DRUGS AFFECTING THE CARDIOVASCULAR SYSTEM

DRUGS AFFECTING THE CARDIOVASCULAR SYSTEM

DRUGS AFFECTING BLOOD PRESSUREANTIHYPERTENSIVE AGENTSDoes not cure HPN but maintains the BP within normal range to prevent the damage that HPN can cause

DIURETICSDrugs that increase the excretion of sodium and water from the kidneyOften the first agents tried in mild hypertension-> affecting the blood sodium levels and blood volumeDecrease BP and edemausually given at morning

HPN- retention of sodium and water; RAA mechanism; preload/afterloadWeight reduction/restricted Na intake2DRUGS AFFECTING BLOOD PRESSURE CARBONIC ANHYDRASE INHIBITORS - Acetazolimide (Diamox) - increase Na+, K+, & HCO3 secretion, along with it is H2O - metabolic acidosis OSMOTIC DIURETIC - Mannitol - Increase osmotic pressure of the glomerular filtrate. - hypotension- decreasing intracranial and intraocular pressures3DRUGS AFFECTING BLOOD PRESSURE THIAZIDE DIURETICS - hydrochlorothiazide - blocks Na and K reabsorption; reabsorb Ca (K-wasting) - hypercalcemia, hypokalemiaAdvise the client to rise slowly from a sitting to a standing position to avoid dizziness.Diet: rich in K LOOP DIURETICS - Furosemide (Lasix) - blocks Na, K, and Ca reabsorption - hypocalcemia POTASSIUM SPARING DIURETICS - Spironolactone (Aldactone) - excrete Na and water but it reabsorb K - hyperkalemia4DRUGS AFFECTING BLOOD PRESSURESYMPATHETIC NERVOUS SYSTEM BLOCKERSA. Beta-blockers- block vasoconstriction, decrease HR, decrease cardiac muscle contraction, and tend to increase blood flow to the kidneys -> decrease in the release of reninB. Alpha- and beta-blockers- useful in conjunction with other agents and tend to be powerful -> blocking all sympathetic receptors- complains of fatigue, loss of libido, inability to sleep, GI, GU disturbances -> unwilling to continue5DRUGS AFFECTING BLOOD PRESSURESYMPATHETIC NERVOUS SYSTEM BLOCKERSC. Alpha-adrenergic blockers- inhibit alpha1-adrenergic receptors, decreasing sympathetic tone in the vasculature and cause vasodilation -> lowered BPD. Alpha1-blockers- used to treat HPN-> blocks alpha1 receptors -> decreases vascular tone -> vasodilation -> decrease BPE. Alpha2-agonists -stimulate alpha2-receptors in the CNS -> inhibit cardiovascular centers -> decrease in sympathetic outflow -> decrease BP- associated with CNS, GI effects and dysrhythmias6DRUGS AFFECTING BLOOD PRESSUREANGIOTENSIN-CONVERTING ENZYME (ACE) INHIBITORS Blocks the conversion of angiotensin I to angiotensin II in the lungs-> stops the renin-angiotensin system before vasoconstriction can occur or aldosterone can be release. Can be used alone or with diureticsbenazepril (Lotensin), enalapril (vasotec), lisinopril (Zestril), captopril (Capoten)

7DRUGS AFFECTING BLOOD PRESSURETHERAPEUTIC ACTIONprevent ACE from converting angiotensin I to angiotensin II (powerful vasoconstrictor and stimulator of aldosterone release) -> decrease in BP and aldosterone secretion -> increase in K and loss of Na and fluids

USES:HPN, CHF (with digoxin, diuretics)Related to decrease in workload associated with decrease in peripheral resistance and blood volumePHARMACOKINETICS:A: well-absorbed; D: widely distributed; M: liver; E: urine and fecesShould not be used during pregnancy

8DRUGS AFFECTING BLOOD PRESSUREADVERSE EFFECTS:Related to effects of vasodilation and alterations in blood flow (tachycardia, chest pain, angina, CHF, arrhythmias; GI irritation, ulcers, constipation, liver injury, proteinuria, cough -> r/t effects in the lungsNURSING CONSIDERATIONS:- not to discontinue medications because it can cause rebound hypertension.- avoid using K+ sparing diuretics.(overuse can lead to hyperkalemia)-should be taken with empty stomach (1 or 2 hours after meals)9DRUGS AFFECTING BLOOD PRESSUREANGIOTENSIN II RECEPTOR BLOCKERSselectively bind the angiotensin II receptors in blood vessels to prevent vasoconstriction and in the adrenal cortex to prevent the release of aldosterone that is caused by reaction of these receptors with angiotensin IIlead to decrease in blood pressure caused by a decrease in total peripheral resistance and blood volumeirbesartan (Avapro), losartan (Cozaar), olmesartan (Benicar), telmisartan (MIcardis)10DRUGS AFFECTING BLOOD PRESSUREACTIONS: block vasoconstriction and the release of aldosterone -> blocks the blood-pressure rising effects of the renin-angiotensin system and lower BP

USES: HPN, CHF, slows down renal disease associated with HPN and DMPHARMACOKINETICS:A: well-absorbed; D: ; M: liver; E: urine and feces(not used during pregnancy-> fetal abnormalities and death)11DRUGS AFFECTING BLOOD PRESSURECONTRAINDICATIONS AND CAUTIONS:Allergy, pregnancy, lactation, hepatic/renal dysfunctionADVERSE EFFECTS:Headache, dizziness, syncope, weakness associated with drop in BP/hypotensionDiarrhea, abdominal pain, nausea, dry mouth, tooth painCough, rashes, dry skin12DRUGS AFFECTING BLOOD PRESSURECalcium Channel BlockersPrevent the movement of Ca into the cardiac and smooth muscle cells when cells are stimulated -> interfere with the muscle cells ability to contract -> loss of smooth muscle tone -> vasodilation -> decrease in peripheral resistance -> decrease in BP, cardiac workload, myocardial oxygen consumptionAlso effective in treatment of anginaamlodipine (Norvasc), diltiazem (Cardizem), nicardipine (Cardene), nifedipine (Procardia), verapamil13DRUGS AFFECTING BLOOD PRESSUREACTIONS:inhibit the movement of Ca ions across the myocardial and arterial muscle cells -> altering the action potential -> blocking contraction -> depresses myocardial contractility -> relaxes and dilates arteries -> fall in BPPHARMACOKINETICS:A: well-absorbed; D: placenta/BM/pregnancy; M: liver; E: urineCONTRAINDICATIONS AND CAUTIONS: Allergy; renal/hepatic dysfunction; pregnancy and lactationADVERSE EFFECTS:Dizziness, light-headedness, headache, fatigue; nausea, hepatic injury; hypotension, bradycardia, peripheral edema14DRUGS AFFECTING BLOOD PRESSUREVASODILATORSRelaxation of the vascular smooth muscles -> decreasing peripheral resistance -> reducing BPSevere HPN, hypertensive crisisdiazoxide (Hyperstat), hydralazine (Apresoline), minoxidil (Loniten), nitroprusside (Nitropress)ACTIONS:act directly on vascular smooth muscle to cause muscle relaxation -> vasodilation -> drop in BP15DRUGS AFFECTING BLOOD PRESSUREUSES:treatment of severe HPN that has not responded to other therapyPHARMACOKINETICS:A: rapidly absorbed; D: widely distributed (placenta/BM); M: liver; E: urine

CONTRAINDICATIONS/CAUTIONS:same=)ADVERSE EFFECTS:dizziness, anxiety, headache, tachycardia, chest pain, edema skin rash and lesion, nausea, vomiting16DRUGS AFFECTING BLOOD PRESSURECARDIOTONIC DRUGSInotropic drugs -> affects intracellular Ca levels in the heart muscle -> increased contractility -> increase CO -> increase renal blood flow and increase urine production -> decrease renin release -> breaking the RAS -> increases UO -> decrease BV -> decrease workload of the heart/relieve CHF17DRUGS AFFECTING BLOOD PRESSUREI. Cardiac Glycosides- from foxglove plant or digitalis plants*digoxin (Lanoxin)- most often used to treat CHF- very rapid onsetPHARMACOKINETICS:- A: oral/parenteral; D: wide; M: liver; E: urine (safe to hepatic dysfunction/caution to renal dysfunction)- very narrow margin of safety (Th dose is very close to To dose) -> digoxin toxicity -> extra care-> digibind (antidote)18DRUGS AFFECTING BLOOD PRESSUREACTIONS:Decrease in the myocardial workload and relief CHFUSES:CHF, atrial flutter, atrial fibrillation, paroxysmal atrial tachycardiaADVERSE EFFECTS:Headache, weakness, drowsiness and vision changes (halo-> toxicity), GI upset and anorexia, arrhythmia19DRUGS AFFECTING BLOOD PRESSURENURSING CONSIDERATIONS: Monitor for toxicity as evidence by : -nausea, vomiting, anorexia, halo vision, confusion, bradycardia and heart blocks . Do not administer if pulse is less than 60 bpm. Should be caution in patient with hypothyroidism and hypokalemia. Antidote : Digi-bind Phenytoin is the drug of choice to manage digitalis-induced arrhythmia.once dailyfurosemide + digitalis = increase action of digoxin20ANTIANGINAL AGENTSUsed to help restore the supply-demand ratio in O2 delivery to the myocardium when rest is not enoughWorking by: (1) dilating blood vessels ->increasing O2; and (2) decreasing workload of the heart-> decreasing O2 demandNitrates, beta-adrenergic blockers, Ca channel blockers

All are effective and sometimes used in combination -> good control of angina pain21ANTIANGINAL AGENTSNitratesAct directly on smooth muscle to cause relaxation and to depress muscle tone -> do not have action on nervesFast actionRelax and dilate blood vessels -> increasing blood flow and lowers systemic BP because of decrease peripheral resistanceVasodilation -> blood pool in veins and capillaries -> decreasing the BV that the heart has to pump; while relaxation of the vessels decreases the resistance the heart has to pump against (afterload)Combination of these effects greatly reduces the cardiac workload and the demand for O2->O2 rationitroglycerin (NItrostat), amyl nitrate, isosorbide dinitrate (Isordil), isosorbide mononitrate (Imdur)22ANTIANGINAL AGENTSnitroglycerin nitrate of choice in acute angina attacksublingual, IV, transdermally, topically, transmucosalrapidly absorbed and has an onset within minutescan be used for prevention

isosorbide dinitrate (Isordil), isosorbide mononitrate (Imdur)oral drugs; slower onset; may last up to 4 hourstaken before chest pains begin in anticipated stress or exertionnot drugs of choice during attacks23ANTIANGINAL AGENTSACTIONS:causes direct relaxation of smooth muscle -> decrease in venous return -> decrease in arterial pressure -> reduce cardiac workload and decrease oxygen consumption

USES:prevention and treatment of angina pectorisPHARMACOKINETICS:A: varies, rapid; D: wide; M: liver; E: urine (not recommended during pregnancy and breast feeding)24ANTIANGINAL AGENTSCONTRAINDICATIONS AND CAUTIONS:allergy; severe anemia (decreased CO), head trauma (relaxation of vessels can lead to bleeding), pregnancy and lactationcaution on hepatic/renal diseases, hypotension and hypovolemia -> limited COADVERSE EFFECTS:related to vasodilation and decrease in blood flow (common) headache, dizziness, weakness; nausea, vomiting, incontinence; hypotension; tachycardia, syncope, angina25ANTIANGINAL AGENTSNursing Considerations : 1. Transdermal patch apply the patch to a hairless area using a new patch and different site each day.remove the patch after 12-24 hours, allowing 10-12 hours patch free each day to 2. Sublingual medications :note the BP before giving the medication.offer sips of water before giving because dryness may inhibit absorption.one tablet for pain and repeat every 5 mins. for a total of three doses; if not relieved after 15 mins., seek medical help.stinging or burning sensation indicates that the tablet is fresh.

prevent tolerance.2. instruct patient not to swallow the pill sustained release medications should be swallowed and not to be crush. protect the pills from light.26BETA- BLOCKERSblocks the stimulatory effects of the SNSnonselective(vasodilation, bronchoconstriction)block the beta-adrenergic receptors and vasoconstriction (->BP) prevent the increase in HR prevent increase in myocardial contractioncombination with nitrates to increase exercise tolerancelower dose than in treating HPNnot recommended to diabetes, vascular disease, COPDmetoprolol, propranolol, nadolol27BETA- BLOCKERSADVERSE EFFECTS:Related to blockade of SNSDizziness, fatigue, emotional disturbances; gastric pain, nausea, vomiting, diarrhea; CHF, decreased CO, arrhythmias; bronchospasms, dyspnea, coughDRUG INTERACTIONS:Clonidine withdrawal (combined with beta-blockers) -> hypertension -> avoid combinationNSAIDS -> decreased antihypertensive effectsEpinephrine -> initial HPNOHA/insulin -> change in blood glucose28CALCIUM CHANNEL BLOCKERSPrevent the movement of calcium into the cardiac and smooth muscle cells ->interfering with contraction-> loss of smooth muscle tone -> vasodilation -> decreased peripheral resistance -> decreases venous return -> decrease afterload -> decrease cardiac workload and oxygenationamlodipine (Norvasc), diltiazepam (Cardizem), nicardipine (Cardene), nifedipine (Adalat, Calcibloc), verapamil (Isoptin)29CALCIUM CHANNEL BLOCKERSACTIONS:Inhibit movement of calcium ions across myocardial and arterial muscle cellsUSES:Angina, hypertension, arrhythmiasPHARMACOKINETICS:A: well-absorbed; M: liver; E: urine (fetal toxicity)30CALCIUM CHANNEL BLOCKERSCONTRAINDICATIONS AND CAUTIONS:Allergy, pregnancy and lactation, renal/hepatic dysfunctionADVERSE EFFECTS:Dizziness, light-headedness, headache, fatigue; nausea and hepatic injury; hypotension, bradycardia, edema NURSING CONSIDERATIONS:Administer between meals to enhance absorption.Take clients pulse rate before each dose, withhold if pulse is below 60 bpm.Refer for signs of congestive heart failure.31