NR 293 Exam 3 Study Guide

NR 293 Exam 3 Study Guide • Alpha2-adrenergic receptor stimulators (agonists)/clonidine o Stimulate alpha2-adrenergic receptors in the brain o Decrease sympathetic outflow from the CNS, decrease norepinephrine production o Stimulates alpha2-adrenergi receptors, thus reducing renin o Examples: Clonidine (Catapres), Methyldopa (aldomet): used for pregnant women w/htn • Alpha1-blockers/”azosin,” o Block alpha1-adrenergic receptors o Management of severe heart failure (HF) when used with cardiac glycosides and diuretics o Some used to relieve symptoms of BPH- increase urinary flow rate o Example: “ Azosin” (doxazosin (Cardura) o Adverse Effects: ▪ Serious: hypotension (first dose) syncope ▪ Common: dizziness o Nursing implications: instruct pt. to lie down after taking first dose because they may become dizzy • Beta-blockers “olol”: First-line treatment for heart failure & HTN o Reduce BP by reducing heart rate through beta1 blockade (block receptors for norepinhrine) o Cause reduced secretion of renin o Long-term use causes reduced peripheral vascular resistance o Adverse Effects: orthostatic hypotension, bradycardia w/ reflex tachycardia, sexual dysfunction in men, possible hypoglycemia or hyperglycemia • Angiotensin-converting enzyme inhibitor, “pril” Captopril o Mechanism of Action: ▪ Inhibit angiotensin-converting enzyme, which is responsible for converting angiotensin I (through the action of renin) to angiotensin II ▪ Angiotensin II is a potent vasoconstrictor and causes aldosterone secretion from the adrenal glands ▪ Result in decreased systemic vascular resistance (afterload), vasodilation, and therefore decreased blood pressure o Indications: ▪ First-line treatment for heart failure & HTN ▪ HF (either alone or in combination with diuretics or other drugs) ▪ Slow progression of left ventricular hypertrophy after MI (cardio protective) ▪ Renal protective effects in patients with diabetes ▪ Captopril and lisinopril can be used if a patient has liver dysfunction, unlike other ACE inhibitors that are pro-drugs • *Pro-drugs are inactive in their administered form and must be metabolized in the liver to an active form so as to be effective o Adverse Effects: hyperkalemia & dry, nonproductive cough o Serious drug interaction: NSAIDs • Angiotensin II receptor blocker “sartan” losartan (Dovan) o Mechanism of Action: ▪ Allow angiotensin I to be converted to angiotensin II, but block the receptors that receive angiotensin II ▪ Block vasoconstriction and release of aldosterone ▪ Well tolerated, do not cause a dry cough ▪ Indications: first-line treatment for heart failure & HTN o Adverse Effects: URI, headache ▪ May cause occasional dizziness, inability to sleep, diarrhea • Calcium channel blockers: Amlodipine “dipine” verapamil (calan), diltiazem (cardizem) o Mechanism of Action: cause smooth muscle relaxation by blocking the binding of calcium to its receptors, preventing muscle contraction o Adverse effect: constipation ▪ High-fiber diet with plenty of fluids will help prevent constipation o Indications: hypertension ▪ Angina- ch. 23 • Ischemia: o Ischemic heart disease: Poor blood supply to the heart muscle (Atherosclerosis, Coronary artery disease) o Myocardial infarction (MI): Necrosis, or death, of cardiac tissue, disabling or fatal • Therapeutic Objectives o Minimize the frequency of attacks and decrease the duration and intensity of anginal pain o Improve the patient’s functional capacity o Prevent or delay the worst possible outcome: MI • Cardiac glycosides: Digoxin o Therapeutic level: between 0.5-2ng/mL o Digoxin doses are held and the prescriber notified if the apical pulse is 60 beats/minute o Negative chronotropic effect decreases HR o Digoxin immune Fab (Digifab) is the antidote for a severe digoxin overdose ▪ Required use of digitab when potassium level is above 5 mEq/L, severe sinus bradycardia that does not respond to cardiac pacing, or an overdose of more than 10 mg of digoxin. o Avoid bran muffins when taking digoxin o Hypokalemia increases the chance of digitalis toxicity • Class III drugs: Amiodarone (ch. 25) o Mechanism of action: prolonging action potential duration o Indications: ventricular dysrhythmias o Contraindication: hypersensitivity and bradycardia or AV block Adverse effects: FDA black box warning: pulmonary toxicity, hepatotoxicity arrhythmia worsening-sinus bradycardia, constipation, QT prolongation, hypotension, blue-gray coloring of the skin on the face, arms, and neck • Unclassified antidysrhythmics: Adenosine (Ch. 25) ▪ Slows conduction through the AV node ▪ Used to convert paroxysmal supraventricular tachycardia to sinus rhythm ▪ Very short half-life (less than 10 seconds) • Flush with 20cc of normal saline ▪ Only administered as fast IV push ▪ May cause asystole for a few seconds ▪ Adverse Effects • ALL antidysrhythmics can cause dysrhythmias! • Hypersensitivity reactions, nausea, vomiting, diarrhea, dizziness, blurred vision, headache ▪ Assessment • Obtain a thorough drug and medical history • Baseline BP, P, I&O, and cardiac rhythm • Measure serum potassium levels before initiating therapy • Conditions that may be contraindications for use of specific drugs • Potential drug interactions ▪ During therapy, • Monitor cardiac rhythm, heart rate, BP, general well-being, skin color, temperature, heart and lung sounds • Assess plasma drug levels as indicated • Monitor for toxic effects • Take medications as scheduled and not to skip doses or double up for missed doses • Contact their physician for instructions if a dose is missed • Notify health care provider of any worsening of dysrhythmia or toxic effects • Nitrates and nitrites: Nitroglycerin o Prototypical nitrate o Large first-pass effect with oral forms o Used for symptomatic treatment of ischemic heart conditions (angina) o IV form used for BP control in perioperative hypertension, treatment of HF, ischemic pain, pulmonary edema associated with acute MI, and hypertensive emergencies o Adverse effects: headaches ▪ Reflex tachycardia ▪ Postural hypotension ▪ Tolerance may develop o Tolerance ▪ Occurs in patients taking nitrates around the clock or with long-acting forms ▪ Prevent tolerance by removing patch at bedtime for 8 hours, then apply a new patch in the morning o Nitroglycerin ▪ Nursing implications: • If the chest pain is not relieved after one tablet, call 911 immediately. • Never to chew or swallow the sublingual form • Non-polyvinylchloride (non-PVC) plastic intravenous bags and tubing must be used when giving IV nitroglycerin • Burning sensation felt with sublingual forms indicates that the drug is still potent • Proper application of nitrate ointments and transdermal forms, including site rotation and removal of old medication before new dose is applied. • Instruct patients to take PRN nitrates at the first hint of anginal pain ▪ Antidysrhythmia patient implications: • Do not chew or crush ER meds • If GI distress occurs take the drug with food • Limit or avoid the use of caffeine