My Nursing Mastery

Med Rec Review: HTN

November 26, 2018 Higher Learning Technologies
My Nursing Mastery
Med Rec Review: HTN
Show Notes Transcript

Today we're going to be reviewing the most common medications used to treat hypertensions in adults.  With Cindi Bell RN, BSN

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***=might show up on the NCLEX

Cindi:

Hey everyone, welcome to our med rec review. Today we're going to be reviewing the most common medications used to treat hypertension in adults. Medication reconciliation or med rec is performed during transitions of care during any handoff, and they're an important part of nursing responsibility both in the acute and long term care and home setting and in the office at follow-up appointments as well. The patient's usual medication list is reviewed and recorded accurately. This provides continuity of care and it prevents medication errors and let's not forget that it provides a great opportunity to provide teaching to caregivers and patients. As with our other podcasts, when you hear this sound,(ding)*** pay special attention to this key point for the NCLEX. Today we're going to talk about hypertension meds and these are medications that you will see in your everyday practice over and over again. They are the most common medications you will see on adult medication lists and they are prime targets for questions that you will see on the NCLEX. Most adults with hypertension have primary hypertension, so this used to be called essential hypertension. This type of hypertension doesn't have a known cause. The other type of hypertension which is less common is secondary hypertension. This means that elevated blood pressure results from another cause often this is from a kidney problem. Drugs chosen to treat hypertension are often selected for the patient based on what else they have going on because these drugs have other uses such as their antiarrhythmic effects. This will make sense once we discuss the specific agents so let's get to it. First, let's talk about some general guidelines for hypertension medications, which are often cardiac medications. First, the directions on how and when to take these are aimed at decreasing unwanted effects such as dizziness, which is the most common effect, um, adverse effect of these medications. Patients may be instructed by the provider to take them at bedtime, for example. This is a pretty common instruction so that patients don't notice the dizziness during the daytime. Second, be aware of trends in blood pressure and heart rate. Those are the two most important parameters that you have to pay attention to, especially when people first start taking these medicines.***Also be aware of fluid status, especially when you're treating someone acutely in the hospital. Always ask yourself what the kidneys are doing and whether there are signs of low cardiac output such as a cough or dyspnea on exertion. Does the patient have adequate output or any changes in output? Have they been having to elevate their head to lay flat and sleep at night, and is this new? Those are all key questions to be asking. Most of these drugs can affect the liver and renal function, so make sure you check those labs. The top choices for treating hypertension initially are thiazide diuretics, ace inhibitors, and CCB's or calcium channel blockers. It is very common for most patients to be taking more than one class of medications, and the reason is, although taking one drug also called monotherapy works well for mild hypertension, higher blood pressures will require more than one agent. The way it works is the provider will trial medication, evaluate the results, and then add on if needed, so expect to see many of these medications in your nursing travels. The first, and a very important class of medications, are ace inhibitors. These are angiotensin converting enzyme inhibitors. An example that is commonly used is Lisinopril. How do these drugs work? They inhibit the enzyme involved in regulating blood pressure specifically by blocking the formation of angiotensin ii. This is a potent vasoconstrictor, so if they block a vasoconstrictor, then they result in vasodilation. These drugs act on the kidneys to reduce sodium retention, the excretion of sodium and water results, so you get reduced fluid volume, reduced preload and after load for the heart and decreased vascular resistance. The result is diarrhesis. These are often first line agents used for hypertension,***but they're especially helpful for patients who have congestive heart failure and after a heart attack in order to reduce the workload on the heart. So let's go over some nursing interventions and things to be keenly aware of and teach your patients. Ace inhibitors retain potassium. They have the potential to increase serum potassium if the patient is taking in extra potassium. So you want to tell patients to avoid using any salt substitutes over the counter that have added potassium. The other thing that complicates serum potassium for ace inhibitors is adding a potassium sparing diuretics such as spironolactone. Relatively common side effects for ace inhibitors includes general fatigue, dizziness, especially when first starting therapy, mood changes, headache and impaired taste, Orthostatic hypotension or getting dizzy and hypotensive when you stand up is very common amongst all the classes, but is especially common with the classes that cause diarrhesis. So you want to caution patients when they take hot showers not to change position too quickly or that they may become dizzy or feel faint after a really hot shower, so they want to be sure to drink adequate fluids and stay hydrated. Providers will often prescribe these medications to take at bedtime to lessen these symptoms. Angioedema is a serious adverse effect that can occur while taking ace inhibitor medications. Angioedema is swelling of the face, lips, larynx, tongue, and extremities, and it can be life threatening. It can come on suddenly. This is something that can occur with this class of medications. You want to also tell patients to keep these and other antihypertensives out of the reach of children. And this class should not be taken during pregnancy or while breastfeeding.***A very common adverse effect is a persistent dry cough. And if this happens, they should discontinue the medication with their doctor's permission. It's believed to be the result of its actions on bradykinin. Symptoms resolve once the drug is discontinued. So often the provider will find a substitute. There is recent research that shows an interaction between medications that act on the kidneys and NSAID's like Ibuprofen. Concurrent use can reduce renal function, especially in older adults with hypervolemia. The provider may choose to check renal functions more frequently for this population.***For lab work, always review renal functions before beginning therapy for ace inhibitors, and periodically thereafter. Okay, we're going move on to a class that's related to ace inhibitors and they are called ARB's. An example would be losartan and ARB stands for Angiotensin ii receptor blocker. They're actions are similar to ace inhibitors by blocking angiotensin ii directly resulting in vessel dilation. Specific uses are for hypertension, heart failure, and also after a heart attack to reduce workload similar to ace inhibitors. So adverse effects are very similar to ace inhibitors. And you want to give the same precautions regarding potassium supplements and potassium sparing diuretics, presenting a risk for elevated blood potassium and the risk for decreased renal function if they are taking an NSAID. In addition, lithium levels can rise and toxicity can occur. Although angioedema is possible, it's less common with this class. These drugs are often the next choice for patients who have developed a chronic cough on an ace inhibitor. As we discussed earlier, patients are not typically prescribed both an ace and an ARB since they have the same actions and patients taking both are at increased risk for hypertension and renal problems. Okay, now we're going to move on to a very common class of medications that has a different mechanism of action.***These are Beta blockers an example would be lopressor. They are used for hypertension, angina, post-myocardial infarction, and they may be used for rate control for atrial fibrillation. Aside from being a class two anti-dysrhythmic that slows AV conduction, these drugs are Beta one adrenal receptor blocking agents. They are found primarily in cardiac muscle. Some agents are less cardioselective, we call these nonselective. They stimulate Beta one and Beta two receptors, Beta one being in the heart and Beta two primarily in the lungs. Those can generate more unwanted side effects like bronchial restriction. For that reason, they're avoided in patients with asthma. This is due to the potential for the Beta activity in the lungs affecting receptors and causing bronco constriction. Although there is a lot of debate and research to determine whether the drug should be withheld from those with asthma, this is a pretty common precaution. Beta blockers are generally not the first choice for hypertension. They decrease heart contractility, they decrease oxygen demand, and they increase oxygen getting to the myocardium, so they are very useful for certain patients. They slow the heart rate and they shouldn't be used for patients with a heart block for the same reasons we should use caution for any patients with heart failure were cardiac output might be reduced further as the heart rate slows from the effects of the medication. Also, for those patients with severe peripheral artery disease, we want to exercise caution because the decreased cardiac output can affect distal circulation as well. Some more precautions for Beta blockers for those with thyroid disease or even diabetes. Beta blockers can mask illness and symptoms of illness such as tachycardia.***Symptoms of hypoglycemia can be unnoticed because Beta blockers will blunt tachycardia. So some key nursing points: patients should not stop beta blockers suddenly, the provider will often taper the dosing over one to two weeks to prevent any worsening angina, if they have angina. Medication interactions can arise from a rebound. Hypertension. Beta blockers suppressed the heart rate and when they're removed, this creates a sudden increase in heart rate.***Patients will often complain of strange dreams or nightmares or even insomnia while taking this medication. Teach patients to take it before meals. Tell patients they may tire more easily when they exercise, but they should report any shortness of breath.***It is very important for both nurses and patients to check a radial pulse for one minute before dosing and notify the provider if the heart rate is under 60 beats per minute. Common side effects are general fatigue and low energy due to the decreased cardiac output. I have often heard this from patients that I have worked with. Exertional angina, having symptoms when the demand for oxygen by the heart is high can occur in susceptible patients or patients who have undiagnosed coronary artery disease or ischemic disease. Patients with angina and CHF, especially those taking digoxin should have these drugs prescribed with caution. Nurses should be aware of symptoms of Beta blocker toxicity which include bradycardia, shortness of breath, hypotension, and weight gain over two pounds in a week indicating CHF as well as a cough, decreased output, palpitations, and feeling faint. These drugs are pregnancy category"C" slightly better than the other two classes we talked about. This means that the benefits should outweigh the risks if it's prescribed. Category C drugs usually lack enough evidence and studies to support their use in any case. For lab work, these drugs may affect lipid levels and glucose depending on the agent. Okay, next class, calcium channel blockers or CCB's, an example would be deltasone. These drugs are also anti-dysrhythmic, and anti-anginal, and they're commonly used for rate control for a-fib, probably more common than Beta blockers.***As with Beta blockers, always check blood pressure and a radial pulse before administering CCB's. Calcium channel blockers act on cardiac and smooth muscle in vessels. They bind to calcium, preventing calcium movement, and this results in relaxed muscle tissue and creates a moderate lowering of blood pressure. They're popular uses are for angina. They are potent vasodilators, so they're useful for coronary artery spasms. This can increase exercise tolerance by decreasing the work the heart must do. These agents are used for patients with hypertension that require this drug for the other mentioned issues such as a-fib, but they may be preferred for patients with obstructive lung disease as well. Precautions include, as with other hypertension medications that alter conduction in the heart, this drug should not be given to patients with higher level heart blocks or things like sick sinus syndrome, a sinus node that isn't functioning properly. Unless they already have a working pacemaker they should also be avoided after an acute heart attack or for heart failure. Key nursing points or teaching for patients is to report any chest pain, to report any heart rate under 50 beats per minute, any headache, nausea or vomiting, rash or edema or weight gain. The effects are cumulative when patients take other medications that affect cardiac contractility, most notably Beta blockers or digoxin, so providers will titrate dosing because calcium channel blockers combined with similar drugs can lead to heart failure. The next class of medications are diuretics and there are various types. These drugs are used to decreased plasma and extra cellular fluid volume. In turn, they decrease the workload of the heart, including preload. They all work by limiting the resorption of sodium in some portion of the kidney tubules. A few classes of diuretics are particularly important. Loop diuretics such as furosemide or Lasix, are perhaps the most effective drugs to reduce circulating fluid volume. They result in profound diaeresis. These drugs act in the kidney tubules at the loop of Henley, and that's a good way to remember the name of this class: loop diuretics. This is where a lot of sodium is reabsorbed. This type of drug causes sodium to be excreted, which in turn takes free water with it, reducing fluid volume. Common problems to watch for are hypovolemia and electrolyte imbalances. Renal failure can occur due to the decreased blood volume in the kidneys. It's important to keep the patient hydrated enough to keep the kidneys working. Circulatory collapse can actually result, especially in older adult patients with vulnerable kidneys. This is a concept that's important to understand. Many nurses wonder why we give Iv fluids to patients with CHF that are also being diuresed. It seems like it doesn't make sense, but many times nursing isn't just about fluid reduction, but getting fluid in the right places in the body to restore balance. Another important class that is used as first line or second line agents for hypertension are thiazide diuretics, the most popular is hydroclorothiazide. Their action is also in the kidney, but in the distal tubule. It has the same effect on excreting sodium, but to a much lesser extent than loop diuretics, not quite as potent. A third class that you'll see often are potassium sparing diuretics, like spironolactone. These act in the collecting tubule because they spare potassium excretion, they are often used in small doses in addition to the other diarrhetics to limit potassium loss. So there are some precautions specifically for loop diuretics like lasix.***The first is check output: loop diuretic should not be given to patients with inuria or no urination or to patients with severe urinary obstruction. They should also be avoided in patients who may suffer complications from extreme fluid shifts. An example would be a patient with ascites from liver cirrhosis. Lasix's can cause damage to hearing called auto-toxicity, but this is a bigger risk when patients are taking certain medications that interact such as certain antibiotics and it's relatively rare.***There is significant risk for toxicity when patients are taking digoxin. So watch for signs of digoxin toxicity including anorexia, visual changes, nausea, vomiting, and bradycardia. Okay, so some general guidelines with diuretics. Most adverse effects will occur in the first few weeks of therapy. For diabetes diuretics can increase glucose concentration.***Anytime you diurese you can deplete potassium, so check potassium levels and be alert for symptoms of decreased potassium such as leg cramping and weakness. Due to the action on fluid volume these drugs can cause severe hypovolemia in those taking lithium. Some key nursing points are instruct patients to get in the habit of weighing themselves daily. Take these drugs in the morning because of the need to urinate within one to two hours after.***Because patients will need to get to the bathroom, evaluate their mobility and their risk for falls. Teach patients how to monitor their blood pressure and always check lights and kidney functions like BUN on a regular basis. The last two groups we're going to talk about our Alpha-agonists, and Alpha-blockers. The first group is central Alpha-agonists. These are more commonly used in acute care to treat severe hypertension. These drugs have a rapid response. Even when taken orally, they respond within an hour. They are commonly used for hypertensive crisis, so nurses should know the symptoms of hypertensive crisis, including diaphoresis, anxiety, tachycardia, salivation, and abdominal pain and general muscle pain. A common example is clonidine. These drugs directly act centrally in the brain stem by decreasing sympathetic activity from the CNS. They result in lower heart rate and blood pressure, but they have little effect on postural hypotension like other medications we mentioned, so the symptoms of dizziness are usually less. They do affect the heart rate, so you want to avoid these medications when there's a heart block and use caution with patients taking other drugs that affect conduction, such as calcium channel blockers. Some key nursing points: dosage strengths for the most common drug, which is clonidine, are very small, zero point one to zero point two milligrams per dose, but they result in very potent effects so patients should not discontinue this drug. Suddenly, they may experience withdrawal symptoms including severe hypertension. A weekly transdermal patch is also available. This drug may have sedative effects in addition to dizziness, so you have to caution patients about driving after starting the drug and teach them to avoid alcohol. It is not recommended in older adults over the age of 65 as a first choice. Common side effects are similar to ace inhibitors, but especially include dry eyes for contact lens wearers, dry mouth and constipation. Clonidine is a pregnancy category C drug, and it is passed on in breast milk. There are a number of drug interactions, but one in particular, Methyldopa should require the nurse to check liver function tests. The last category we're going to talk about our vasodilators, Alpha One blockers. Similar to the last category, they act directly on arterial smooth muscle controlled by the sympathetic nervous system. This results in dilated blood muscles. Examples of these types of medications are hydrazine, doxazosin, and terazosin.***This class of medications is often used for bph: benign prostatic hypertrophy. As with the other medications, patients should weigh themselves daily, monitor their blood pressure, and report any shortness of breath, chest pain, or cough. These agents aren't very commonly used for hypertension unless the patient has bph. Some of the agents may increase the risk for Lupus. Ask patients to report any fever, sore throat, joint pain or fatigue. This concludes this edition of our med rec review. If you have any suggestions for future additions, please don't hesitate to get in touch with us and for more tips to master the NCLEX and more podcasts go to nclexmastery.com.