Drugs Affecting Blood Pressure PDF

Chapter 43 Drugs Affecting Blood Pressure Copyright Copyright © 2012 © 2017 Wolters Wolters Kluwer Kluwer All Health |...

Chapter 43 Drugs Affecting Blood Pressure Copyright Copyright © 2012 © 2017 Wolters Wolters Kluwer Kluwer All Health | Lippincott Rights Reserved Williams & Wilkins Blood Pressure Control Mean arterial pressure determined by o Heart rate o Stroke volume: amount of blood pumped out of the ventricle with each heartbeat o Total peripheral resistance: resistance of the muscular arteries to the blood being pumped through Autonomic nervous system Baroreceptors Renin–angiotensin–aldosterone system Copyright © 2023 Wolters Kluwer All Rights Reserved Control of Blood Pressure Copyright © 2023 Wolters Kluwer All Rights Reserved The Renin–Angiotensin–Aldosterone System Copyright © 2023 Wolters Kluwer All Rights Reserved Hypertension Person’s BP is above normal limit for sustained period o 90% have essential or primary hypertension Underlying danger o Body organ damage o Increased risk of atherosclerotic vascular disease o Thickening of heart muscle Difficult to diagnose and treat; “silent killer” Copyright © 2023 Wolters Kluwer All Rights Reserved Conditions Related to Untreated Hypertension CAD and cardiac death Stroke Renal failure Loss of vision Copyright © 2023 Wolters Kluwer All Rights Reserved Risk Factors Associated With Hypertension  Increased age  Cigarette smoking  High-salt diet  High intake of alcohol  Low physical fitness  Obesity  Insulin resistance  Psychological stress  Obstructive sleep apnea  Family history Copyright © 2023 Wolters Kluwer All Rights Reserved Hypotension  BP becomes too low  Vital centers in brain and rest of tissues in body may not receive enough oxygenated blood to function  Can progress to shock  Can occur in following situations: o Heart muscle is damaged and unable to pump effectively o Severe blood or fluid loss, when volume drops dramatically o Impairment of autonomic nervous system to increase cardiac output, vascular resistance, or both o Medication-induced hypotension Copyright © 2023 Wolters Kluwer All Rights Reserved Orthostatic Hypotension Lowering of BP when person sits up from lying down or stands from sitting position May be accompanied by dizziness, light-headedness, nausea, changes in vision, and/or syncope o Symptoms caused by decrease in blood flow to brain tissue Increased risk o Older adults o Use of certain medications Copyright © 2023 Wolters Kluwer All Rights Reserved Use of Drugs Affecting Blood Pressure Across the Lifespan #1 Copyright © 2023 Wolters Kluwer All Rights Reserved Use of Drugs Affecting Blood Pressure Across the Lifespan #2 Copyright © 2023 Wolters Kluwer All Rights Reserved Stepped Care Management of Hypertension Step 1: Lifestyle modifications Step 2: Drug therapy added Step 3: Change in drug dose or class or addition of another drug Step 4: Second or third agent or diuretic is added Copyright © 2023 Wolters Kluwer All Rights Reserved Antihypertensive Agents  Work to alter normal reflexes that control BP  Not all patients respond in same way to antihypertensive drugs because of different factors and complicating conditions  Several different types of medication may need to be used in combination  Drugs include o ACE inhibitors o Angiotensin II receptor blockers (ARBs) o Calcium-channel blockers o Vasodilators o Other agents Copyright © 2023 Wolters Kluwer All Rights Reserved Drugs Affecting the RAAS ACE inhibitors ARBs Renin inhibitor Copyright © 2023 Wolters Kluwer All Rights Reserved ACE Inhibitors #1 Benazepril (Lotensin) Lisinopril (Prinivil, Zestril, Qbrelis) Captopril (generic) Moexipril (generic) Enalapril (Epaned, Vasotec) Perindopril (generic) Enalaprilat (generic) Quinapril (Accupril) Fosinopril (generic) Ramipril (Altace) Trandolapril (generic) Copyright © 2023 Wolters Kluwer All Rights Reserved ACE Inhibitors #2  Therapeutic actions o Act in lungs to prevent ACE from converting angiotensin I to angiotensin II, leading to a decrease in blood pressure and in aldosterone production; results in increase in serum potassium and loss of serum sodium and fluid  Indications o Treatment of hypertension, heart failure, left ventricular dysfunction, diabetic nephropathy  Pharmacokinetics o Well absorbed, widely distributed, metabolized in the liver, and excreted in the urine and feces o Cross placenta and enter human milk Copyright © 2023 Wolters Kluwer All Rights Reserved ACE Inhibitors #3 Contraindications o History of allergic reaction o Impaired renal function o Acute heart failure exacerbation o Salt/volume depletion o Pregnancy and lactation Copyright © 2023 Wolters Kluwer All Rights Reserved ACE Inhibitors #4 Adverse effects o Related to the effects of vasodilatation and alterations in blood flow o Generally well tolerated o Serious allergic reactions including angioedema o Hyperkalemia o Captopril, moexipril, perindopril: more serious effects Copyright © 2023 Wolters Kluwer All Rights Reserved ACE Inhibitors #5 Drug–drug interactions o Allopurinol o NSAIDs o Diuretics and other antihypertensive medications o Potassium supplements and potassium-sparing diuretics o Lithium o Drugs that alter RAAS o Other ACE inhibitors, ARBs, renin inhibitor Copyright © 2023 Wolters Kluwer All Rights Reserved ACE Inhibitor Prototype Copyright © 2023 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 stepped care management of hypertension. Copyright © 2023 Wolters Kluwer All Rights Reserved Answer to Question #1 False Rationale: The first step in stepped care management of hypertension involves lifestyle modifications. A diuretic may be added in step 2. Copyright © 2023 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #1 Azilsartan (Edarbi) Candesartan (Atacand) Irbesartan (Avapro) Losartan (Cozaar) Olmesartan (Benicar) Telmisartan (Micardis) Valsartan (Diovan) Copyright © 2023 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #2  Therapeutic actions o Selectively bind with the angiotensin II receptors in vascular smooth muscle and in the adrenal cortex to block vasoconstriction and the release of aldosterone o These actions block BP-raising effects of the RAAS and lower BP  Indications o Used alone or in combination to treat hypertension o Some indicated for treatment of heart failure and after MI o Some have been found to slow progression of renal disease Copyright © 2023 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #3 Pharmacokinetics o Well absorbed; undergo metabolism in the liver by the cytochrome P450 system; excreted in the feces and urine o Cross the placenta o Not known if they enter human milk Copyright © 2023 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #4 Contraindications o Allergy o Pregnancy and lactation Cautions o Hepatic or renal dysfunction o Hypovolemia Copyright © 2023 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blockers #5  Adverse effects o Headache, dizziness, syncope, weakness o GI complaints o Dry mouth and tooth pain o Symptoms of upper respiratory infections and cough o Rash, dry skin, alopecia  Drug–drug interactions o Other antihypertensive medications o Potassium supplements or potassium-sparing diuretic medication o Lithium o NSAIDs Copyright © 2023 Wolters Kluwer All Rights Reserved Angiotensin II Receptor Blocker Prototype Copyright © 2023 Wolters Kluwer All Rights Reserved Renin Inhibitor #1 Aliskiren (Tekturna) Therapeutic action o Directly inhibits renin, leading to decreased plasma renin activity and inhibiting the conversion of angiotensinogen to angiotensin I Pharmacokinetics o Poorly and slowly absorbed from GI tract, metabolized in the liver, excreted in the urine o Crosses the placenta and enters human milk Copyright © 2023 Wolters Kluwer All Rights Reserved Renin Inhibitor #2  Contraindications o Pregnancy and lactation  Adverse effects o Risk of hyperkalemia o Angioedema with respiratory involvement o Renal impairment  Drug–drug Interactions o Furosemide o Other antihypertensive medications o ACE inhibitors, ARBs, potassium-sparing diuretics Copyright © 2023 Wolters Kluwer All Rights Reserved Calcium-Channel Blockers #1 Decrease BP, cardiac o Nifedipine (Procardia XL) work load, myocardial o Nisoldipine (Sular) oxygen consumption o Verapamil (Calan SR) Drugs o Clevidipine (Cleviprex): o Amlodipine (Katerzia, IV only for short-term Norvasc) management o Diltiazem (Cardizem LA, Cartia XT, others) o Felodipine (generic) o Isradipine (generic) o Nicardipine (generic) Copyright © 2023 Wolters Kluwer All Rights Reserved Calcium-Channel Blockers #2  Therapeutic actions o Inhibit movement of calcium ions across the membranes of myocardial and arterial muscle cells, altering action potential and blocking muscle cell contraction  Indications o Treatment of hypertension, angina  Pharmacokinetics o Well absorbed, metabolized in the liver, and excreted in the urine o Cross the placenta and enter human milk Copyright © 2023 Wolters Kluwer All Rights Reserved Calcium-Channel Blockers #3  Contraindications o Allergy o Nondihydropyridine calcium-channel blockers: heart block or sick sinus syndrome, heart failure, acute MI o Pregnancy and lactation  Adverse effects o Related to effects on cardiac output o CNS effects o GI effects o CV effects o Skin flushing and rash Copyright © 2023 Wolters Kluwer All Rights Reserved Calcium-Channel Blockers #4 Drug–drug interactions o Vary with each drug Drug–food interactions o Grapefruit juice Copyright © 2023 Wolters Kluwer All Rights Reserved Calcium-Channel Blocker Prototype Copyright © 2023 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 secretion C. Increase in serum sodium and fluid D. Increase in blood pressure Copyright © 2023 Wolters Kluwer All Rights Reserved Answer to Question #2 B. Decrease in aldosterone secretion Rationale: ACE inhibitors act in the lungs to prevent ACE from converting angiotensin I to angiotensin II, a powerful vasoconstrictor and stimulator of aldosterone release. This action leads to a decrease in BP and in aldosterone secretion with a resultant increase in serum potassium and a loss of serum sodium and fluid. Copyright © 2023 Wolters Kluwer All Rights Reserved Vasodilators #1 Most are reserved for use in severe hypertension, refractory hypertension, or hypertensive emergencies Drugs o Hydralazine (generic) o Minoxidil (generic) o Nitroglycerin (generic) o Nitroprusside (Nitropress) Copyright © 2023 Wolters Kluwer All Rights Reserved Vasodilators #2  Therapeutic actions o Act directly on vascular smooth muscle to cause muscle relaxation, leading to vasodilatation and drop in BP  Indications o Severe hypertension that has not responded to other therapy  Pharmacokinetics o Rapidly absorbed and widely distributed, metabolized in the liver, and primarily excreted in the urine o Cross placenta and enter human milk Copyright © 2023 Wolters Kluwer All Rights Reserved Vasodilators #3  Contraindications o Known allergy o Any condition that could be exacerbated by sudden fall in BP o Pregnancy and lactation  Cautions o Peripheral vascular disease o CAD o Heart failure o Tachycardia Copyright © 2023 Wolters Kluwer All Rights Reserved Vasodilators #4 Adverse effects o Related to changes in BP o Cyanide toxicity Drug–drug interactions o Varies by individual drug; check each before use Copyright © 2023 Wolters Kluwer All Rights Reserved Vasodilator Prototype Copyright © 2023 Wolters Kluwer All Rights Reserved Diuretics Increase excretion of sodium and water from the kidney to lower BP See Chapter 51 for detailed discussion of these agents Often one of the first agents tried in mild hypertension Usually tolerated well by most patients Diuretics used to treat hypertension: o Thiazide and thiazidelike diuretics o Potassium-sparing diuretics Copyright © 2023 Wolters Kluwer All Rights Reserved Sympathetic Nervous System Blockers Block effects of sympathetic nervous system See Chapter 31 for detailed discussion of these agents Drugs: o Beta-blockers o Alpha- and beta-blockers o Alpha-adrenergic blockers o Alpha1-blockers o Alpha2-agonists Copyright © 2023 Wolters Kluwer All Rights Reserved Question #3 For which drug will the nurse need to caution patients against drinking grapefruit juice? A. Irbesartan (Avapro) B. Aliskiren (Tekturna) C. Clevidipine (Cleviprex) D. Moexipril (generic) Copyright © 2023 Wolters Kluwer All Rights Reserved Answer to Question #3 C. Clevidipine (Cleviprex) Rationale: Clevidipine (Cleviprex) is a calcium- channel blocker. The calcium-channel blockers are a class of drugs that interact with grapefruit juice. When grapefruit juice is present in the body, the concentrations of calcium-channel blockers increase, sometimes to toxic levels. Advise patients to avoid drinking grapefruit juice if they are taking a calcium- channel blocker. If a patient on a calcium-channel blocker reports toxic effects, ask whether they have been drinking grapefruit juice. Copyright © 2023 Wolters Kluwer All Rights Reserved Antihypotensive Agents Sympathetic adrenergic agonists or vasopressors Blood pressure–raising agents Droxidopa (Northera) Copyright © 2023 Wolters Kluwer All Rights Reserved Sympathetic Adrenergic Agonists or Vasopressors #1 First choice for treating severe hypotension or shock Sympathomimetic drugs discussed in detail in Chapter 30 Therapeutic actions and indications o React with sympathetic adrenergic receptors to cause effects of sympathetic stress response o Increase BP and may restore balance to CV system while underlying cause of shock is treated Copyright © 2023 Wolters Kluwer All Rights Reserved Sympathetic Adrenergic Agonists or Vasopressors #2 Adverse effects o Effects of stimulation of sympathetic system o Use with caution with any disease that limits blood flow Drug–drug interactions o Other agents that increase HR and BP Copyright © 2023 Wolters Kluwer All Rights Reserved Blood Pressure–Raising Agent: Midodrine #1  Therapeutic actions and indications o Activates alpha-receptors in arteries and veins to produce increase in vascular tone, increase in BP o Symptomatic treatment of orthostatic hypotension in patients whose lives are impaired by the disorder and who have not responded to other therapy  Pharmacokinetics o Rapidly absorbed from GI tract; metabolized in liver and excreted in urine o Not known if it enters human milk Copyright © 2023 Wolters Kluwer All Rights Reserved Blood Pressure–Raising Agent: Midodrine #2  Contraindications o Supine hypotension or pheochromocytoma  Cautions o Severe heart disease o Acute renal disease o Urinary retention o Thyrotoxicosis o Pregnancy and lactation o Visual problems o Renal or hepatic impairment Copyright © 2023 Wolters Kluwer All Rights Reserved Blood Pressure–Raising Agent: Midodrine #3 Adverse effects o Related to stimulation of alpha-receptors Drug–drug interactions o Cardiac glycosides, beta-blockers, alpha- adrenergic agents, corticosteroids Copyright © 2023 Wolters Kluwer All Rights Reserved Droxidopa #1  Indicated for treatment of orthostatic dizziness, light- headedness, “about to black out” feeling in adults with symptomatic neurogenic orthostatic hypotension  Therapeutic actions and indications o Metabolized to norepinephrine by dopa decarboxylase o Actions on BP thought to be related to norepinephrine effects causing vasoconstriction  Pharmacokinetics o Absorbed through GI tract; widely distributed; metabolized by normal catecholamine pathways; excreted in urine Copyright © 2023 Wolters Kluwer All Rights Reserved Droxidopa #2  Contraindications o History of allergy  Cautions o History of CV issues o Renal impairment o Breast or chestfeeding  Adverse effects o Related to sympathetic effects of the drug  Drug–drug interactions o Dopa decarboxylase inhibitors Copyright © 2023 Wolters Kluwer All Rights Reserved