Exam 3 part 2 Ch. 41 & 44; Chapters 45, 46, & 47

Sodium Nitroprusside •Adverse effects

-Excessive hypotension -Cyanide poisoning -Thiocyanate toxicity

Angiotensin II Receptor Blockers (ARBs) •Adverse effects

-Angioedema -Fetal harm -Renal failure -ARBs do not promote accumulation of bradykinin in the lung and therefore have a lower instance of cough

Amiloride •Drug interaction

-ACE inhibitors; other drugs with hyperkalemia

Diltiazem •Therapeutic uses

-Angina pectoris -Hypertension -Cardiac dysrhythmias •Atrial flutter, atrial fibrillation, paroxysmal tachycardia

Nifedipine •Therapeutic uses

-Angina pectoris -Hypertension -Investigational basis: To relieve migraine headache and to suppress preterm labor

Verapamil •Therapeutic uses

-Angina pectoris •Vasospastic angina and angina of effort -Essential hypertension •Second-line agent after thiazide diuretics -Cardiac dysrhythmias •Atrial flutter, atrial fibrillation, paroxysmal supraventricular tachycardia -Migraine

•Anatomy kidney

-Basic functional unit of the kidney: Nephron -Four functionally distinct regions •Glomerulus •Proximal convoluted tubule •Loop of Henle Distal convoluted tubule

Angiotensin II Receptor Blockers (ARBs) •Mechanism of action and overview of pharmacologic effects

-Block access of angiotensin II -Cause dilation of arterioles and veins -Prevent angiotensin II from inducing pathologic changes in cardiac structure -Reduce excretion of potassium -Decrease release of aldosterone -Increase renal excretion of sodium and water -Do not inhibit kinase II Do not increase levels of bradykinin

How diuretics work

-Blockade of sodium and chloride reabsorption

Spironolactone •Mechanism of action

-Blocks aldosterone in the distal nephron -Retention of potassium Increased excretion of sodium

Diltiazem •Actions

-Blocks calcium channels in the heart and blood vessels (similar to verapamil) -Lowers blood pressure •Arteriolar dilation •Direct suppressant/reflex cardiac stimulation = Little net effect on the heart

Amiloride •Mechanism of action

-Blocks sodium-potassium exchange in the distal nephron

•Antihypertensive mechanisms: Sites of drug action

-Brainstem -Sympathetic ganglia -Terminals of adrenergic nerves -Beta1-adrenergic receptors on the heart -Alpha1-adrenergic receptors on blood vessels -Vascular smooth muscle -Renal tubules -Beta1 receptors on juxtaglomerular cells -Angiotensin-converting enzyme (ACE) -Angiotensin II receptors -Aldosterone receptors

Amiloride •Therapeutic use

-Counteract potassium loss caused by more powerful diuretics

Hydrochlorothiazide Drug interactions

-Digoxin -Augments effects of hypertensive medications -Can reduce renal excretion of lithium (leading to accumulation) -NSAIDs may blunt diuretic effect -Can be combined with ototoxic agents without increased risk of hearing loss

Furosemide [Lasix] •Drug interactions

-Digoxin -Ototoxic drugs -Potassium-sparing diuretics -Lithium -Antihypertensive agents -Nonsteroidal antiinflammatory drugs

Verapamil •Drug interactions

-Digoxin -Beta-adrenergic blocking agents

Diltiazem •Drug interactions

-Digoxin Beta-adrenergic blocking agents

Triamterene •Mechanism of action

-Disrupts sodium-potassium exchange in the distal nephron -Direct inhibitor of the exchange mechanism -Decreases sodium reuptake -Inhibits ion transport

Angiotensin-Converting Enzyme (ACE) Inhibitors drug interactions

-Diuretics -Antihypertensive agents -Drugs that raise potassium levels -Lithium -Nonsteroidal antiinflammatory drugs

•Classes of antihypertensive drugs

-Diuretics •Thiazide diuretics •Loop diuretics •Potassium-sparing diuretics -Sympatholytics (antiadrenergic drugs) •Beta-adrenergic blockers •Alpha1 blockers •Alpha/beta blockers: Carvedilol and labetalol •Centrally acting alpha1 agonists •Adrenergic neuron blockers -Direct-acting vasodilators: Hydralazine and minoxidil -Calcium channel blockers -Drugs that suppress RAAS •ACE inhibitors •Angiotensin II receptor blockers •Aldosterone antagonists •Direct renin inhibitors: Type 2 diabetes mellitus precautions

Mannitol •Adverse effects

-Edema -Headache -Nausea -Vomiting -Fluid and electrolyte imbalance

•Principal indications for vasodilators

-Essential hypertension -Hypertensive crisis -Angina pectoris -Heart failure -Myocardial infarction -Pheochromocytoma -Peripheral vascular disease -Pulmonary arterial hypertension -Production of controlled hypotension during surgery

Angiotensin-Converting Enzyme (ACE) Inhibitors •Preparations, dosage, and administration

-Except for enalaprilat, all ACE inhibitors are administered orally -All are available in single-drug formulations -Except for captopril and moexipril, all oral formulations may be administered without regard to meals

Angiotensin-Converting Enzyme (ACE) Inhibitors •Adverse effects

-First-dose hypotension -Fetal injury -Cough -Angioedema •ACE inhibitors can cause angioedema, a potentially life-threatening reaction. If patients report edema of the tongue, lips, or eyes, emergency care should be sought immediately. The patient must never take ACE inhibitors again. -Hyperkalemia -Renal failure -Neutropenia

Nifedipine •Adverse effects

-Flushing -Dizziness -Headache -Peripheral edema -Gingival hyperplasia -Chronic eczematous rash in older patients -Reflex tachycardia -Increases cardiac oxygen demand -Can increase pain in angina patients -Can be combined with a beta blocker for prevention of reflex tachycardia •Note: Beta blockers decrease the adverse cardiac effects of nifedipine but can intensify the adverse cardiac effects of verapamil and diltiazem

•Regulation of blood pressure by the renin-angiotensin-aldosterone system

-Helps regulate blood pressure in the presence of hemorrhage, dehydration, or sodium depletion -Acts in two ways: •Constricts renal blood vessels •Acts on the kidney to promote retention of sodium and water and excretion of potassium •Tissue (local) angiotensin II production

med for •Selective dilation of arterioles

-Hydralazine

Amiloride •Adverse effects

-Hyperkalemia

Spironolactone •Adverse effects

-Hyperkalemia -Benign and malignant tumors -Endocrine effects

Triamterene •Adverse effects

-Hyperkalemia -Leg cramps -Nausea -Vomiting -Dizziness -Blood dyscrasias (rare)

Spironolactone •Therapeutic uses

-Hypertension -Edematous states -Heart failure (decreases mortality in severe failure) -Primary hyperaldosteronism -Premenstrual syndrome -Polycystic ovary syndrome -Acne in young women

Angiotensin-Converting Enzyme (ACE) Inhibitors therapeutic uses

-Hypertension -Heart failure -Myocardial infarction (MI) -Diabetic and nondiabetic nephropathy -Prevention of MI, stroke, and death in patients at high cardiovascular risk

Triamterene •Therapeutic uses

-Hypertension -Edema

Angiotensin II Receptor Blockers (ARBs) •Therapeutic uses

-Hypertension, heart failure, myocardial infarction -Diabetic nephropathy -Patient unable to tolerate ACE inhibitors: Protection against MI, stroke, and death from cardiovascular (CV) causes in high-risk patients -May prevent development of diabetic retinopathy -New data show that ACE inhibitors and angiotensin II receptor blockers (ARBs) are not effective for primary prevention of nephropathy in normotensive diabetic patients

Hydrochlorothiazide •Adverse effects

-Hyponatremia, hypochloremia, and dehydration -Hypokalemia -Use in pregnancy and lactation -Hyperglycemia -Hyperuricemia Impact on lipids, calcium, and magnesium

Furosemide (Lasix) •Adverse effects

-Hyponatremia, hypochloremia, and dehydration -Hypotension •Loss of volume •Relaxation of venous smooth muscle -Hypokalemia -Ototoxicity -Hyperglycemia -Hyperuricemia -Use in pregnancy Impact on lipids, calcium, and magnesium

Diuretics •Adverse effects

-Hypovolemia -Acid-base imbalance Electrolyte imbalances

Immediate release Nifedipine

-Immediate release (not sustained) •Has been associated with increased mortality in patients with MI and unstable angina •Other rapid-acting calcium channel blockers also associated •No cause-and-effect relationship established •National Heart, Lung, and Blood Institute (NHLBI) recommends that these be used with great caution

Nifedipine •Direct effects

-Limited to blockade of Ca channels in vascular smooth muscle (VSM) •No direct suppressant effects on: -Automaticity, AV conduction, or contractile force

Nifedipine •Indirect effects

-Lowered blood pressure (BP) activates baroreceptor reflex -Primarily with immediate release versus sustained release

Hydrochlorothiazide

-Most widely used -Action: Early segment distal convoluted tubule -Peaks in 4-6 hours

med for •Selective dilation of veins

-Nitroglycerin

•Blood pressure (defined by JNC 8)

-Normal •Systolic BP below 130 mm Hg and diastolic BP below 80 mm Hg -Prehypertension •Systolic BP of 120-139 mm Hg or diastolic BP of 80-89 mm Hg -Hypertension •Systolic BP above 140 mm Hg or diastolic BP above 90 mm Hg •Stage 2 hypertension: Systolic BP and diastolic BP in different categories (for example, 160/92 mm Hg)

Hydralazine •Drug interactions

-Other antihypertensive agents -Avoid excessive hypotension -Combined with beta blocker to protect against reflex tachycardia and with diuretics to prevent sodium and water retention and expansion of blood volume

Eplerenone AE and drug interactions

-Pharmacokinetics •Absorption is not affected by food -Adverse effects •Hyperkalemia -Drug interactions •Inhibitors of CYP3A4 •Drugs that raise potassium levels •Use with caution when combined with lithium

•Adverse effects related to vasodilation

-Postural hypotension •Teach patients about symptoms of hypotension (lightheadedness, dizziness) and advise them to sit or lie down if these occur. Avoid abrupt transitions from a supine or seated position to an upright position. -Reflex tachycardia -Expansion of blood volume

med for •Dilation of arterioles and veins

-Prazosin

Mannitol

-Promotes diuresis by creating osmotic force within lumen of the nephron Osmotic Diuretic

Diuretics •Site of action

-Proximal tubule produces greatest diuresis

Angiotensin-Converting Enzyme (ACE) Inhibitors

-Reduce levels of angiotensin II -Increase levels of bradykinin

Hydralazine •Adverse effects

-Reflex tachycardia -Increased blood volume -Systemic lupus erythematosus-like syndrome -Headache, dizziness, weakness, and fatigue

Minoxidil •Adverse effects

-Reflex tachycardia -Sodium and water retention -Hypertrichosis -Pericardial effusion

•Actions of aldosterone

-Regulation of blood volume and blood pressure -Pathologic cardiovascular effects

•Formation of angiotensin II by renin and angiotensin-converting enzyme (ACE)

-Renin •Catalyzes the formation of angiotensin I from angiotensinogen •Regulation of renin release -Angiotensin-converting enzyme (kinase II) •Catalyzes the conversion of angiotensin I (inactive) to angiotensin II (highly active)

Verapamil •Toxicity

-Severe hypotension -Bradycardia and AV block -Ventricular tachydysrhythmias Gastric lavage and activated charcoal

Diltiazem •Adverse effects

-Similar to verapamil, except for less constipation -Dizziness -Flushing -Headache -Edema of ankles and feet -Exacerbates bradycardia, sick sinus syndrome, heart failure, second- or third-degree heart block

Spironolactone •Drug interactions

-Thiazide and loop diuretics -Agents that raise potassium levels

•Actions of angiotensin II

-Vasoconstriction -Release of aldosterone -Alteration of cardiac and vascular structure

Eplerenone MOA & uses?

Aldosterone Antagonist -Mechanism of action •Selective blockade of aldosterone receptors -Therapeutic uses •Hypertension •Heart failure

Spironolactone MOA & uses

Aldosterone Antagonists -Mechanism of action •Blocks aldosterone receptors •Binds with receptors for other steroid hormones -Therapeutic uses •Hypertension Heart failure

objectives

Chapter 41: Diuretics: This chapter introduces diuretics: how they work, their impact on extracellular fluid, and their classification. The chapter also discusses high-ceiling (loop) diuretics, thiazides and related diuretics, potassium-sparing diuretics, and osmotic diuretics. State factors that should be considered when selecting a diuretic, focusing on the efficacy of the various agents, dose-response relationships, and the potential for adverse effects in patients with other disorders. Describe the adverse effects, contraindications, or precautions for the various diuretics. State the expected effects of thiazides and loop diuretics and identify the pre-existing conditions that might require extra caution if use of these diuretics is anticipated. Chapter 44: Drugs Acting on the Renin-Angiotensin-Aldosterone System:This chapter focuses on four families of drugs: angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), direct renin inhibitors (DRIs), and aldosterone antagonists. Very important!!!! If you don't understand this, make sure you do before you finish this module!!!!! Describe the main components of the RAAS/ explain how the overall system is regulated. Describe the effects of ACE inhibitors on blood pressure and on renal regulation of sodium, potassium, and water excretion. Compare and contrast the actions of angiotensin II receptor blockers (antagonists/receptor blockers, such as losartan) with those of an ACE inhibitor or direct renin inhibitors. State the two main contraindications to administration of ACE inhibitors, ARBs, and direct renin inhibitors. Discuss the major adverse effect of aldosterone antagonists (hyperkalemia) and the implications this effect has with regard to combination therapy with ACE inhibitors or ARBs.

Verapamil •Adverse effects

Constipation •Most common complaint •Results from blockade of calcium channels in smooth muscle of the intestine •Especially severe for older adults •Can be decreased by increasing dietary fiber and fluids -Dizziness -Facial flushing -Headache -Edema of ankles and feet -Gingival hyperplasia -Heart block

Chapter 45: Calcium Channel Blockers:This chapter focuses on calcium channel blockers (CCBs), which are drugs that prevent calcium ions from entering cells. Widely used to treat hypertension, angina pectoris, and cardiac dysrhythmias, CCBs' greatest effects are exerted on the heart and blood vessels.

Describe the functional linkage between beta-adrenergic receptors and calcium channels in the heart. Briefly describe the calcium channel and the relationships between intracellular and extracellular calcium concentrations as they affect smooth and cardiac muscle contractile function. Compare and contrast the sites of action of nifedipine with those of diltiazem or verapamil. Also, explain how the differences between the dihydropyridines and verapamil or diltiazem affect their clinical use and name the most common side effects. Identify other drugs, noted and described in the cardiovascular module that should not be administered with CCBs because of the risk of excessive depression of cardiac contractility, rate, and electrical activity. Also, specify whether these precautions apply to dihydropyridine-type CCBs, just to verapamil or diltiazem, or to all CCBs, and explain why.

Aldosterone Antagonists

Eplerenone Spironolactone

Verapamil and Diltiazem: Hemodynamic Effects

Five direct hemodynamic effects -Blockade at peripheral arterioles •Reduces arterial pressure -Blockade at arteries and arterioles of heart •Increases coronary perfusion -Blockade at SA node •Reduces heart rate -Blockade at AV node (most important) •Decreases AV nodal conduction -Blockade in the myocardium Decreases force of contraction Indirect (reflex) hemodynamic effects -Baroreceptor reflex Net effects -Little or no net effect on cardiac performance -Vasodilation accompanied by reduced arterial pressure and increased coronary perfusion

Chapter 46: Vasodilators:This chapter begins by considering concepts that apply to vasodilators as a group and then discusses the pharmacology of individual agents.

Identify the main pharmacologic causes of vasodilation. Explain how reducing afterload and preload can help a patient with hypertension or heart failure. Describe how excessive vasodilation can cause adverse effects that can actually worsen many of the conditions for which vasodilators are given. State the expected compensatory cardiac and renal responses that occur when a drug that does nothing but dilate arterioles is given and identify adjunctive drugs that might be used to control those responses. Know the adverse affects of vasodilators.

Furosemide (Lasix) -Therapeutic uses

Pulmonary edema Edematous states Hypertension

Chapter 47: Drugs for Hypertension:This chapter discusses the classification of blood pressure, types of HTN, consequences of HTN, basic considerations for management of chronic HTN, lifestyle modifications, drug therapy, drugs for hypertensive emergencies, and drugs for hypertensive disorders of pregnancy.

Start with this chapter. If you understand this info, you will not need to spend much time on the info in Chapters 44, 45, 46. Figure 47-2 is very important Also need to know the JNC8 guidelines. Useful for drug selection. State the major factors that influence the choice of antihypertensive drug (or drug combination) for a patient with a stated severity of essential hypertension. State how specified comorbidity (e.g., heart failure, diabetes, asthma) would influence the drug choice for or against a particular drug class. Explain the blood pressure control gains to be expected by progressively increasing the dosage of one antihypertensive drug rather than adding drugs in other classes to the initial agent. Discuss the drugs for hypertensive emergency.

Dihydropyridines

•Agents that act mainly on vascular smooth muscle -Nifedipine [Adalat, Nifedical, Nifediac, Procardia] •Significant blockade of calcium channels in blood vessels •Minimal blockade of calcium channels in the heart •Similar to verapamil in some respects and quite different in others

Verapamil and Diltiazem

•Agents that act on vascular smooth muscle and the heart •Hemodynamic effects -Direct effects on the heart and blood vessels -Indirect (reflex) effects -Net effects

Direct Renin Inhibitors

•Aliskiren -Binds tightly with renin and inhibits the cleavage of angiotensinogen to angiotensin I -Side effects •Angioedema, cough, GI effects, hyperkalemia, fetal injury, and death

Are there any other steps the nurse should take regarding IV administration of mannitol

•Along with following all the appropriate safety precautions for medication administration, the nurse should use a filter needle to withdraw mannitol from the vial, as well as an in-line filter for IV infusion, to prevent crystals from entering the circulation.

Thiazides and Related Diuretics

•Also known as benzothiadiazides •Effects similar to those of loop diuretics -Increase renal excretion of sodium, chloride, potassium, and water -Elevate levels of uric acid and glucose •Maximum diuresis is considerably lower than with loop diuretics •Not effective when urine flow is scant (unlike with loop diuretics)

The nurse teaches a patient about benazepril [Lotensin]. Which statement by the patient requires an intervention by the nurse? A."I use NoSalt instead of salt to season foods." B."I eat sweet potatoes once or twice a week." C."I drink 4 ounces of prune juice each morning." "I like asparagus because it's high in vitamin K."

•Answer: A •Rationale: An adverse effect of angiotensin-converting enzyme (ACE) inhibitors (for example, benazepril) is hyperkalemia. Significant potassium accumulation is usually limited to patients taking potassium supplements, salt substitutes (which contain potassium), or a potassium-sparing diuretic. Patients should be instructed to avoid potassium supplements and potassium-containing salt substitutes unless they are prescribed. Sweet potatoes and prune juice are foods high in potassium; asparagus is high in vitamin K. Foods high in vitamin K are restricted for patients who are prescribed warfarin [Coumadin].

The health care provider prescribes sustained-release verapamil [Calan SR] to an 82-year-old patient who takes digoxin [Lanoxin] daily. Which action is most appropriate for the nurse to take? A.Monitor the patient's cardiac rhythm continuously. B.Assess the patient for tachycardia and hypertension. C.Maintain the patient on bed rest for 8 to 10 hours. Reduce dietary fiber to prevent loose, watery diarrhea.

•Answer: A •Rationale: Digoxin and verapamil suppress impulse conduction through the atrioventricular (AV) node. When these drugs are used concurrently, the risk of AV block is increased. The cardiac rhythm of patients receiving both medications should be monitored closely. The patient should be monitored for bradycardia and hypotension. Bed rest is not indicated. Constipation may occur; increased dietary fiber and fluids are indicated to prevent constipation.

When providing discharge teaching for a patient who has been prescribed furosemide [Lasix], it is most important for the nurse to include which dietary items to prevent adverse effects of furosemide [Lasix] therapy? A.Oranges, spinach, and potatoes B.Baked fish, chicken, and cauliflower C.Tomato juice, skim milk, and cottage cheese D.Oatmeal, cabbage, and bran flakes

•Answer: A •Rationale: Furosemide may have the adverse effect of hypokalemia. Hypokalemia can be reduced by consuming foods that are high in potassium, such as nuts, dried fruits, spinach, citrus fruits, potatoes, and bananas.

A patient with stage 2 hypertension has been prescribed a thiazide diuretic and an angiotensin-converting enzyme inhibitor. It is most appropriate for the nurse to do what? ● A.Contact the health care provider. B.Administer both drugs to the patient. C.Administer the thiazide diuretic at bedtime. Hold the medications if the blood pressure is normal

•Answer: B •Rationale: A combination of drugs is used to treat stage 2 hypertension; each drug has a different mechanism of action. The nurse should administer antihypertensive medications even if the blood pressure is normal. Thiazide diuretics should be given in the morning because of diuresis.

A patient with heart failure who takes furosemide [Lasix] is diagnosed with bacterial pneumonia. Which medication, if ordered by the physician, should the nurse question? A.Ciprofloxacin [Cipro] B.Gentamicin [Garamycin] C.Amoxicillin [Amoxcil] D.Erythromycin [E-Mycin]

•Answer: B •Rationale: High-ceiling loop diuretics may cause hearing impairment; furosemide may result in deafness that is transient. Because of the risk of hearing loss, caution is needed when high-ceiling diuretics are used in combination with other ototoxic drugs (for example, aminoglycoside antibiotics). Gentamicin is an aminoglycoside. The other antibiotics are safe to administer with furosemide.

A patient is prescribed hydralazine. What is most important for the nurse to teach the patient? A.Precautions for postural hypotension B.Prevention of reflex tachycardia C.High initial dose for slow acetylators D.Recognition of hypertrichosis

•Answer: B •Rationale: Hydralazine is usually combined with a beta blocker to protect against reflex tachycardia. Hydralazine is an arterial vasodilator; postural hypotension is minimal. Hydralazine is inactivated by acetylation, and the ability to acetylate drugs is genetically determined. To avoid hydralazine accumulation, the dosage should be reduced in slow acetylators. Minoxidil commonly causes hypertrichosis, or increased hair growth.

A patient who is hospitalized for an infection takes eplerenone [Inspra] for heart failure. Which medication, if ordered by the physician, should the nurse question? A.Ciprofloxacin [Cipro] B.Itraconazole [Sporanox] C.Tetracycline [Sumycin] Ampicillin [Principen]

•Answer: B •Rationale: Inhibitors of CYP3A4 can increase levels of eplerenone, thereby posing a risk of toxicity. Weak inhibitors (for example, erythromycin, saquinavir, verapamil, fluconazole) can double eplerenone levels. Strong inhibitors (for example, ketoconazole, itraconazole) can increase levels fivefold. If eplerenone is combined with a weak inhibitor, the eplerenone dosage should be reduced. Eplerenone should not be combined with a strong inhibitor.

A patient with severe hypertension is prescribed minoxidil. Which medications will the nurse expect to be administered to reduce adverse responses to minoxidil? A.Adenosine [Adenocard] and ticlopidine [Ticlid] B.Furosemide [Lasix] and propranolol [Inderal] C.Digoxin [Lanoxin] and captopril [Capoten] D.Donepezil [Aricept] and clonidine [Catapres]

•Answer: B •Rationale: Minoxidil may cause adverse responses (for example, reflex tachycardia, expansion of blood volume, pericardial effusion). Minoxidil should be used with a beta blocker (for example, propranolol) plus intensive diuretic therapy (for example, furosemide).

The nurse instructs a patient about taking nifedipine [Procardia XL]. Which statement made by the patient indicates an understanding of medication teaching? A."I'll stop taking my beta blocker." B."The pill should be swallowed whole." C."The drug will cause constipation." D."This drug treats heart rhythm problems."

•Answer: B •Rationale: Patients should swallow sustained-release tablets whole, without crushing or chewing. Nifedipine may cause reflex tachycardia; beta blockers are prescribed to prevent reflex tachycardia. Nifedipine causes very little constipation. Nifedipine cannot be used to treat dysrhythmias.

A patient diagnosed with heart failure has stage 1 hypertension. Which medication, if ordered by the health care provider, should the nurse question? A.Angiotensin-converting enzyme inhibitor B.Calcium channel blocker C.Thiazide diuretic D.Beta blocker

•Answer: B •Rationale: The patient with heart failure should not receive a calcium channel blocker (for example, verapamil, diltiazem); calcium channel blockers may act on the heart to decrease myocardial contractility, thereby further reducing cardiac output.

Other High-Ceiling (Loop) Diuretics

•Ethacrynic acid [Edecrin] •Bumetanide [Bumex] •Torsemide [Demadex] •All can cause: -Ototoxicity, hypovolemia, hypotension, hypokalemia, hyperuricemia, hyperglycemia, and disruption of lipid metabolism

A patient is prescribed spironolactone [Aldactone] for treatment of hypertension. Which foods should the nurse teach the patient to avoid? A.Baked fish B.Low-fat milk C.Salt substitutes Green beans

•Answer: C •Rationale: Spironolactone is a potassium-sparing diuretic. Medications that are potassium sparing, potassium supplements, and salt substitutes should be avoided. High-potassium foods should also be avoided.

A patient is prescribed verapamil [Calan]. The nurse should assess the patient for which common adverse effects? A.Atrial fibrillation, photosensitivity, and blurred vision B.Tachycardia, stomatitis, and inflammation of the joints C.Constipation, headache, and edema of the ankles and feet Dry mouth, lymphadenopathy, and decreased appetite

•Answer: C •Rationale: The adverse effects of verapamil occur secondary to vasodilation. Common adverse effects include constipation, dizziness, facial flushing, headache, and edema of the ankles and feet.

A patient has hypertension, type 2 diabetes, and chronic kidney disease. Which blood pressure goal would be most beneficial for this patient? A.Blood pressure less than 140/90 mm Hg B.Diastolic blood pressure less than 100 mm Hg C.Blood pressure less than 130/80 mm Hg Systolic blood pressure less than 160 mm Hg

•Answer: C •Rationale: The treatment goal for a person with hypertension and diabetes or chronic kidney disease is less than 130/80 mm Hg.

A patient who is taking spironolactone [Aldactone] is prescribed losartan [Cozaar]. The nurse should take which action? A.Assess for symptoms of hyperkalemia. B.Observe for a hypertensive crisis. C.Administer the medications as scheduled. D.Evaluate for first-dose hypotension.

•Answer: C •Rationale: These medications may be administered together without serious drug interactions. Spironolactone is a potassium-sparing diuretic, and losartan is an angiotensin II receptor blocker (ARB). The hypotensive effects of ARBs are additive with those of other antihypertensive drugs. When an ARB is added to an antihypertensive regimen, dosages of the other drugs may require reduction. The patient would be observed for hypotension (not first-dose hypotension).

A patient is to receive a scheduled dose of diltiazem [Cardizem]. The nurse should hold the medication and contact the prescriber if which of the following is noted? A.The patient's blood pressure is 112/64 mm Hg. B.The patient's cardiac rhythm is atrial fibrillation. C.The patient is complaining of chest pain. D.The patient is in second-degree heart block.

•Answer: D •Rationale: Diltiazem is contraindicated in patients with second-degree or third-degree heart block; diltiazem can exacerbate cardiac dysfunction.

Which patient would most likely be prescribed sodium nitroprusside [Nitropress]? A.A patient with a recent diagnosis of essential hypertension B.A patient with heart failure who receives weekly home visits C.A patient who is hypotensive after a myocardial infarction A patient with a hypertensive crisis in the intensive care unit

•Answer: D •Rationale: Sodium nitroprusside is used to treat hypertensive emergencies. The medication is administered intravenously, with continuous monitoring of blood pressure.

Sodium Nitroprusside actions and use

•Fastest-acting antihypertensive agent •Causes venous and arteriolar dilation •Administration: IV infusion •Onset: Immediate (BP returns to pretreatment level in minutes when stopped) •Used for hypertensive emergencies

Which patient is the most appropriate candidate for both lifestyle changes and drug therapy with an antihypertensive medication? A.A 47-year-old patient with blood pressure of 110/78 mm Hg and with type 2 diabetes mellitus B.A 76-year-old patient with blood pressure of 128/88 mm Hg and a history of dyslipidemia C.A 52-year-old patient with blood pressure of 136/89 mm Hg who smokes 1 pack of cigarettes per day D.A 32-year-old patient with blood pressure of 142/94 mm Hg who is sedentary

•Answer: D •Rationale: Stages 1 and 2 hypertension should be treated with both lifestyle changes and drug therapy to control blood pressure.

The nurse cares for a patient who is prescribed oral bumetanide twice daily. It is most important for the nurse to take which action? A.Monitor the patient for signs and symptoms of hyperkalemia. B.Insert a urinary catheter and assess the hourly urine output. C.Weigh the patient before administering each dose. Schedule the medication to be given at 0800 and 1400

•Answer: D •Rationale: The nurse should administer oral bumetanide with twice-a-day dosing at 0800 and 1400 to minimize nocturia. Daily weights should be obtained in the morning before eating. Patients receiving IV bumetanide are more likely to need hourly monitoring of urine output with a urinary catheter. Bumetanide may cause hypokalemia; signs and symptoms of hypokalemia include irregular heartbeat, muscle weakness, cramping, flaccid paralysis, leg discomfort, extreme thirst, and confusion.

-Principal determinants of blood pressure

•Arterial pressure = Cardiac output × Peripheral resistance •Cardiac output -Heart rate -Myocardial contractility -Blood volume -Venous return -Systems that help regulate blood pressure •Sympathetic baroreceptor reflex •Renin-angiotensin-aldosterone system •Renal regulation of blood pressure

Vasodilation

•Can be produced with a variety of drugs •Some act primarily on veins or arterioles; others act on both types of vessels •Wide variety of therapeutic applications

Drugs for Hypertensive Disorders of Pregnancy

•Chronic hypertension and pregnancy -ACE inhibitors, ARBs, and DRIs are contraindicated during pregnancy -Most other antihypertensives can be continued during pregnancy •Preeclampsia and eclampsia -Hydralazine -Magnesium sulfate (anticonvulsant)

Classification and Sites of Action for calcium channel blockers

•Classification -Dihydropyridines: Nifedipine -Phenylalanine: Verapamil -Benzothiazepine: Diltiazem •Sites of action -Dihydropyridines act primarily on arterioles -Verapamil and diltiazem act on arterioles and on the heart

-Three basic functions of diuretics

•Cleansing of extracellular fluid (ECF) and maintenance of ECF volume and composition •Maintenance of acid-base balance Excretion of metabolic wastes and foreign substances

Mannitol -Pharmacokinetics

•Drug must be given parenterally

Hemodynamic Effects of vasodilation

•Drugs that dilate resistance vessels (arterioles) cause a decrease in cardiac afterload •Drugs that dilate capacitance vessels (veins) reduce the force with which blood is returned to the heart, thus reducing preload

Calcium Channel Blockers

•Drugs that prevent calcium ions from entering cells •Greatest impact on heart and blood vessels •Used to treat hypertension, angina pectoris, and cardiac dysrhythmias •Controversy: Safety for patients with hypertension and diabetes •Also known as calcium antagonists and slow channel blockers

•Promoting adherence

•Educate the patient •Teach self-monitoring •Minimize side effects •Establish a collaborative relationship •Simplify the regimen

Hydrochlorothiazide -Therapeutic uses

•Essential hypertension •Edema Diabetes insipidus

-Three basic renal processes

•Filtration: Occurs at the glomerulus •Reabsorption -99% of water, electrolytes, and nutrients undergo reabsorption •Active tubular secretion -Proximal convoluted tubule

Loop Diuretics

•Furosemide (Lasix): Most frequently prescribed loop diuretic -Mechanism of action •Acts on ascending loop of Henle to block reabsorption

Consequences of Hypertension

•Heart disease -Myocardial infarction (MI) -Heart failure -Angina pectoris •Kidney disease Stroke

Spironolactone -Adverse effects

•Hyperkalemia •Gynecomastia •Menstrual irregularities •Impotence •Hirsutism •Deepening of the voice

Verapamil IV?

•IV verapamil for dysrhythmias can cause severe cardiovascular effects -Blood pressure and ECG should be monitored -Resuscitation equipment should be kept immediately available

-Secondary hypertension

•Identifiable primary cause •Possible to treat the cause directly •Some individuals can actually be cured

•Classification of diuretics -Four major categories

•Loop: Furosemide •Thiazide: Hydrochlorothiazide •Osmotic: Mannitol •Potassium-sparing: Two subcategories -Aldosterone antagonists (spironolactone) -Nonaldosterone antagonists (triamterene) -Fifth group Carbonic anhydrase inhibitors

Mannitol IV has been ordered for the patient. When the IV solution of mannitol arrives from the pharmacy, the nurse notes crystals in the fluid. What is the most appropriate action by the nurse?

•Mannitol may crystallize out of solution if exposed to a low temperature. Accordingly, preparations should be observed for crystals before use. Preparations that contain crystals should be warmed (to redissolve the mannitol) and then cooled to body temperature for administration.

-Primary (essential) hypertension

•No identifiable cause •Chronic, progressive disorder •Population: Older adults, African Americans, postmenopausal women •Treated but not cured (lifelong condition) •Referred to as essential hypertension

Mannitol -Therapeutic uses

•Prophylaxis of renal failure •Reduction of intracranial pressure Reduction of intraocular pressure

-Processes of reabsorption that occur at specific sites along the nephron

•Proximal convoluted tubule •Loop of Henle •Distal convoluted tubule (early segment) •Late distal convoluted tubule and collecting duct (distal nephron) -Sodium-potassium exchange Regulation of urine concentration

Furosemide (Lasix) -Pharmacokinetics

•Rapid onset (PO 60 min; IV 5 min)

Hydralazine actions and use

•Selective dilation of arterioles •Mechanism unknown •Postural hypotension minimal •Therapeutic uses -Essential hypertension -Hypertensive crisis -Heart failure

Minoxidil

•Selective dilation of arterioles •More intense dilation than hydralazine, but causes more severe adverse reactions •Used for severe hypertension unresponsive to safer drugs

Dihydropyridines- others besides nifedipine

•Seven other dihydropyridines available •All similar to nifedipine •Produce greater blockade of Ca channels in the VSM than in the heart -Nicardipine, amlodipine, isradipine, felodipine, nimodipine, nisoldipine, and clevidipine

Drugs for Hypertensive Emergencies

•Sodium nitroprusside •Fenoldopam •Labetalol •Diazoxide •Clevidipine

Lifestyle Modifications for HTN

•Sodium restriction •DASH (Dietary Approaches to Stop Hypertension) eating plan •Alcohol restriction •Aerobic exercise •Smoking cessation •Maintenance of potassium and calcium intake

A patient who sustained a head injury is admitted to the critical care unit with increased intracranial pressure (ICP). The healthcare provider says that a diuretic will be used to lower the patient's ICP. The nurse anticipates that which diuretic will be ordered, and why?

•The nurse anticipates that mannitol, an osmotic diuretic, will be ordered. Intracranial pressure (ICP) that has been elevated by cerebral edema can be reduced with mannitol. The drug lowers ICP because its presence in the blood vessels of the brain creates an osmotic force that draws edematous fluid from the brain into the blood. There is no risk of increasing cerebral edema because mannitol cannot exit the capillary beds of the brain.

Potassium-Sparing Diuretics

•Useful responses -Modest increase in urine production -Substantial decrease in potassium excretion •Rarely used alone for therapy •Aldosterone antagonist -Spironolactone •Nonaldosterone antagonists -Triamterene -Amiloride

Physiologic Functions and Consequences of calcium Blockade

•Vascular smooth muscle -Calcium channels open = Contractile process -Calcium channels blocked = Vasoconstriction •Therapeutic doses -Selectively act on peripheral arterioles and arteries and arterioles of the heart -No significant effect on veins

Nifedipine

•Vasodilation by blocking calcium channels •Blocks in vascular smooth muscle •Very little blockade of heart calcium (Ca) channels •Cannot be used to treat dysrhythmias •Less likely than verapamil to exacerbate preexisting cardiac disorders

Nifedipine -Net effect

•Vasodilation by blocking calcium channels •Lowered blood pressure •Increased heart rate Increased contractile force