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Pharm test 3
Pharm adrenergic blocking agents ch.18
Question | Answer |
---|---|
Adrenergic blockers **adrenergic antagonists **sympatholytics | bind to adrenergic receptors, but inhibit or block stimulation of the sympathetic nervous system (SNS) **alpha blockers and beta blockers |
alpha blockers | -cause both arterial & venous dilation, reducing peripheral vascular resistance & BP -used to treat HTN -effect on receptors on prostate gland & bladder decreased resistance to urinary outflow, thus reducing urinary obstruction & relieving effects of B |
alpha blockers | -alpha blocker like pills are used to treat HTN b/c it dilates -alpha is resp. for sphincter control so ppl with problems going to the bathroom take an alpha blocker (especially men over 60 w/ enlarged prostate -- BPH (benign prostate hypertrophy) |
alpha blockers used to control & prevent HTN in patients with pheochromocytoma | pheochromocytoma: tumor in adrenal gland. ppl w/ this have malignant HTN b/c they constantly secrete things coming form adrenal cortex (NE, EPI, adrenaline) |
alpha blockers: phentolamine -quickly reverses the potent vasoconstrictive effects of extravasated vasopressors such as norepinephrine or epinephrine **restores blood flow & prevents tissue necrosis | phentolamine: lets say I gave you too much epi in IV & it infiltrated, your blood vessels start constricting in arm so you have less blood supply to that area & that tissue can die **you can shoot in phentolamine subq causing vasodilation to save your ar |
alpha blockers side effects | CV: palpitations, orthostatic hypotension, tachycardia, edema, dysrythmias, chest pain CNS: drowsiness, dizziness, headache, anxiety, depression, vertigo, weakness, numbness, fatigue |
alpha blockers side effects | GI: nausea, vomiting, diarrhea, constipation, abdominal pain OTHER: incontinence, nosebleed, tinnitus, dry mouth, pharyngitis, rhinitis |
Common alpha blocker agents | -phentolamine (regitine): used to dilate if given a vasopressin -prazosin (minipress) -tolazoline (priscoline) |
It is common to see the first dose faint effect when receiving alpha blocker agents | First does faint effect: ppl. will get out of bed & faint b/c they re pretty powerful BP meds (can cause orthostatic hypotension) |
what do alpha blockers usually end in? | -zosin **they are pretty powerful in lowering BP |
beta blockers | -block stimulation of beta-receptors in the SNS -compete with norepinephrine and epinephrine -selective & non selective also called cardio selective & non specific |
beta blockers | they are very popular; they lower BP no b/c of vasodilation (if you block beta1 the HR will slow down & so cardiac output is going to decrease which decreases the BP) |
Cardio selective and nonspecific | cardioselective: selective b/c it only blocks beta1 in the heart nonspecific: blocks both beta 1 and 2 and it is nonselective |
beta 2 blocker **beta 2 receptors primarily on smooth mucles of bronchioles & blood vessels | if you block beta 2 it will constrict the bronchioles which would be a problem for asthma-- so in someone w/ asthma you would give them a cardioselective blocker so that you dont make asthma worse by constricting their bronchioles |
non specific beta blockers **block both beta 1 and 2 | -Propranolol (inderal) -labetalol (trandate, normodyne) |
what do beta blockers end in? | beta blockers end in -lol |
cardioselective beta adrenergics | -acebutolol (sectral) -atenolol (tenormin) -metoprolol (lopressor) |
mechanism of action for cardioselective | -slows down conduction rate -reduces SNS stimulation of the heart -decreases HR -prolongs SA node recovery -slows conduction through AV node -decreases myocardial contractility, thus decreasing myocardial oxygen demand |
mechanism of action for cardioselective | -patients with angina have chest pain b/c of need for O2 in the heart so you would give a beta blocker to reduce contractility which decreases oxygen demand in the heart |
mechanism of action for nonspecific (beta1 & beta2) | effects on heart: same as cardioselective bronchioles: constriction, resulting in narrowing of the airways & SOB blood vessels: vasoconstriction |
Indications for beta blockers | antiangina: decreases demand for myocardial oxygen cardioprotectve: inhibits stimulation from circulating catecholamines **studies have shown that if you had a heart attack & are given a beta blocker it prevents having a heart attack in the future |
indications for beta blockers | -antihypertensive -treatment of migraine headaches -glaucoma (topical use) |
side effects of beta blockers | -decreased force of contraction -decreased cardiac output -decreased BP -decreased HR -decreased automaticity of ectopic pacemakers -slowed conduction through AV node -less effective metabolism of glucose -less ability to respond to stress |
side effects of beta blockers | less ability to increase HR & cardiac output in response to exercise or activity **watch HR and hold drug if <60bpm (take pulse) |
common adverse effects of beta blockers | -bradycardia -congestive heart failure (CHF) -weakness, fatigue -bronchoconstriction **sometime you slow the HR so much that you get a weak heart (CHF) not pumping enough to perfuse major organs like kidney & brain so you start retaining fluid, BP |
adrenergic-blocking agents implications | -avoid OTC meds b/c they cause vasoconstriction and they can counteract -possible drug interactions with: antacids, antimuscarinics/anticholinergics, diuretics & CV drugs, neuromuscular blocking agents, oral hypoglycemic agents |
NURSING IMPLICATIONS for adrenergic-blocking agents | -teach patients to change positions slowly to prevent postural hypotension -avoid caffeine (excessive irritability) -avoid alcohol (can have a glass) |
therapeutic effects for adrenergic-blocking agents | -decreased chest pain in pt. with angina -return to normal BP and P |
NURSING IMPLICATIONS for beta-blocking agents | -rebound HTN or chest pain may occur if this medication is stopped abruptly -inform pt. that they may notice a decrease in tolerance for exercise; dizziness & fainting may occur with increased activity |
you should NEVER abruptly stop a beta-blocker **if you choose not to take drug you can damage kindey or have a heart attack | -sometimes men do b/c these drugs can cause erectile dysfuntction -the heart is pumping slowly & then you abruptly stop, this will cause the heart to start beating super fast & can cause heart attack |
when taking beta blockers pt. should report weight gain of more than 2 pounds within a week | -if you're gaining too much weight it is water weight and this can be indicative of congestive heart failure |
A 58 y/o male is taking propranolol (inderal) 40 mg TID for angina & cardiac dysrhythmias. During nursing assessment, the nurse records that the ct. state, "I am troubled at times with asthma." VS: BP 126/84 pulse 62 resp. 24 1.Prop. blocks wut receptor | blocks beta 1 and 2 which affects his asthma and decreases HR |
A 58 y/o male is taking propranolol (inderal) 40 mg TID for angina & cardiac dysrhythmias. During nursing assessment, the nurse records that the ct. state, "I am troubled at times with asthma 2. could propranolol affect asthma? | yes it does |
A 58 y/o male is taking propranolol (inderal) 40 mg TID for angina & cardiac dysrhythmias. During nursing assessment, the nurse records that the ct. state, "I am troubled at times with asthma 3. what effect could propranolol have on HR. why? | decrease HR |
A 58 y/o male is taking propranolol (inderal) 40 mg TID for angina & cardiac dysrhythmias. During nursing assessment, the nurse records that the ct. state, "I am troubled at times with asthma 4. what are the teaching aspects that should be explained? | do not abruptly stop, teach him how to take pulse & call doc if it is less than 50. |
A 58 y/o male is taking propranolol (inderal) 40 mg TID for angina & cardiac dysrhythmias. During nursing assessment, the nurse records that the ct. state, "I am troubled at times with asthma 5. what could happen if ct. abruptly stopped this drug? | if he abruptly stopped he can develop HTN & eventually have a heart attack |
when a patient has experienced infiltration of a peripheral infusion of dopamine, the nurse knows that injecting the alpha-blocker phentolamine (regitine) will result in local | vasodilation |
when administering beta-blockers, the nurse knows that which guideline for administration and monitoring is correct? | weaning off the medication is necessary to prevent rebound HTN |
The nurse providing teaching for a pt. who has a new perscription for beta1 blockers will keep in mind that these drugs may result in which effect? | bradycardia |
a patient who has recently had an MI has started therapy with a beta blocker. the nurse explains that the main purpose of the beta blocker is to | protect the heart from circulating catecholamines |
before initiating therapy with a nonselective beta blocker, the nurse should assess the patient for the presence of | asthma |
a patient is taking an alpha blocker as treatment for benign prostatic hypertrophy. the nurse monitors for which potential drug effects? | -orthostatic hypotension -increased urine flow -headaches |