PHARMACOLOGY FINAL EXAM REVIEW: STUDY GUIDE, EXAM PREPARATIONS - QUESTIONS AND ANSWERS, Exams of Pharmacology

Download PHARMACOLOGY FINAL EXAM REVIEW: STUDY GUIDE, EXAM PREPARATIONS - QUESTIONS AND ANSWERS and more Exams Pharmacology in PDF only on Docsity! PHARMACOLOGY FINAL EXAM REVIEW: STUDY GUIDE, EXAM PREPARATIONS - QUESTIONS AND ANSWERS Final Exam Review Remember to memorize normals (not all are listed): Serum potassium: 3.0-5.5 Serum digoxin: 0.5-2.0 ng/ml Serum creatinine: 0.8-1.4 Theophylline: 5-15 mcg/ml Dilantin: 10-20 mcg/ml Trough level for red man: 10-20 Patient teaching is important as a nurse. We need to explain to patients about self- monitoring. For example, a patient on digoxin needs to know how to check their pulse at the angle of their jaw for a full minute and know what to do if their HR is below 60. Patients need to be advised about drug interactions like if they are getting too much Tylenol in OTC and prescription medicines. Look at drug interactions for the exam. Medications safety is important. Remember the 6 rights of medication administration. If you look at the safety yellow box on page 69, it lists a lot of things to prevent medication errors. Certainly, when we administer medications, we want to do them in a quiet area, be aware of look alike sound alike drugs, make sure the order is written correctly, check label 3x. Pharmacologic principles Pharmacokinetics: what the body does to the drug. Absorption, distribution, metabolism, and elimination Bioavailability means the extent to which the drug is absorb. For example, drugs that are not very bioavailable usually need to be taken on an empty stomach like thyroid replacement drugs, but not all medicines have to be taken on an empty stomach, and often times, some medications can cause GI upset, so we tell patients that they can take the drug with a snack. After the drug is absorbed, it is distributed from the site of administration into the bloodstream, and when it enters the bloodstream, it binds to albumin. The liver is responsible for the creation of albumin. If our liver was sick, we would have a low albumin level or hypoalbuminemia. When people have hypoalbuminemia, it may be that they are malnourished that they have been sick for so long they haven’t been able to eat or lack of availability to food When the drug gets to the bloodstream and binds to the albumin. When it is bound to albumin, can it absorb its pharmacologic effect? No, it has to be uncoupled from the albumin to be able to get out of the bloodstream to get to it’s target organ or it’s activity. Patients with sick liver are not going to be protein-bounded very well or patients with low albumin Liver is mostly responsible for metabolism. Although there are different processes that can metabolize drugs, the ones we have talked about are the drug metabolizing enzymes, the CYP450 enzymes. They metabolize a lot of the drugs we take. Drugs that need those enzymes to metabolize are called the substrate of the enzyme. If you have a drug that is metabolized by a CYP450 enzyme and another drug that comes along, which is a CYP450 enzyme inducer, what will happen to the drug level of the first drug? There will be more enzymes and lower the therapeutic effect of the drug What are the two CYP450 inducers we studied? Lethargy Salivation What is the antidote for cholinergic toxicity? Atropine If atropine is the prototype anticholinergic drug, there are many other prescription and OTC drugs that have anticholinergic properties. 1st gen antihistamines not only block effect of histamine, but also have anticholinergic properties. Many of the antipsychotic also have anticholinergic properties. Antidepressants like amitriptyline (Elavil) that Granny in the case study was on also have anticholinergic properties. She got CNS changes like confusion, maybe to point of being psychotic. If we think about cholinergic stimulation to the cardiac conduction system does, it slows the HR, so if there’s symptomatic bradycardia, you give atropine, which is anticholinergic, which will bring the HR back up. If you have too much anticholinergic activity, you can have tachycardia. So, when there are CNS changes and tachycardia, what is the anticholinergic antidote? Physostigmine The Mnemonic for anticholinergic toxicity for the symptoms that we see are Red as a beet (cutaneous vasodilation) Dry as a bone (anhydrosis- means no sweating) Hot as a hare (anhydrotic hyperthermia- patient can’t sweat – temp- goes up) Blind as a bat (midriasis and loss of pupil contractility) Mad as a hatter (delerium; hallucinations) Full as a flask (urinary retention) Remember, if you have a problem in the Parasympathetic nervous system, don’t jump immediately to the Sympathetic nervous system to fix it. Stay in the same system. Why is physostigmine the drug of choice in anticholinergic toxicity? Physostigmine crosses the BBB whereas bethanechol doesn’t In the sympathetic nervous system, we got alpha and beta receptors Alpha 1 and 2 and Beta 1 and 2 (Review drug templates) Epinephrine stimulates alpha 1, beta 1, and beta 2. It is the drug of choice for cardiac arrest and anaphylaxis. Alpha 1 agonists. All decongestants, whether they are given topically onto the nasal mucosa or they are taken orally, they are all alpha 1 agonists. Beta blockers can be non-cardio selective or cardio selective. Cardio selective beta blockers block beta 1 only, which is predominantly in the cardiac conduction system Non-cardio selective will block beta 1 and 2, and beta 2 receptors are predominantly in the bronchial smooth muscle but are also in other places. We use beta blockers for a lot of things other than hypertension. We use alpha blockers when we want to help patients with both hypertension and hypotension (?), men with BPH. Alpha 1 blockers are extremely powerful. When do we tell the patient to take the alpha blocker? At bedtime because they will be laying down, they won’t be jumping up to go to the bathroom if they manage their prostate well. If somebody has full dose beta blockers, and they have to have cardiac stress test or allergy testing, they need to be off their beta blockers for 48 hours. Never ever stop beta blockers suddenly or stop them cold turkey, they need to be weaned off. Even if you, as the nurse, cannot be the one to make that decision, you can help the patient understand that they need to have that conversation with their physician. Alpha 2 agonists: prototype is clonidine, which is not one of the first drugs used for hypertension, but is very effective because it works in the CNS and you stimulate the alpha 2 receptor, it sucks the norepinephrine right back up into the pre-synaptic nerve terminal and it doesn’t allow the norepinephrine to be released to the peripheral tissues. That’s how it helps with hypertension. For the lipid drugs, we only needing statins. We got to remember when somebody is on a statin, they should not be taking any form of grapefruit because it is a CYP450 inhibitor. These drugs are really safe as millions of people are on them, but some people get muscle pain, and some people get really severe muscle pain, which is related to breakdown of the muscle, and release of the muscle protein into the bloodstream and that’s called myoglobin, and when it gets to the kidneys, it blocks up the renal tubules, and causes a condition called Rhabdomyolysis, and it will cause an acute kidney injury, which can go on to cause renal failure. Anemia. Remember about managing oral supplements. There are some people who cannot tolerate iron by mouth, they can’t absorb it, and so, they have to get IV iron. One of the products is called INFed or iron dextran, and it has the risk of causing anaphylaxis. So, we are very careful when we give INFed, we premedicate the patient with Benadryl. Because INFed can cause anaphylaxis, patients get a test dose, they get a 1 cc IV test dose of the INFed. The vital signs are taken before, frequently taken during, wait an hour before we give the rest of the dose. It is given on an infusion pump and it’s given over a couple of hours sometimes. What class of drug is Benadryl? 1st generation antihistamine we do, we would kill the patient, or they will flatline. When we give potassium IV or if it is given in a peripheral IV, it is mixed with diluted greatly and it is not given any faster than 10 ml equivalence per hour. If the person is in the ICU where they got a large, broad (?) IV in the central line, always the potassium no matter when you give it is in a pump, but in a central line on a pump in the ICU, we can use 20 ml equivalence per hour. Your pharmacist will have a fit if you try to give it in a peripheral vein faster than 10 milli equivalence per hour because it burns like hell, so its much better to give in a central line. Ace inhibitors are contraindicated, it’s preferable not to give it during pregnancy, but if the person is taking them and they are in the first trimester of pregnancy, they need to get off them because they are absolutely contraindicated in the second and third trimester of pregnancy. It can cause angioedema and anaphylaxis and the ace inhibitors can cause dry cough. So, what would you do if they have a dry cough? Switch to an ARB Why should we be careful that we don’t have hypokalemia when someone has digoxin? It will increase the risk of digoxin toxicity If somebody is already dig-toxic, they got too much digoxin in their system all those ATPase, things in the cell membrane, are all bound up with digoxin. Can the potassium get back in the cell? No, so the patient can have hyperkalemia if they are already dig-toxic With digoxin, nursing assessment is important, but mainly, we are concern of apical HR. Put the stethoscope on the chest and count for a full minute. It is important, especially in atrial fibrillation, because what you get in the apical HR will not be the same as what you get in the wrist, we say that atrial fibrillation is irregularly irregular What do we do if it is less than 60? Hold the drug and call the provider We would need to teach the patient to put two fingers up to the neck and count their own pulse to know what their own HR is. They need to self-monitor themselves as well. Nitrates (review) *Skipped to Anti-infectives, review everything else via templates and reviews* Anti- infectives Checking allergies, know their renal function because most anti-infectives are eliminated by the kidney except Ceftriaxone (Rocephin), which goes out in the bile, which is our 3rd generation cephalosporin. We need to know about if they do have a severe allergy to penicillin, we shouldn’t give them cephalosporins. If they have allergies to sulfur, we don’t want to give them non-steroidals or cox 2 inhibitors. Before we give an anti-infective, if the doctor has ordered the cultures, we get the culture before we start the antibiotic. Many antibiotics taken orally in women of child- bearing age who are on the birth control pill, the antibiotic will interfere with the estrogen and the birth control pills, so they need a backup form of contraception. We want to monitor patients of adverse effects or side effects in antiinfectives. They can be as mild as nausea, vomiting and diarrhea, but side effects go away when you stop the drug. If somebody has an allergic reaction that involves the immune system that might include an itchy rash, stop the drug and it gets better. It can be serious like anaphylaxis. That’s why they are given IV or IM injections of antibiotics, we hold the patient for 30 minutes to make sure they don’t go out into the parking lot and have anaphylaxis. We monitor IV sites if we are giving anti- infectives by an IV route. We don’t want the vein to get inflamed and we don’t want the antibiotic to out in the tissue. Sometimes when we are giving really broad spectrum anti-infectives, patients can get super infections like C-diff diarrhea, which is an antibiotic-associated pseudomembranous colitis that can be lifethreatening to some patients. What is the drug of choice for C-diff? Vancomycin. It is FDA-approved drug of choice for C-diff. This is basically the only time you will see vancomycin given orally because it will be put into the bowel and come in contact with the toxin What if the vancomycin doesn’t work for C-diff? fidaxomicin (Dificid) is the next drug of choice For many years, people used flagyl for C-diff. IS it FDA-approved? No Most of the time, vancomycin will be given IV for MRSA (Methicillin-resistant staph aureus). Over what period of time should vancomycin be administered? It needs to be given over 60-90 minutes. Why? Red man syndrome, which is when someone gets flushed up in the neck, chest, and face and get hypotensive. Is this an allergy? No, it is histamine release. The nurse has administered it too fast What is the other super infection, for example when patients will receive penicillin they will think that they will get candida (yeast), which can be in the mouth, esophagus, vagina, and if we don’t take care of the lines properly, they can get it in the blood. PCP or PJP pneumonia occurs in immunosuppressed patients who have AIDs. To prevent it, patients get Bactrim (prototype), the Sulfamethoxazole/trimethoprim, 2-3x a week. When we just talk about the usual super infections, we are talking about C-diff diarrhea or yeast infections level is too high, that means the dose needs to be reduced or the dosing interval needs to be widened. Thyroid drugs, remember that the antithyroid drugs, PTU and methimazole, they are class D for pregnancy, but if the person has to have them when they are pregnant, they get the propylthiouracil, the PTU in the first trimester, and the methimazole in the second and third trimester Parkinson drugs (review) Look at GI medications Tagamet is a CYP450 inhibitor. Those are H2 blockers H1 are the antihistamines, those are the H1 blockers H2 blockers are drugs that block the histamine receptor on the parietal cell in the gastric brain (?) and they prevent some acid from being form in the acid. The most powerful ones are the proton pump inhibitors like Prilosec. Zantac, Pepcid, and Tagamet are the H2 blockers and Prilosec is the prototype PPI. Promotility agent was talked with nausea that helps things move through in the right direction. Prototype is metoclopramide (Reglan) and it depresses dopamine Laxatives, often times in the hospital, you will get an order for. Anything with magnesium in it will increase the frequency of bowel movements. After a surgery, we don’t want people sitting on the toilet straining to have a bowel movement, so they will be given a stool softener. If people have acute shortterm constipation, they may be given a stimulant laxative like Dulcolax, which can be given as a pill or suppository. If we have to give something to clean the colon out before a colonoscopy, we need something not going to make you go lightly, it is called GoLytly and another is called Su Prep. The point is the colon has to be clean as a whistle, so the doctor can get the scope all the way to the ilia secum valve. How do you know you have done a good job, or you clean the colon out? The patient won’t know if they are peeing or pooping, the stool should be clear, transparent, or yellow MiraLAX is fairly gentle, it is available OTC, and it can be used and mixed with any fluid If nothing has work and we have to blow them out, we can use lactulose, and that is a man made sugar, and it is very useful for somebody who is just really stuck, can’t go to the bathroom. It is also used in people with liver failure. In liver failure, people have an elevated serum ammonia level and the lactulose brings that down. For diarrhea, we got the quicker picker upper like cholesyramine and for example, if we need to give something to stop diarrhea, we have OTC diarrhea medicines like Immodium and prescription drugs like Lomotil. They both contain a small amount of opioid and an atropine- like drug. Remember preoperatively, if someone has to have surgery, we sometimes get an order as atropine for a premed. That will slow down peristalsis and GI secretions and that’s why there is a little opioid, but also an atropine like medicine in those anti-diarrheals. We know there are some chemotherapy drugs that cause profuse diarrhea and so, we give sometimes atropine as a premed to those patients and give immodium and Lomotil to alternate to help with diarrhea. Opioids can cause constipation as well, which can slow down diarrhea. Anybody who is put on an opioid needs to be put on a bowel mover that involves stool softeners and laxatives because we don’t want them binding all those mu receptors and having all those anticholinergic activity that opioids can cause, so they need to all be on a bowel program. Antiemetics (review)