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Chapter 30 Coordinating Care for Patients With Cardiac Disorders
the RAAS compensatory response and reduce afterload. Angiotensin receptor blockers (ARBs) have a similar effect and can be used in patients who are intolerant of ACE inhibitors. Angiotensin receptor–neprilysin inhibitors (ARNIs) are a class of medications that combine an ARB with a neprilysin inhibitor (valsartan with sacubitril) and can be used in place of an ACE inhibitor or ARB. Nepri- lysin is an enzyme that breaks down natriuretic peptides (BNP), which produces natural diuresis and vasodilation. By blocking neprilysin, natriuretic peptides remain active in increasing urine output and dilating blood vessels. Other medications that may be prescribed to reduce afterload include vasodilators such as hydralazine and isosorbidedi- nitrate. Calcium channel blockers, with the exception of amlodipine, should be avoided in HF due to their myocar- dial depressant effect and lack of demonstrated efficacy.
Contractility is the force of the myocardial muscle contrac- tion. A past mainstay of HF management has been digoxin (Lanoxin), an oral positive inotropic medication used to increase cardiac contractility and reduce heart rate. Its use is being questioned. Although patients realize a reduction in symptoms, overall mortality is not decreased. Patients on digoxin (Lanoxin) are prone to toxicities, with symptoms such as nausea and vomiting and visual disturbances (e.g., yellow halos around lights). Care must be taken to monitor patients closely to avoid the later signs of toxicity, such as bradycardia and dysrhythmias. See Table 30.7 for a sum- mary of medications used in the treatment of HF. Medical management of HF often requires multi- ple medications from different classes to achieve optimal results. For instance, patients can be prescribed spironolac- tone, furosemide, and carvedilol to manage their HF along with their other routine medications. In combination, these medications have been shown to improve survival in patients with HF by slowing or stopping the progression of ventricular remodeling and dysfunction. An acute exacerbation of HF is typically treated with IV medications that can more quickly and effectively decrease preload and afterload and increase contractility. Nitroglyc- erin and nitroprusside (Nitropress), potent vasodilators, are commonly used. Intravenous inotropic agents (e.g., dopamine) can be used to increase contractility, whereas inodilators, agents with both positive inotropic and vaso- dilator effects (e.g., dobutamine and milrinone), provide positive inotropic effects and reduce afterload. All these
Safety Alert
Medication Safety Alert: ARNIs Like ACE inhibitors, the neprilysin inhibitor
in an ARNI prevents the breakdown of bradykinin as well as natriuretic peptides. Bradykinin is a cause of angioedema. The combination of an ACE inhibitor and ARNI significantly increases the risk of angioedema. An ARNI should not be given at the same time or within 36 hours of an ACE inhibitor. An ARNI should not be given to patients who had angioedema in the past.
Table 30.7 Medications Used in the Treatment of Heart Failure
Medication Classification
Mechanism of Action
Exemplars
Nursing Implications
Angiotensin-converting enzyme (ACE) inhibitors
Lisinopril (Zestril) Enalapril (Vasotec)
Monitor BP, renal function, and electrolytes.
Block the conversion of angiotensin I to angiotensin II, which is a vasocon- striction. This produces vasodilation. Reduces afterload. Block angiotensin II at receptor sites, which produces vasodilation. Reduces afterload.
Angiotensin receptor blockers/antagonists (ARBs) Angiotensin receptor–neprilysin inhibitor (ARNi)
Losartan (Cozaar) Valsartan (Diovan) Valsartan/sacubitril (Entresto)
Monitor BP, renal function, and electrolytes.
Sacubitril inhibits neprilysin, which causes vasodilation. Reduce afterload. See ARB for valsartan action.
Monitor BP, renal function, and electrolytes.
Arterial vasodilators
Isosorbide dinitrate (Isordil) Nitroprusside (Nipride)
Monitor BP, pulses, level of consciousness. Assess for orthostatic hypotension. Increases fall risk in older adults
Dilate arteries. This reduces BP and makes it easier for the heart to eject blood. Reduces afterload and increases cardiac output.
Hydralazine (Apresoline)
Continued
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