Antihypertensive Drugs PDF

Antihypertensive Drugs Dr. Charlotte Stephenson Revised by Farah Villanueva, MSN, APRN, FNP-C Texas Woman's University NURS 3813 Hypertension • WHO estimates 1.28 billion adults aged 30-79 years worldwide have hypertension • About 50% of adults are unaware they have hypertension • Hypertension is...

Antihypertensive Drugs Dr. Charlotte Stephenson Revised by Farah Villanueva, MSN, APRN, FNP-C Texas Woman's University NURS 3813 Hypertension • WHO estimates 1.28 billion adults aged 30-79 years worldwide have hypertension • About 50% of adults are unaware they have hypertension • Hypertension is known as the "silent killer" because it is a major cause of • Premature death • MI • HF • CVA • Renal disease Hypertension Definition •According to the ACC/AHA guidelines, HTN is: • SBP > 130 or • DBP > 80 mm Hg • Based on the average of at least 2 separate BP measurements Overview of BP Regulation BP = CO x PVR Cardiac Output • CO = HR x SV • Heart rate • CNS, hormones, and ions • Stroke volume • Preload = Blood volume • Contractility • Afterload = Resistance Peripheral Vascular Resistance • Vascular tone • Neural, hormonal, and local factors BP Regulation Continued • Neural • Sympathetic nervous system (SNS) • Epinephrine/norepinephrine • Vasomotor center in brain • Baroreceptors/Chemoreceptors • Vascular • Vasoconstrictors • Endothelin-1, angiotensin II, PDGF • Vasodilators • Nitric oxide • Vascular remodeling • Hormonal • Vasopressin (ADH) • Renin-angiotensin-aldosterone (RAA) system Etiology • Primary/Essential HTN • Most common • Accounts for 90-95% of cases • Cause unknown • Multifactorial • Associated with: • Increased SNS activity (stress) • Altered RAAS • Sodium retention • Insulin resistance/ DM • Obesity Etiology Continued • RISK FACTOR for primary HTN • R – race • I – increase Na or ETOH intake • S – smoking or stress • K – K+ is low • • • • • • F – family history A – advanced age C – cholesterol is high T – too much caffeine O – obesity R – restricting activity • Modifiable vs non-modifiable risk factors Etiology Continued • Secondary HTN • Not as common (~5% of cases) • Results from another condition • Heart defects – ex. coarctation of the aorta • Renal – ex. renal artery stenosis, polycystic kidney disease, etc. • Endocrine – ex. hyperaldosteronism, hyperthyroidism, etc. • Respiratory - OSA • CNS – high intracranial pressure • Pregnancy – pre-eclampsia/eclampsia • Medication/drug induced • Sympathomimetics, asthma medications, NSAIDs, etc. • Elicit drugs • Can sometimes be resolved by managing the underlying condition or cause Clinical Manifestations • No symptoms may be present • May go undetected for some time • Symptoms eventually reflect target organ damage • C – change in vision/chest pain • H – headache • I – irritability • E – epistaxis • F – forgetfulness • Complications • Angina, MI, HF • Stroke • End organ damage • Aneurysms Guidelines for Therapy JNC 8 Guidelines • Joint National Committee 8 Guidelines (JNC 8) • Healthy habits or lifestyle modifications recommended for all • Elevate BP – lifestyle modifications are recommended • Stage 1 – initiation of antihypertensive medication based on CVD risk • Stage 2 – antihypertensive medication prescribed Normal Promote optimal lifestyle habits Elevated Stage 1 HTN Stage 2 HTN Lifestyle changes Clinical CVD or risk for CVD Lifestyle changes+ BP lowering medications No Yes Lifestyle changes Lifestyle changes + BP lowering medications Lifestyle Modifications Lifestyle Modification Reduction of SBP Weight loss Goal is ideal body weight - 5 mm Hg/10 kg loss DASH diet Consume a diet rich in fruits, vegetables, whole grains, and low-fat dairy Reduce saturated and total fat - 11 mm Hg Reduced intake of sodium Optimal goal: <1,500 mg/day - 5 to 6 mm Hg Enhanced intake of potassium Aim for 3,500-5,000 mg/day - 4 to 5 mm Hg Physical Activity Aerobic exercise 90-150 min/week - 5 to 8 mm Hg Resistance training 90-150 min/week - 4 to 5 mm Hg Men: ≤ 2 drinks/day Women: ≤ 1 drink/day - 4 mm Hg Moderation in ETOH Drug Management • Hypertension Treatment ABCDs • A - ACEI/ARBs • B - Beta blockers • C - Calcium channel blockers • D - Diuretics Diuretics • Different Classes • Loop • Thiazide • Potassium sparing • Thiazide diuretics are the first-line drug for uncomplicated HTN • Prototype: hydrochlorothiazide (HCTZ) • Often used in combination with other drugs Diuretics Continued • Action • Inhibits Na/Cl channel in distal convoluted tubule • Increases renal excretion of Na and Cl • Increases urine output • Decreases blood volume • MOA unknown but causes vasodilation Diuretics Continued • Advantages • Inexpensive • Overall well tolerated • Useful for pts with • Predisposition of kidney stones • Osteopenia • Possible SE • Orthostatic hypotension • Hyponatremia • Hypercalcemia • Hypokalemia • Hyperuricemia • Hyperglycemia • Nursing considerations • Take medication during the day • Monitor • I&Os • Weight • Labs • Patient education • Change positions and get up slowly • Encourage K+ rich foods • Avoid in patients with • Sulfa allergy • Gout Based on your nursing knowledge of how thiazide diuretics work, which patients below would benefit from these types of medications? Select all that apply: Practice Question A. B. C. D. E. A patient with a glomerular filtration rate (GFR) of less than 30 cc/hr. A patient with a recurrent history of renal calcium calculi. A patient with primary hypertension. A patient with heart failure and frequent gout attacks. A patient with diabetes that has uncontrolled hyperglycemia. Angiotensin-Converting Enzyme (ACE) Inhibitors • Prototype: captopril (Capoten) • Other drugs: lisinopril, benazapril • Suffix: -pril • "coughing prils" • Action • Blocks enzyme that converts angiotensin I to angiotensin II • Inhibits the breakdown of bradykinin = prolongs vasodilating effects • Use • HTN • DM • Prevent/reverse heart remodeling with HF • Post MI ACE-I Continued SE • C – cough • A – angioedema • P – pregnancy contraindication • T – taste change • O – orthostatic hypotension/ other (fatigue or rash) • P – proteinuria • R – renal insufficiency contraindication • I – increases potassium • L – lowers BP/ leukopenia ACE-I Continued • Nursing considerations • Monitor labs and electrolytes • Consult provider if cough becomes bothersome • Avoid salt substitutes with K+ or K+ rich foods • BLACK BOX WARNING - Do not use if pregnant or trying to get pregnant • Women of childbearing years should be on birth control if taking this medication • Don’t take with • ARBs Angiotensin II Receptor Blockers • Prototype: losartan (Cozaar) • Other drugs: valsartan, candasartan • Suffix: - sartan • "sartan sisters" • Action • Blocks angiotensin II at various receptor sites • Prevents effects of vasoconstriction and aldosterone secretion • Use • HTN • DM • HF • Post MI ARBs Continued • Advantages • Does not cause cough • Angioedema rare • SE • Similar to ACE-I • BLACK BOX WARNING – Pregnancy • Nursing considerations • Don't take with an ACE inhibitor Your patient is taking an ACE inhibitor to manage their high blood pressure. Which finding below requires immediate nursing action? Practice Question A. B. C. D. Urinary output is 190 ml within 4 hours Patient R has a persistent dry, cough EKG shows tall, peaked T waves Patient has a negative Chvostek’s sign. Calcium Channel Blockers • 2 Categories • Dihydropyridines • Non-dihydropyridines • Calcium channel blockers are Very Nice Drugs. • V – verapamil • N – nifedipine • D – diltiazem CCBs Continued • Dihydropyridines • Prototype: amlodipine (Norvasc) • Suffix: -dipine • Action • Inhibits the influx of calcium ions in the smooth muscles of the blood vessels • Relaxation and dilation of arteries • Metabolism • Cytochrome P450 3A4 (CYP3A4) • Use • • • • HTN African Americans Angina Conditions with vasoconstriction/vasospasms CCBs Continued • Non-dihydropyridines • verapamil (Verelan) • diltiazem (Cardizem) • Action • Inhibits the influx of calcium ions in cardiac muscles and pacemaker cells • Decrease conduction = decrease HR • Decrease contractility • Metabolism • Cytochrome P450 3A4 (CYP3A4) • Use • HTN • Angina • Tachyarrhythmias CCBs Continued DHP Non-DHP • SE • SE • Edema • Peripheral – hands, ankle, or feet • Pulmonary – particularly with HF patients • Flushing • Reflex tachycardia • Bradycardia • Rare • Arrhythmias • Heart block • Heart failure CCBs Continued • Caution use with non-DHP • Bradycardia • Heart failure • Beta-blockers • Educate patient on possible food/drug interactions • CYP3A4 inducers: St. John's Wort • Decreases effectiveness • CYP3A4 inhibitors: grapefruit juice • Increases plasma concentration • Educate patient on how to relieve edema with DHP • Compression stockings • Encourage walking • Elevating extremity Practice Question A patient has been prescribed amlodipine (Norvasc) for hypertension. The nurse should educate the patient about which potential side effects? A. B. C. D. Bradycardia and depressed contractility Dizziness, headaches, and reflex tachycardia Impaired electrical conduction Coronary vasospasms Beta-adrenergic Blockers • Usually not initial therapy unless specifically indicated • Prototype: propranolol (Inderal) • Suffix: -olol > lo lo =beta blockers • Types • Selective • metoprolol, atenolol, esmolol • Non-selective • propranolol, timolol • Action • Blocks epinephrine and norepinephrine at beta-adrenergic receptors • Decrease HR • Decrease contraction BBs Continued • Use • • • • HTN Stable angina Tachyarrhythmias Stable HF • BLACK BOX WARNING – Abrupt discontinuation caused exacerbation of angina, dysrhythmias, and MIs with patients who had CAD • SE/Nursing considerations • Think BETA BLOCK BBs Continued - SE/Nursing Considerations • B – bradycardia and heart blocks • Medication parameters • Monitor HR and rhythm • E – exacerbates HF • Monitor weight, I&O, edema, lung sounds • T – taper off • Don't stop abruptly; Can lead to rebound HTN and angina • A – asthma and COPD use with caution • Don't use non-selective BB • B – blood glucose masking • Masks S&S of hypoglycemia - no tremors or tachycardia • Educate DM patients to check BG regularly • L – lowers BP • Monitor BP and follow medication parameters • O – orthostatic hypotension • Dangle and slowly go from sitting to standing to prevent dizziness • C – circulation may be impaired • Caution use for those with PVD • Can cause ED • K – know S&S of overdose • Bradycardia, heart block, hypotension • Mental status change Adjuvant Medications • Sympathetic nervous system (SNS) • Alpha-adrenergic receptor blockers: prazosin • RAAS • Direct renin inhibitors: aliskiren (Tekturna) • Aldosterone antagonist • Direct vasodilators • nitroprusside (Nitropress) • Hydralazine (Hydra-Zide, BiDil) Review in your text Hypertensive Crisis Hypertensive Urgency Hypertensive Emergency • BP >180/120 mm Hg • BP >180/120 mm Hg • No target organ damage • Presence of ongoing target organ damage • Severe headache • Difficulty speaking • Vision changes • Weakness • Chest pain • Shortness of breath • Hematuria Outpatient management = Urgent care Inpatient management = ER/hospital Treatment • BP lowered in hours/days Treatment • Controlled reduction of BP within mins/hours Hypertensive Emergency Management • BP lowered slowly over 24-48 hours with oral meds like labetalol (beta-blocker) and/or IV meds like sodium nitroprusside • Must have controlled lowering but not to normal BP levels • Rapid BP lowering causes marked reduction in organ flow = ischemia Direct Acting Vasodilator • Prototype: sodium nitroprusside (Nitride) • Action • Directly relaxes smooth muscle in blood vessels = dilation and decreased peripheral vascular resistance • Use • Effective in managing a hypertensive emergency • SE • nausea, agitation, muscle twitching • Nursing considerations • Given IV and requires continuous BP monitoring • Rapid onset and short duration of action • Converts to thiocyanate in liver: can have cyanide toxicity (coma, dilated pupils, pink color) • Monitor lab: thiocyanate levels General Nursing Considerations • Obtain complete health history • Medical history • Family history • Medications • Lifestyle • Diet • Monitor labs • Electrolytes • CBC • BUN/Cr/Urinalysis • LFTs • Lipid panel • Medication administration principles • Monitor BP before and after administration of drug • Start BP medications on lowest effective dose to avoid possible side effects • If BP unmanaged with monotherapy, use combination therapy at lower doses • Taper slowly and never discontinue abruptly Patient Education • • • • • • • • Reduce Na intake Reduce caffeine intake Limit alcohol Quit smoking Weight management Limit vasodilating baths/showers, hot tubs, or saunas Assess compliance Don't stop medications abruptly References • Frandsen, G & Pennington, S.S. (2021). Abrams’ clinical drug therapy: Rationales for nursing practice (12th ed.). Philadelphia, PA: Wolters Kluwer. THANK YOU What questions do you have?