we should see an improvement in the condition of stomach planning again remember stomach lining is um made up of cells that once they're given the opportunity will reproduce and regenerate fairly quickly we're also going to watch for negative developments if the treatment is not successful there's going to be increased pain there's going to be nausea and vomiting and we particularly want to watch out for any evidence of bleeding because as that lining erods and the capillary beds are affected we can start having blood loss into the uh stomach that may be noticed in traces of blood in any emesis or it may um discovered with evidence of old blood coming out with the stool as it moves through the GI tract so the first group of uh drugs we want to look at under the anti-ulcer is the classification for ant acids these are the most common they're over the counter uh can be a combination of calcium carbonate aluminum magnesium hydroxide um again these are the general over the counter um medications we'll get for upset stomach and heartburn and they're alkaline so we're looking at basic chemical reaction we're going to prod introduce an alkaline uh substance it's going to interact with the hydrochloric acid so we're going to neutralize those stomach acids it's going to elevate the pH in the stomach um also need to be aware that it's going to move on through the stomach into the in small intestines so it's also going to impact the pH in the body potentially a side effect or a secondary effect of the acids in this class is they will inactivate pepsin pepsin is necessary it's usually generated by the production triggered by the production of um hydrochloric acid and it's necessary for the digestion of protein so we may have a side of effects uh of poor digestion of proteins and so we just want to be aware of when we're taking it um we don't interfere with that process as well but again this main use is to just neutralize the acid so we're going to get symptom relief it's going to decrease that sense of heartburn that reflux and upset stomach so again we're just looking at symptom management by purely neutralizing the hydrochloric acid some things we want to watch out for then is if we're taking it with medications certain medications depend on that acidic level um or acidic nature of the stomach to be broken down so they can be used in the body so we're going to interfere with some medication actions by changing the pH of the stomach so as you're doing your drug research and you see on an acids check your other medications to see how do they react to a um increased pH in the stomach contents again these medications the alkaline nature of them that will also be absorbed into the small intestine and into our blood um blood circulation so we're going to have effects on our acid base chronic frequent use of an acids can create a metabolic alkalosis because again we're introducing excessive alkaline into the bloodstream as you notice from the generic names they have calcium and magnesium are often contents um of these an acids that gets absorbed so we may end up with some calcium level changes or magnesium effects we may affect some other electrolytes as well so again back to those General considerations we want to make sure the individual and their family understands the proper way to take the medications things to watch for that they're compliant but we also need to have that awareness of any alternative or um assist of tech treatments that they're using cuz again they may be taking some things that are just going to build on the actions of the an acids uh one home remedy would be um using sodium by carbon mixing that up in water and drinking that is doing the exact same thing as these an acids so we're getting that dual effect so we're going to have more of a risk for electrolyte imbalance and acid base imbalance the next class um that I want you to be aware of is H2 receptor antagonist so H2 is one of the histamine receptors uh when we've talked about histamine before it was primarily in terms of inflammatory process in the Airways and that was H1 where we see that one activated in um allergic reactions as well that um and just a general inflammatory process H2 receptors are in this lining of the GI tract and they are responsible for triggering the production of hydrochloric acid so this class of drugs um are going to block those H2 receptors so they can't be triggered that's going to decrease of hydrochloric acid production so this is going to be useful not just to neutralize basic symptoms but it's also going to be an effective treatment to slow the production of acid uh enable the body uh to go through the healing process hopefully more effectively in the case of gird PUD and with gird when that esophagus actually starts being eroded so erosive esophagitis things we want to watch out for again medication interactions because we are going to uh change the pH level of the stomach and that's also going to affect dadum and the beginning areas of the small intestine so by changing that pH that may change some medications Effectiveness another medication interaction we need to be aware of is the H2 receptor antagonist once they're in the bloodstream they will also combine with the cyp450 enzymes in the liver these are the enzymes that among other things are responsible for the breakdown or metabolism of certain drug classes so the H2 uh receptor antagonist will bind with those enzymes so they cannot so they're not available then to do the metabolism of the drugs that are coming through so we run a risk of having high levels of medication and circulation and the potential of getting into toxic levels or adverse reactions from uh too high of a um level of any of those certain medications in circul ation so again we want to be aware of that are the medications the individuals taking along with these H2 receptors are those medications dependent on the cyp 450 enzyme for their metabolism if so their doses may need to be altered all right considerations then are looking at again compliance compliance with timing relationship to drugs that they're taking and so we can decrease that interaction time uh we make sure kidney and liver functions are good I'm going to recommend a high fiber diet uh because one of the side effects of these drugs can be constipation so high fiber diet is going to help um reduce that potential and we also want to discourage smoking smoking uh just tends to interfere in general with histamine antagonist and make them less effective the next uh classification of anti-ulcer drugs would be the proton pump inhibitors or ppis so looking this case they are going to disrupt the processes of the cells in the stomach lining and inhibit the secretion of the hydrochloric acid these have a longer duration than the H2 inhibitors uh so they're going to be used for gird uh going to be used for Zing your Ellison which is a disease process that does cause excess of acid formation so again we're going to be using this to slow that uh production and secretion of hydrochloric acid again we have medication interactions that we're concerned about um prolonged use of um the ppis can result in hypomagnesemia so low magnesium levels in the blood so again this with prolonged juice so it's going to be one of the things that's going to be part of the follow-up assessments um proton pump inhibitors are especially when used in combination with any GI irritants which can be some food sources but particularly medications like the nids can increase the risk for GI uh bleeding um our nursing considerations the general ones we want to watch out for those GI irritant foods and drugs monitor for signs and symptoms of bleeding uh and make sure the individual and their family members know what to look for we can also uh treat ulcers uh with a mucosal protectant and this actually provides a protective covering for the ulcer that is already existing just uh as a medication it will coat that help protect that from the hydrochloric acid sort of replacing in a way those normal protectant um fluids and mucus is that the stomach uh produces so the purpose for this group is for the actual presence of ulcers uh does have a potential of developing some side effect of constipations we want to watch for that so we're going to be looking at U um high fiber diet plenty of fluid that type of thing it does uh potentially introduce some aluminum into circulation and if there's any kind of kidney failure that that aluminum may not be excreted so we have to watch for any any um of impact of having aluminum in circulation and normally that should not be there so we're going to be looking for kidney function um watching aluminum levels with this one since we're providing that coating for the stomach and the duum we want to time it so we take it on an empty stomach so it has a chance to coat the surface and it should be about an hour before or 2 hours after eating because we want all the digestive products out of the stomach so again when we take the medication can actually get right to the lining provided coating on the next video uh we're going to switch over and look at um the laxative classes as far as GI medications