all right platelets we are now talking about platelet aggregation inhibitors or anti-platelet agents is how you want to remember that this is in chapter 26 page 404 mechanism of action for selected agents so what we want to remember about these um these don't work these particular drugs don't actually work on what's called the clotting cascade they basically prevent there's different pathways of coagulation okay what these basically do is just prevent platelet adhesion at the site of the blood vessel injury okay so that actually occurs before the clotting cascade occurs so you just want to remember it as prevents platelet adhesion at the site of blood vessel injury so it works in the cycle oxygenase or otherwise known as cox pathway in the platelets so we have what's called cox1 and cox2 these are just different enzymes they actually activate prostaglandins prostaglandins are inflammatory mediators and those inflammatory mediators um basically systemically what you see is pain and fever so cox one happens to be um it's produced by prostaglandins that actually activate platelets okay so it works in the cox-1 pathway basically in platelets so really what you want to remember is it just inhibits um platelet aggregation that's the biggest take back from that i know that's a lot of wordiness um might sound like a complicated pathway to remember but what you want to know is it works on the cox pathway and it basically inhibits platelet aggregation so when i say it inhibits platelet aggregation what i'm saying is it prevents platelet adhesion so it's preventing all those platelets from clumping together what's the danger of that well depending on your patient's medical history if they have history of mi they have a trifecta of issues right history of high blood pressure history of high cholesterol they're more at risk for some type of cardiac event so if they have these platelets that can aggregate and clump together these platelets might actually block a major vessel like in the coronary artery and then we have an ischemic event um adp inhibitor prevents platelet membrane from receiving signal to aggregate so that's basically the how right the mechanism of action therapeutic effect inhibits platelet aggregation and that's really how you want to remember this okay indications would be coronary artery disease we looked at that coronary artery a little bit ago myocardial infarction or mi in a thrombotic stroke meaning it's a clot that actually caused that stroke precautions would be bleeding right concurrent use with some proton pump inhibitors or ppis when we get to gi you'll learn more about that um some medications like clopidogrel you're going to learn about that's one of these classes of drugs that's a um platelet aggregation inhibitor if a patient is taking a ppi or a proton pump inhibitor and clopidogrel it can actually interfere with the activation of that drug and so it'll decrease the anti-platelet effects of clopidogrel contraindications would be active bleed gi ulcer recent hemorrhagic stroke so hopefully the why and how is making sense to you so if i'm preventing the platelets from aggregatings right i'm preventing those platelets from clumping and sticking together right if they don't do that if i have a site of injury what's going to happen i'll be more at risk for bleeding so um we talked about active bleeding and then thrombocytopenia is also another contraindication so thrombocytopenia is low platelets so if we already have low platelets and then we're preventing them from any adhesion from taking place then we're going to be at more risk for bleeding side effects would be active bleeding obvious or occult obvious is blood you can actually see with your eye occult is you could not see it unless you put it underneath the microscope or used a solution on it to show that it there is actually blood same in the stool so occult is not by the human eye obvious is again thrombocytopenia low platelets and gi upset so as the nurse we're going to make sure that we're monitoring for bleeding and think about the places that you would see bleeding right not just in their stool not just in their urine but think about even the smallest places maybe around their iv site is bleeding maybe when they brush their teeth their gums bleed right so think about all the different areas that a patient completely really want to pay attention to that we're going to follow their cbc hemoglobin hematocrits and platelets and then patient education we're going to educate them about the drug side effects symptoms of bleeding and the interaction examples of drugs in class so aspirin that's a prototype you need to know may be written as asa remember the farm class is an inset or salicylate but it also fits in this particular class as well because it has anti-platelet aggregation effects and then called plena girl clopidogrel's is a big one you need to remember from this class that is an anti-platelet adjective um agent that's the therapeutic class and then his farm class would be platelet aggregation inhibitor so