Drugs Affecting Blood Pressure PDF

Chapter 43: Drugs Affecting Blood Pressure Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Elements Determining Blood Pressure  Heart Rate  Stroke Volume o Amount of blood pumped out of the ventricle with each heartbeat  Total Peripheral Resistance o Resi...

Chapter 43: Drugs Affecting Blood Pressure Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Elements Determining Blood Pressure  Heart Rate  Stroke Volume o Amount of blood pumped out of the ventricle with each heartbeat  Total Peripheral Resistance o Resistance of the muscular arteries to the blood being pumped through Copyright © 2017 Wolters Kluwer All Rights Reserved Control of Blood Pressure Copyright © 2017 Wolters Kluwer All Rights Reserved The Renin–Angiotensin System Copyright © 2017 Wolters Kluwer All Rights Reserved Risks for Coronary Artery Disease Related to Hypertension Thickening of the heart muscle Increased pressure generated by the muscle on contraction Increased workload on the heart Copyright © 2017 Wolters Kluwer All Rights Reserved Conditions Related to Untreated Hypertension  CAD and Cardiac Death  Stroke  Renal Failure  Loss of Vision Copyright © 2017 Wolters Kluwer All Rights Reserved Categories Rating the Severity of Hypertension Copyright © 2017 Wolters Kluwer All Rights Reserved Stepped Care Approach to Treating Hypertension  Step 1: Lifestyle modifications are instituted  Step 2: If the measures in step 1 are not sufficient, drug therapy is added  Step 3: If the patient’s response is inadequate, drug dose or class may be changed or another drug added  Step 4: Includes all of the above measures with the addition of more antihypertensive agents until blood pressure is controlled Copyright © 2017 Wolters Kluwer All Rights Reserved Use Of Drugs Affecting Blood Pressure Across The Lifespan Copyright © 2017 Wolters Kluwer All Rights Reserved Types of Drugs Used to Control Blood Pressure  Diuretic: Decreases serum sodium levels and blood volume ( See chapter 51 diuretics)  ACE Inhibitor: Blocks the conversion of angiotensin I to angiotensin II; an angiotensin II receptor blocker; blocking effects of angiotensin on blood vessels  Beta-Blocker: Leads to a decrease in heart rate and strength of contraction as well as vasodilatation  Calcium Channel Blocker: Relaxes muscle contraction or other autonomic blockers  Vasodilators- Acts directly on vascular smooth muscle to cause muscle relaxation, leading to vasodilatation, and drop in blood pressure Copyright © 2017 Wolters Kluwer All Rights Reserved ACE Inhibitor #1  Treatment of Hypertension o Benazepril (Lotensin), Captopril (Capoten), Enalapril (Vasotec) Enalaprilat (generic) o Fosinopril (generic), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik) Copyright © 2017 Wolters Kluwer All Rights Reserved ACE Inhibitor #2  Actions o Blocks ACE from converting angiotensin I to angiotensin II, leading to a decrease in blood pressure, a decrease in aldosterone production, and a small increase in serum potassium levels along with sodium and fluid loss  Indications o Treatment of hypertension, congestive heart failure (CHF), diabetic nephropathy, left ventricular dysfunction following an MI  Pharmacokinetics o Well absorbed, widely distributed, metabolized in the liver, and excreted in the urine and feces Copyright © 2017 Wolters Kluwer All Rights Reserved ACE Inhibitor #3  Contraindications o Allergies o Impaired renal function o Pregnancy and lactation  Caution o CHF Copyright © 2017 Wolters Kluwer All Rights Reserved ACE Inhibitor #4  Adverse Effects o Related to the effects of vasodilatation and alterations in blood flow o GI irritation o Renal insufficiency o Cough  Drug-to-Drug Interactions o Allopurinol Copyright © 2017 Wolters Kluwer All Rights Reserved Nursing Considerations for ACE Inhibitors  Assess: o History and Physical Exam o Known allergy o Impaired kidney function, pregnancy and lactation o Salt/volume depletion and heart failure o Baseline status before beginning therapy, including o VS, LS, BS, weight, skin, ECG, CBC with differential and electrolytes Copyright © 2017 Wolters Kluwer All Rights Reserved Prototype ACE Inhibitors Copyright © 2017 Wolters Kluwer All Rights Reserved Question #1 Please answer the following questions as true or false. The use of a loop diuretic is the first drug used in the Step Care Management program to treat hypertension. Copyright © 2017 Wolters Kluwer All Rights Reserved Answer to Question #1 False Rationale: A somewhat controversial study, the ALLHAT study, reported in 2002 that patients taking the less expensive, less toxic diuretics did better and had better blood pressure control than patients using other antihypertensive agents. Replications of this study have supported its findings and the use of a thiazide diuretic is currently considered the first drug used in the Step Care Management of Hypertension. Copyright © 2017 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #1  Treatment of hypertension o Azilsartan (Edarbi) o Candesartan (Atacand) o Eprosartan (Teveten) o Irbesartan (Avapro) o Losartan (Cozaar) o Olmesartan (Benicar), telmisartan (Micardis), and valsartan (Diovan) Copyright © 2017 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #2  Action- Selectively bind with the angiotensin II receptors in vascular smooth muscle and in the adrenal cortex to block vasoconstriction and the release of aldosterone  Pharmacokinetics- well absorbed and undergo metabolism in the liver by the cytochrome P450 system. They are excreted in the feces and urine Copyright © 2017 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #3  Contraindications o Allergy, pregnancy, and lactation  Caution o Hepatic or renal dysfunction, and hypovolemia  Adverse Effects o Headache, dizziness, syncope, weakness o GI complaints o Skin rash or dry skin  Drug-to-Drug Interactions o Phenobarbital Copyright © 2017 Wolters Kluwer All Rights Reserved Nursing Considerations for Angiotensin II Receptor Blockers  Assess: o History and Physical Exam o Known allergy o Impaired renal and hepatic function, pregnancy and lactation o Hypovolemia, assess baseline status before beginning therapy including, skin, VS, LS, baseline ECG and renal and function tests Copyright © 2017 Wolters Kluwer All Rights Reserved Prototype Angiotensin II Receptor Blockers Copyright © 2017 Wolters Kluwer All Rights Reserved Renin Inhibitor  New class of drugs for treating hypertension which directly inhibits renin, leading to decreased plasma renin activity and inhibiting the conversion of angiotensinogen to angiotensin I o aliskiren (Tekturna)  Pharmacokinetics- slowly absorbed from the GI tract, with peak levels in 3 hours. It is metabolized in the liver, with a half-life of 24 hours, and is excreted in the urine  Contraindications- Pregnancy and lactation  Adverse effects- Risk of hyperkalemia  Drug-to- Interactions- Furosemide and ACE Inhibitors Copyright © 2017 Wolters Kluwer All Rights Reserved Calcium Channel Blockers #1  Decrease BP, cardiac work load, and myocardial oxygen consumption o Amlodipine (Norvasc), felodipine (Plendil), o isradipine(generic), nicardipine (Cardene) o Diltiazem (Cardizem CD), nifedipine (Procardia XL), nisoldipine (Sular), and verapamil (Calan SR) Copyright © 2017 Wolters Kluwer All Rights Reserved Calcium Channel Blockers #2  Actions o Inhibits the movement of calcium ions across the membranes of cardiac and arterial muscle cells, depressing the impulse and leading to slowed conduction, decreased myocardial contractility, and dilation of arterioles, which lowers blood pressure and decreases myocardial oxygen consumption  Indications o Treatment of essential hypertension in the extended release form  Pharmacokinetics o Well absorbed, metabolized in the liver, and excreted in the urine Copyright © 2017 Wolters Kluwer All Rights Reserved Calcium Channel Blockers #3  Contraindications o Allergy, heart block or sick sinus syndrome, renal or hepatic dysfunction, pregnancy, and lactation  Adverse Effects o Related to effects on cardiac output o GI symptoms o Cardiovascular symptoms  Drug-to-Drug Interactions o Cyclosporine Copyright © 2017 Wolters Kluwer All Rights Reserved Nursing Considerations for Calcium Channel Blocker  Assess: o History and Physical Exam o Known allergy o The main use of calcium-channel blockers is for the treatment of angina. See Chapter 46 for the nursing considerations of calcium channel blockers Copyright © 2017 Wolters Kluwer All Rights Reserved Prototype Calcium Channel Blockers Copyright © 2017 Wolters Kluwer All Rights Reserved Question #2 The mechanism of action of an ACE inhibitor is the blocking of ACE from converting angiotensin I to angiotensin II. What does this cause? A. Decrease in serum potassium levels B. Decrease in aldosterone production C. Sodium and fluid loss D. Increase in blood pressure Copyright © 2017 Wolters Kluwer All Rights Reserved Answer to Question #2 B. Decrease in aldosterone production Rationale: Blocks ACE from converting angiotensin I to angiotensin II, leading to a decrease in blood pressure, a decrease in aldosterone production, and a small increase in serum potassium levels along with sodium and fluid loss Copyright © 2017 Wolters Kluwer All Rights Reserved Vasodilators #1  Most of the vasodilators are reserved for use in severe hypertension, malignant hypertension, or hypertensive emergencies o Diazoxide (Hyperstat): IV for hospitalized patients with severe hypertension; increases blood glucose levels o Hydralazine (Apresoline): Maintains increased renal blood flow o Minoxidil (Loniten): Used only for severe and unresponsive hypertension o Nitroprusside (Nitropress): Used for hypertensive crisis; maintain hypertension during surgery Copyright © 2017 Wolters Kluwer All Rights Reserved Vasodilators #2  Actions o Acts directly on vascular smooth muscle to cause muscle relaxation, leading to vasodilatation, and drop in blood pressure  Indications o Severe hypertension  Pharmacokinetics o Rapidly absorbed and widely distributed, metabolized in the liver, and primarily excreted in the urine  Contraindications o Allergy, pregnancy, lactation, cerebral insufficiency Copyright © 2017 Wolters Kluwer All Rights Reserved Vasodilators #3  Caution o Peripheral vascular disease, CAD, CHF, or tachycardia  Adverse Effects o Related to changes in the blood pressure o GI upset o Cyanide Toxicity  Drug-to-Drug Interactions o Based on individual drug Copyright © 2017 Wolters Kluwer All Rights Reserved Nursing Considerations for Vasodilators  Assess: o History and Physical Exam o Known allergy o Impaired kidney or liver function, pregnancy or lactation o Baseline status to include, VS, LS, BS, skin, ECG, and appropriate lab values Copyright © 2017 Wolters Kluwer All Rights Reserved Prototype Vasodilators Copyright © 2017 Wolters Kluwer All Rights Reserved Diuretics  Increase the excretion of sodium and water from the kidney to lower blood pressure (Figure 43.3). See Chapter 51 for a detailed discussion of these agents. o Thiazide and thiazide-like diuretics: chlorothiazide (Diuril), hydrochlorothiazide (HydroDIURIL), methyclothiazide (generic), chlorthalidone (generic), indapamide (generic), and metolazone (Zaroxolyn) o Potassium-sparing diuretics: amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium) Copyright © 2017 Wolters Kluwer All Rights Reserved Antihypotensive Agents Sympathetic Adrenergic Agonists or Vasopressors #1  If BP becomes too low (hypotension) the vital centers in the brain and the rest of the tissues of the body may not receive sufficient oxygenated blood to continue functioning o Dobutamine (generic), dopamine (generic), ephedrine (generic), epinephrine (Adrenalin, AdrenaClick), isoproterenol (Isuprel), orepinephrine (Levophed), and phenylephrine (generic). Copyright © 2017 Wolters Kluwer All Rights Reserved  Antihypotensive Agents Sympathetic Adrenergic Agonists or Vasopressors #2  Actions- Activates alpha-receptors in arteries and veins to produce an increase in vascular tone and an increase in blood pressure  Indications- Symptomatic treatment of orthostatic hypotension  Pharmacokinetics- Absorbed from GI tract, metabolized in the liver, and excreted in the urine  Contraindications- Supine hypertension, CAD, pheochromocytoma, and with urinary retention Copyright © 2017 Wolters Kluwer All Rights Reserved Antihypotensive Agents Sympathetic Adrenergic Agonists or Vasopressors #3  Caution o Pregnancy and lactation o Visual problems  Adverse Effects o Related to stimulation of alpha-receptors  Drug-to-Drug Interactions o Cardiac glycosides, beta blockers, alpha-adrenergic agents, and corticosteroids Copyright © 2017 Wolters Kluwer All Rights Reserved Nursing Considerations for Antihypotensive Agents Sympathetic Adrenergic Agonists or Vasopressors  Assess: o History and Physical Exam o Known allergy o Impaired kidney or liver function, pregnancy and lactation o CV dysfunction; visual problems; urinary retention; and pheochromocytoma o Baseline to include, VS, skin, weight, respirations and LS, appropriate lab values Copyright © 2017 Wolters Kluwer All Rights Reserved Question #3 The nurse is caring for a 27-year-old African American woman who was just prescribed an ACE inhibitor for management of her hypertension. What should be advised related to contraception? A. The use of spermicidal jellies is recommended. B. The mini pill is the contraception method of choice. C. Use barrier contraceptives to prevent pregnancy while taking these drugs. D. No special precautions need to be taken. Copyright © 2017 Wolters Kluwer All Rights Reserved Answer to Question #3 C. Use barrier contraceptives to prevent pregnancy while taking these drugs. Rationale: The safety for the use of these drugs during pregnancy has not been established. ACE inhibitors, ARBs, and renin inhibitors should not be used during pregnancy, and women of child-bearing age should be advised to use barrier contraceptives to prevent pregnancy while taking these drugs. Copyright © 2017 Wolters Kluwer All Rights Reserved