CARDIOVASCULAR SYSTEM PT.1

oh my dis side-travis scott & quavo

renin

produced by JG cells. stimulated by decline in systemic blood pressure and/or SNS stimulation. converts plasma protein angiotensinogen to angiotensin 1

angiotensin converting enzyme (ACE)

converts angiotensin 1 to angiotensin 2

angiotensin 2

stimulates adrenal cortex to secrete aldosterone, which reabsorbs salt and water to increase BP and also acts as a vasoconstrictor.

antidiuretic hormone (ADH)

stimulated by angiotensin 2 in the RAAS system; works to increase water reabsorption and as a vasoconstrictor to increase blood pressure.

captopril (ACE inhibitors)

treats HTN, heart failure, diabetic neuropathy, and left ventricular dysfunction. works by blocking angiotensin 2 production, allowing for vasodilation, excretion of Na and water, and retention of potassium by blocking release of ADH. an oral medication. ADRs include severe hypotension in clients with preexisting HTN, on diuretics, or on low sodium diets; rash, metallic taste, hyperkalemia (causing dysrhythmias), neutropenia, and a dry, non productive cough. angioedema may also occur in allergic reactions. start client’s on a low dose and increase gradually. monitor BP, K⁺ levels, CBC, and WBC. client should report any ADRs, not use salt subs, and report signs of infection. teratogenic.

losartan (A2 receptor blockers)

treats HTN and prevents stroke, along with treating diabetic neuropathy. blocks angiotensin 2 receptors, resulting in vasodilation, urinary excretion of Na and water, and retention of K⁺. an oral medication. ADRs include angioedema, headache, hypotension, insomnia, and dizziness. should monitor BP and treat angioedema if necessary with diphenhydramine or epinephrine. client should report any signs of allergic reaction. teratogenic. not recommended for those with hyperkalemia or liver/renal disorders.

eplerenone (aldosterone antagonists)

treats HTN and manifestations of HF (fluid overload). blocks aldosterone receptors , resulting in Na and water excretion and K⁺ retention (lowering blood volume and pressure). an oral medication. ADRs include s/s of hyperkalemia including irregular HR, palpitations, muscle twitching, weakness, paresthesia, dysrhythmias, cramps, and diarrhea. monitor patients for these s/s, along with K⁺ levels, BUN, and creatinine. patients should avoid salt subs. not recommended for preexisting hyperkalemia, decreased renal function, or with other drugs that increase K⁺ levels.

aliskiren (direct renin inhibitors)

inhibits renin and activation of A1, causing vasodilation and excretion of Na and water with K⁺ retention. treats HTN. ADRs include hyperkalemia, cough, angioedema, and GI distress. monitor K⁺, BUN, creatinine, and s/s of hyperkalemia. client should report any ADRs and avoid salt subs and high fat meals before administration. teratogenic and not recommended for patients with decreased renal function.

nifedipine (calcium channel blockers)

treats HTN, angina, and dysrhythmias. significantly blocks Ca⁺ channels in smooth muscle cells of peripheral arterioles and minimally blocks channels in cardiac arteries, resulting in vasodilation and lowered blood pressure. ADRs include reflex tachycardia, vasodilation that can cause headaches and dizziness, edema, arrhythmias, and gingival hyperplasia. monitor HR and BP (hold if too low), for vasodilatory effects, and for peripheral edema. client should report any ADRs, practice good dental hygiene, and avoid grapefruits. not recommended for patients with low BP or other heart complications.

reflex tachycardia

compensatory increase of HR by low pressure detection from baroreceptors. occurs when blood pressure is dramatically lowered.

alpha 1 and beta 1 receptors

cause vasoconstriction, increased contractility and rate of the heart, and increase blood pressure.

alpha 2 receptors

cause vasodilation and lower blood pressure

beta 2 receptors

cause bronchodilation

doxazosin (alpha 1 blockers)

treats HTN and BPH by preventing A1 receptors from being stimulated, causing venous and arteriolar dilation, lowering blood pressure. oral meds, given at bed time. ADRs include orthostatic hypotension, reflex tachycardia, headache, and dizziness. assess patient for orthostatic HTN and monitor HR. patient should report any ADRs, rise slowly, not drive within 12 hours of first dose, and report persistent headaches. not recommended for patients w/ history of hypertension or syncope or those with hepatic disease and geriatric clients.

metroprolol (beta blockers)

blocks beta 1 receptors in heart and kidney to reduce contractility, heart rate, renin release, vasoconstriction, fluid retention, and blood pressure. ADRs include bradycardia, low CO, rebound tachycardia and angina, and possibly heart failure. monitor HR and report if too low, also monitor for s/s of HF (SOB, edema, cough). discontinuing requires tapering. patient should check pulse daily, not stop abruptly, report new onset chest pain, and s/s of HF. not recommended for those with bradycardia, HF, PVD or Raynaud’s. use caution with asthma, COPD, and diabetes.

clonidine (alpha 2 agonist)

exhibits antihypertensive effects by activating A2 receptors in the brainstem to reduce sympathetic stimulation of the heart (inhibit effects of norepinephrine) and lower blood pressure. ADRs include CNS effects like drowsiness and dizziness, xerostomia (dry mouth) and rebound hypertension. monitor for CNS effects and taper client off if discontinuing. should be taken at bedtime. client should avoid other CNS blockers. not recommended for those on anticoagulant therapy, severe cardiac or cerebrovascular or renal disease.

carvedilol (alpha/beta blocker)

blocks both alpha and beta receptors in the heart, arterioles, and kidneys. this causes dilation of the arterioles, reduced HR and contractility, and decreased release of renin, leading to lower resistance and CO and an increase in excretion of Na and water. ADRs include dizziness and hypotension, bradycardia, and exacerbation of asthma. monitor vitals and report if low; check apical pulse for full minute before admin; hold if HR is below 60. client should report any ADRs, transition slowly between positions, avoid hazardous activities, and know how to take their own pulse. teratogenic. not recommended for those with severe HF, asthma or other bronchospastic disorders, diabetes, renal disorders, hepatic disorders, or those with PVD.

hydralazine (direct acting vasodilator)

dilates arterioles, lowers resistance, and reduces arterial pressure, all lowering BP. ADRs include reflex tachycardia, dizziness, weakness, fatigue, and headache. may cause s/s of SLE/lupus such as facial rash, joint pain, fever, nephritis, and pericarditis. monitor patient for tachycardia, hypotension, and edema and crackles in lungs. requires tapering for discontinuation. client should report any ADRs, change positions slowly, and not stop abruptly. not recommended for those with renal or hepatic impairment or those with cerebro/cardiovascular disease.

hydrochlorothiazide (thiazide diuretic)

blocks reabsorption of Na⁺ and Cl^-, promoting excretion of both along with water. increases urine output and potassium excretion. adequate kidney perfusion and GFR are needed for this medication to work. acts on DCT. ADRs include hypokalemia, dehydration, hypochloremia, hyponatremia, hyperglycemia, and hyperuricemia. monitor patients electrolytes and s/s of imbalances, dysrhythmias, and glucose in diabetics. client should increase potassium intake, take last dose well before bedtime, and report s/s of electrolyte imbalance. not recommended for those with anuria, preexisting electrolyte imbalances, and those with renal or hepatic impairment. teratogenic.

furosemide (loop diuretic)

blocks Na⁺ and Cl^- reabsorption, increases excretion of both with water, and increases urine output with potassium excretion. very potent; acts on ascending limb of loop of henle. ADRs include hypokalemia, dehydration, hypocholremia, hyponatremia, hypotension, ototoxicity, and hyperglycemia. monitor patient for electrolyte imbalances and s/s, blood pressure, dysrhythmias, and report tinnitus or vertigo. client should eat foods rich in potassium, take well before bedtime, and report any ADRs. not recommended for those with anuria, preexisting electrolyte imbalances, and those with renal or hepatic impairment. teratogenic.

spironolactone (K⁺ sparing diuretic)

blocks aldosterone, increasing Na and water excretion and K⁺ retention. urine output is small. acts on DCT and collecting duct. ADRs include hyperkalemia, menstrual irregularities, abnormalities in hair growth for women, gynecomastia (increase in breast gland tissue) in men, and impotence (ED) in men as well. monitor K levels and report if high. monitor blood pressure, dysrhythmias, and endocrine effects as well. client should report any ADRs and avoid K⁺ supplements and foods, as well as salt subs. not recommended for renal insufficiency, preexisting hyperkalemia, hepatic dysfunction, or diabetes. teratogenic.