{"id":316,"date":"2019-12-08T22:29:21","date_gmt":"2019-12-09T03:29:21","guid":{"rendered":"https:\/\/opentextbc.ca\/nursingpharmacology\/chapter\/6-10-antihypertensives\/"},"modified":"2022-12-13T17:16:18","modified_gmt":"2022-12-13T22:16:18","slug":"6-10-antihypertensives","status":"publish","type":"chapter","link":"https:\/\/opentextbc.ca\/nursingpharmacology\/chapter\/6-10-antihypertensives\/","title":{"raw":"6.10 Anti-hypertensives","rendered":"6.10 Anti-hypertensives"},"content":{"raw":"

Antihypertensive Medications<\/h1>\r\nMany different medication classifications are used to treat [pb_glossary id=\"795\"]hypertension[\/pb_glossary]<\/strong>. It is important to understand the different mechanisms of action for different classes of anti-hypertensives because clients are often on a combination of medications that work synergistically to manage blood pressure. These medications are also discussed in the \"Autonomic Nervous System\" chapter, with more information provided regarding the specific receptors they affect.\r\n

Alpha-2 Agonist<\/h2>\r\nClonidine<\/a> is an Alpha-2 agonist. You can read more information about Alpha-2 agonists in the \"Autonomic Nervous System\" chapter.\r\n

Mechanism of Action<\/h3>\r\nClonidine stimulates the alpha-adrenergic receptors, resulting in vasodilation and decreased blood pressure, thus decreasing peripheral resistance, increased blood flow to the kidneys, and decreased afterload.\r\n

Indications for Use<\/h3>\r\nClonidine is used to treat hypertension and ADHD.\r\n

Nursing Considerations Across the Lifespan<\/h3>\r\nMonitor BP and pulse rate. Dosage is usually adjusted to the client\u2019s blood pressure because it can cause hypotension, bradycardia, and sedation. Rebound hypertension may occur if stopped abruptly.[footnote]This work is a derivative of Daily Med<\/a> by U.S. National Library of Medicine<\/a> in the public domain<\/a>. [\/footnote]\r\n

Client Teaching & Education<\/h3>\r\nClients should be compliant with medication therapy and take the medication at the same time each day.\u00a0 They should be careful not to take more than the prescribed dose within a 24-hour period, or abruptly cease medication, as rebound hypertension might occur. Medications may cause orthostatic changes, so individuals should change positions slowly.\u00a0 Additionally, medications may cause dry mouth and dry eyes.\u00a0 Individuals should also avoid the use of alcohol and other CNS depressants while taking these medications.[footnote]uCentral from Unbound Medicine. https:\/\/www.unboundmedicine.com\/ucentral<\/a>[\/footnote]\r\n

ACE Inhibitor (Angiotensin Converting Enzyme)<\/h2>\r\nCaptopril is an example of an ACE (angiotensin converting enzyme) inhibitor.\r\n

Mechanism of Action<\/h3>\r\nThis medication blocks the conversion of Angiotensin I to Angiotensin II in the renin-angiotensin-aldosterone system. This will lead to vasodilation and sodium and water excretion by blocking aldosterone. See more information about the renin-angiotensin-aldosterone system in the \u201cReview of Basic Concepts\u201d section of this chapter.\r\n

Indications for Use<\/h3>\r\nCaptopril is used to treat hypertension and heart failure. This medication also helps reduce diabetic nephropathy.\r\n

Nursing Considerations Across the Lifespan<\/h3>\r\nDo not administer to clients who are pregnant. Use with caution with clients who have diabetes.\r\n\r\nAvoid use with other medications that increase potassium. This medication may increase risk of lithium toxicity.\r\n

Adverse\/Side Effects<\/h3>\r\nBlack Box Warning: Clients who become pregnant should discontinue this medication due to the risk of fetal harm or fetal death.\r\n\r\nClients taking this medication may experience hypotension, cough, hyperkalemia, increased risk of infection, angioedema, anaphylactoid reactions, or proteinuria. Clients who experience increased facial swelling or difficulty swallowing or breathing should seek emergency medical attention. Report a persistent cough or angioedema to the health care provider.[footnote]This work is a derivative of Daily Med<\/a> by U.S. National Library of Medicine<\/a> in the public domain<\/a>. [\/footnote]\r\n

Client Teaching & Education<\/h3>\r\nMedications should be taken as directed.\u00a0 Clients taking ACE inhibitors should be cautioned to avoid salt substitutes or foods high in potassium.\u00a0 Additionally, the medication may alter the sense of taste, but this generally resolves within 2-3 months of medication therapy.\r\n\r\nClients taking ACE inhibitors may also experience a persistent cough throughout the duration of medication therapy.[footnote]uCentral from Unbound Medicine. https:\/\/www.unboundmedicine.com\/ucentral<\/a>[\/footnote]\r\n

Angiotensin II Receptor Blocker (ARB)<\/h2>\r\nLosartan is an example of an Angiotensin II receptor blocker, also referred to as an ARB. ARBs are similar to ACE inhibitors in that they act on the renin-angiotensin-aldosterone system (RAAS). However, the difference is that they block Angiotensin II and cause vasodilation and decreased peripheral resistance, but are not likely to cause the cough that ACE inhibitors can.\r\n

Mechanism of Action<\/h3>\r\nLosartan blocks Angiotensin II in the renin-angiotensin-aldosterone system to produce vasodilation.\r\n

Indications for Use<\/h3>\r\nARB is used to treat hypertension and to prevent nephropathy in diabetic clients.\r\n

Nursing Considerations Across the Lifespan<\/h3>\r\nDo not administer to clients who are pregnant. It is not recommended for children under 6. Anticipate dosage adjustment with hepatic impairment. This drug can cause renal impairment and hyperkalemia.\r\n

Adverse\/Side Effects<\/h3>\r\nBlack Box Warning: Clients who become pregnant should discontinue this medication due to the risk of fetal harm or fetal death.\r\n\r\nClients taking this medication may experience hypotension, dizziness, increased risk of infection, angioedema, or proteinuria. Clients who experience increased facial swelling or difficulty swallowing or breathing should seek emergency medical attention.\r\n

Client Teaching & Education<\/h3>\r\nMedications should be taken as directed, at the same time each day. Clients should not discontinue therapy unless directed to do so by their healthcare provider.\u00a0 Patients should be careful to avoid salt substitutes and foods with high levels of potassium. ARBs may cause orthostatic changes and patients should be cautioned to change positions slowly.[footnote]uCentral from Unbound Medicine. https:\/\/www.unboundmedicine.com\/ucentral<\/a>[\/footnote]\r\n
Clinical Reasoning and Decision-Making Activity 6.10\r\n\r\n\"Image<\/header>\r\n
\r\n\r\nA male 65-year-old client has the following medications ordered: metoprolol succinate 100 mg daily, lisinopril 5 mg daily, verapamil ER 100 mg daily, and hydrochlorothiazide 25 mg daily. He has a history of hyperlipidemia, hypertension, and coronary artery disease. The client asks the nurse, \u201cWhy do I have to take so many medications?\u201d\r\n
    \r\n \t
  1. What is the class and mechanism of action of each of these medications?<\/li>\r\n \t
  2. What is the nurse\u2019s best response to the client's question?<\/li>\r\n<\/ol>\r\nNote: Answers to the Clinical Reasoning and Decision Making Activities can be found in the \"Answer Key<\/a>\" sections at the end of the book.\r\n\r\n<\/div>\r\n<\/div>\r\n

    Vasodilator<\/h2>\r\nHydralazine is an example of a direct vasodilator.\r\n

    Mechanism of Action<\/h3>\r\nHydralazine\u2019s direct mechanism of action is unknown, but it causes vasodilation via direct relaxation of vascular smooth muscle. Peripheral vasodilation results in a reduction of blood pressure and decreased vascular resistance, resulting in increased cardiac output.\r\n

    Indications for Use<\/h3>\r\nVasodilators are used to treat hypertension.\r\n

    Nursing Considerations Across the Lifespan<\/h3>\r\nUse with caution in clients with coronary artery disease, mitral valve rheumatic heart disease, and cerebral vascular accidents.\r\n\r\nThis medication should only be used in pregnancy if the benefits outweigh the risks, due to lack of safety studies.\r\n

    Adverse\/Side Effects<\/h3>\r\nClients should be monitored for infection and are at risk of developing systemic lupus erythematosus (SLE). SLE is a chronic disease that causes inflammation in connective tissues. The signs and symptoms of SLE vary among affected individuals and can involve many organs and systems, including the skin, joints, kidneys, lungs, central nervous system, and blood-forming (hematopoietic) system. A characteristic sign of SLE is a flat, red rash across the cheeks and bridge of the nose. This rash is called a \"butterfly rash\" because of its shape.\r\n\r\nHypotension, palpitations, angina, tremors, numbness, tingling, disorientation, nasal congestion, headache, nausea, vomiting, and diarrhea are effects associated with hydralazine.[footnote]This work is a derivative of Daily Med<\/a> by U.S. National Library of Medicine<\/a> in the public domain<\/a>. [\/footnote]\r\n

    Client Teaching & Education<\/h3>\r\nClients should remain compliant with the therapeutic dosing regimen, even if symptoms resolve. The client should be cautious not to double up on medication doses.\u00a0 Additionally, the client should consult the healthcare provider for follow-up instruction if two or more doses of medication are missed.\u00a0 Clients should be instructed to monitor their weight and assess for fluid retention in the feet and ankles.\u00a0 Additionally, the medication can cause side effects of orthostatic hypotension and drowsiness.[footnote]uCentral from Unbound Medicine. https:\/\/www.unboundmedicine.com\/ucentral<\/a>[\/footnote]\r\n

    Beta-1 Antagonists<\/h2>\r\nMetoprolol<\/a> is a selective Beta-1 blocker. You can read more information about Beta-1 antagonists in the \"Autonomic Nervous System\" chapter.\r\n

    Mechanism of Action<\/h3>\r\nMetoprolol primarily blocks Beta-1 receptors in the heart, causing decreased heart rate and decreased blood pressure. However, higher doses can also block Beta-2 receptors in the lungs, causing bronchoconstriction.\r\n

    Indications for Use<\/h3>\r\nMetoprolol is commonly used to treat high blood pressure, chest pain due to poor blood flow to the heart, and several heart conditions involving an abnormally fast heart rate. It is used as an early intervention during myocardial infarction (MI) to reduce the workload of the heart.\r\n

    Nursing Considerations Across the Lifespan<\/h3>\r\nER formulations should not be crushed. Assess the client\u2019s apical pulse rate before administering; if it is less than 60 beats\/minute, withhold the drug and call the prescriber immediately, unless other parameters are provided. In diabetic clients, monitor glucose level closely because the drug masks common signs and symptoms of hypoglycemia.\r\n

    Adverse\/Side Effects<\/h3>\r\nThe most serious potential adverse effects are shortness of breath, bradycardia, and worsening heart failure. Other adverse effects include fatigue, dizziness, depression, insomnia, nightmares, GI upset, erectile dysfunction, dyspnea, and wheezing. Black Box Warning: When stopping therapy, taper dosage over 1 to 2 weeks because abrupt discontinuation may cause chest pain or MI.[footnote]This work is a derivative of Daily Med<\/a> by U.S. National Library of Medicine<\/a> in the public domain<\/a>. [\/footnote]\r\n

    Client Teaching & Education<\/h3>\r\nClients should be compliant with medication therapy and take the medication at the same time each day.\u00a0 Do not abruptly cease medication, as arrhythmias, hypertension, or ischemia may develop.\u00a0 Clients and their families should be instructed to check pulse and blood pressure and report abnormalities to the healthcare provider.\u00a0 Additionally, these medications may cause side effects of dizziness and cold sensitivity.[footnote]uCentral from Unbound Medicine. https:\/\/www.unboundmedicine.com\/ucentral<\/a>[\/footnote]\r\n

    Metoprolol Medication Card<\/h1>\r\nNow let's take a closer look at the medication card for metoprolol in Table 6.10.[footnote]This work is a derivative of\u00a0Daily Med<\/a>\u00a0by\u00a0U.S. National Library of Medicine<\/a>\u00a0in the\u00a0public domain<\/a>. [\/footnote] Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication.\r\n
    \r\n

    Medication Card 6.10.1: Metoprolol<\/h2>\r\n<\/header>\r\n
    \r\n\r\nClass: <\/strong>Antihypertensives-<\/strong> Beta 1 Antagonist also called beta blockers\r\n\r\nPrototypes: <\/strong>Metoprolol\r\n\r\nMechanism: <\/strong>Metoprolol primarily blocks Beta-1 receptors in the heart, causing decreased heart rate and decreased blood pressure. However, in higher doses can also block Beta-2 receptors in the lungs, causing bronchoconstriction\r\n

    Therapeutic Effects<\/h3>\r\n