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67 Cards in this Set
- Front
- Back
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rate limiting step in acetylcholine syntehsis? what drug blocks this?
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uptake of (+) charged choline molecule with active - cotransport of Na
blocked by hemicholinium |
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steps of ACh synthesis following uptake and drugs that block each
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1. uptake of choline with Na cotransport = blocked by hemicholinium
2. choline + acetyl CoA is catalyzed by choline acetyltransferase and blocked by vesamicol 3. Ach taken up into vesicles with ATP 4. AP by voltage gated Na channel opening reaches the presynaptic terminal...induces voltage gated ca channels to open in the presynaptic neuron and vesicles fuse with the pre synaptic membrane release of ACH = inhibited by botulinum toxin 5. ACH released in the terminal binds with muscarinic or cholinergic ACH 6. AChesterase cleaves acetylcholine into choline and acetate and process restarts |
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black widow spider toxin
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causes all ACH to be released from presynaptic vesicles
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generalized anticholinergic stimulation SE
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DUMBBELSS
diarrhea urination miosis (constriction) bronchospasm bradycardia (M2) excitation of skeletal muscle and CNS lacrimation sweating salivation also...ab cramping |
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used for postoperative, postartum urinary retention and neurogenic ileus
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bethanechol
resistanct to ACHE direct cholinomimetic/cholinergic/ ACH agonist |
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direct cholinergic agonist used to tx glaucoma
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carbachol
pupillary contraction induced releases intraocular pressure no SE |
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first line treatment for acute/emergency cases of glaucoma when it is necessary to rapidly lower intraocular pressure and drain aqueous humor
type of drug? SE? |
pilocarpine
direct cholinergic agonist major side effecgts = PILE on the sweat and tears = secretogogue |
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this drug is a direct muscarine receptor agonist used in challenge test for diagnosis of asthma by causing bronchoconstriction
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methacholine
inhaled |
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indirect cholinergic agonist that crosses the BBB and can be used with overdose of atropine, pehnothiazines, TCAs
mech? |
physostigmine
can tx glaucoma although pilocarpine is #1 can tx overdose of rx who have anticholinergic action mech = anti-acetylcholinesterase (enzyme that degrades ACH in the synaptic cleft) = increases endogenous ACH can be used to combat central acting anti-Muscarinic agents such as atropine |
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major difference in neostigmine vs pyridostigmine
which is choice for anesthesiologists to use for reversal of neuromuscular blockade? do they cross the BBB? tx usage of each? mech? |
neo = short acting
pyrido = long acting neo = choice neither crosses the BBB neo = postop and neurogenic ileus, urinary retention, acute MG, reversal of NMJ block Pyrido = MG long acting mech = anti-acetylcholinesterase |
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overdose of edrophonium is tx with?
mech of edrophonium and primary use? |
atropine (anitcholinergic) + praladoxime (early admin - regenerates ACHesterase)
mech = anti-acetylcholinesterase use = short acting (minutes) and used in dx of MG -- admin IV and if muscle strength dramatically imporves, test is + for MG |
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symptoms of cholinesterase inhibitor poisoning? common occurrences with whom?
antidote? |
DUMBBELSS
Diarrhea urination miosis = contracted pupil Bronchospasm Bradycardia Lacrimation Sweating Salivation common with gardners (insectisides), caused by parathion, organophosphates (covalently bind to ACHesterase - think echothiophate and military nerve gases) antidote = atropine (muscarine antagonist) + pralodoxime (chemical antag used to regen active cholesterase) |
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muscarine antagonist used to produce mydriasis and cycloplegia?
effects on eye, airway, stomach, gut, bladder? CI? |
atropine
eye = pupil dilation, blurry near vision (cycloplegia) airway = decreases secretions stomach = decr acid secretion gut = decreased motility bladder = decreased urgency with cycstitis CI = glaucoma pt, men with prostatic hyperplasia (avoid urinary retention), ileus + GI obstruction, infants with fever (hyperthermia), delerium pts, elderly (can cause open angle glaucoma), |
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the following are sx relating to what type of toxicity?
hyperthermia, rapid pulse, dry mouth, dry flushed skin, cycloplegia, constipation, dilireum/disorientation |
atropine toxicity
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nicotinic agonist used to prevent reflex bradycardia caused by NE?
mech? SE? |
hexamenthonium
blocks choline uptake by presynaptic neuron - but since it acts on nicotinic receptors, acts on both symp and para, so effect determined by tissue dominance: BP dominated by symp -- opposed -- thus lower BP other dominated by parasymp usually -- thus decreased urine output decreased GI motility pupul mydriasis (dilated) increased HR severe orthostatic hyotension, blurred vision, consitpation, sexual dysfunciton |
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muscarine antag used to tx asthma and COPD (increases FEV)
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ipratropium
tx of asthma in pt who can't take adrenergic agonists |
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choice medication for motion sickness? mech? other uses?
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scopolamine = patch behind ear
mech = muscarine antag other uses = end of life care to reduce N and V; decreases secretions for coughers |
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mech and use for benztropine
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parkinsons
muscarin antagonist |
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muscarine antagonist used to tx PUD
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methcopolamine and propantheline (decreases salivatroin, decreases gut motility, decreases stomach acid)
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muscarine antagonist that reduces urgency in mild cystits and reduce bladder spasm
other uses? |
oxygutynin
glycopyrrolate (also used in anesthesia to decrease airway secretions along with atropine) |
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low dose Epi selects for ____ receptors? immed effect?
high dose epi? CI with _____ b/c it causes arrythmia major uses? |
low dose = B receptors = think vasodilation
high dose = a receptors = think constriction CI = digoxin uses = all Type I hypersensitivity rx (histamine induced anaphylaxis), open angle gluacoma, asthma, hypotension, cardiac arrest |
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direct sympathomimmetic used for septic shock?
receptors it stimulates and overall affect? |
NE
a1 a2 > B1 increases systolic, diastolic and mean arterial pressure with no affect on pulse pressure tx of hypotension, but decreases renal perfusion |
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reflex bradycardia caused by NE can be counteracted by using this agent prior to NE admin
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atropine
muscarine antagonists - blocks vagal response reflex bradycardia due to vasoconstriction and weak B2 |
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used in heart failure and cardiogenic shock - avoid with a-fib
name drug and give receptors |
dobutamine
B1>B2 increases CO without increase in HR increases AV conduction so don't use with A-fib |
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catecholamine used to tx shock - increases renal perfusion
where is it found endogenously? high doses induce what response? |
dopamine
basal ganglia high doses induce a1 vasoconstriciton D1=D2 >B>a |
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catecholamine responsible for a widened pulse pressure and elevated HR
change to glc levels in blood? |
epinephrine
B2 = vasodilation of liver, skeletal mucle, increased glycogenolysis in liver a1 = htn due to constrcition of skin, mucous membrane, viscera B1 = increased contractility and hr to increase CO a2 = lower insulin glucose increases - CI with DM pt |
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catecholamine isolated to B receptors? use?
affect on MAP, systolic press, diastolic press, and HR? |
isoproterenol
no a only B1=B2 use = AV block via increased CO decreases MAP, systolic and diastolic increases HR dramatically b/c of reflex tachy with lowered BP (relative to Epi and NE) |
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selective B2 agonist used for bronchodilation, and elevated HR and contractility
which is used for actue asthma? premature uterine contraction? long term asthma tx? admin subq for asthma? |
metaprotenol, albuterol, salmeterol, terbutaline
B2>B1 acute asthma = albuterol, metaproterenol long term = salmetorol (usually with CSC) uterine contraction and subq asthma =terbutaline NOTE = ritodrine is strictly B2 acting and used to reduce premature uterine contractions |
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catecholamine reuptake inhibitor used as a local anesthetic in nasal surgery
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cocaine
causes vasoconstriction |
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catecholamine that induces released of stored catecholamines used for narcolepsy, ADD, and obesity - sometimes used to bridge gap for elderly pt starting TCAs or SSRIs
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amphetamine
CI with PG |
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sympathomimmetic used for nasal decongestoin
other uses of each |
ephedrine - urinary incontinence, hypotension
psuedoephedrine - less CNS side effects than ephedrine phenylephrine - epistaxis (only a receptors here), SVTs |
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sympathomimmetics with reflex bradycardia
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NE (a2, a1>B1)
phenylephrine (a1>a2) |
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receptor responsible for renin release? opposing action?
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B1
decrease renin with a1 |
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potassium uptake
glycogenolysis vasodilation of skeletal muscle vasculature receptor? |
B2
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increased lipolysis?
decreased? |
B2
a2 |
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a2 agonist that is used to tx htn and also used for pt with addiction to benzos and opiates for withdrawal
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clonidine
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difference between catecholamines and noncatecholamines
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catecholamines = rapid onseet, brief action duraiton, not orally - only IV, do not penetrate BBB
includes epi, ne, iso, dopamine, dobutamine, phenylephrine, clonidine, metaproterenol non = longer duration of action, can be admin orally includes, albuterol, terbutaline, salmeterol, amphetamine, ephedrine, pseudoephedrine |
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centrally acting a2 agonist used to tx hypertension in PG pts or with renal dz b/c it does not decrease blood flow to the kidney
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clonidine
a-methyldopa (can be used in PG patients) decreases release of NE form presynaptic neuron -- decresae in sympathetic outflow caution = rebound htn -- clonidine is short acting, must be dosed regularly, if you miss a dose, you get rebound htn |
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a1 receptor effects
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vasoconstriciton (skin, mucous membrane, abdomen, kidney) -->increased bp causes decrease in renin release
increases TPR, sphincter tone pupil dilation = mydriasis increases sphincter tone decreases mucosal secretion due to constriciton (decongestants here are agonists) |
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a2 receptor effects
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decrease ACh and NE release from CNS presynaptic neurons
decreases insulin release from the pancreas decreases lipolysis |
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B1 receptor effects
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increased automaticity
increased conduction velocity (avoid with afib) increased contractility increases renin release |
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B2 receptor effects
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smooth muscle vasodilation - skel muscle, liver, etc.
bronchodilation (asthma, COPD) increased insulin release increased lgucose metabolism and lipolysis increased K+ uptake, increased glycogenolysis GB releaxes, bladder relaxes GI motility slows utuerus relaxes |
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a and B receptor sensitivity to epi, ne, and iso
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a = epi >/= NE >> ISO
B = ISO > EPI > NE |
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used with pts prior to removal of pheochromocytoma or if pt needs chronic management of diffuse catecholamine secreting tumors
drug? mech? SE? reversible form of this drug? |
phenoxybenzamine
nonselective a-antagonist irreversible so overcomes the effect of catechol during operative tumor removal -- catechol levels can spike here and cause htn crisis SE = orthostatic (postural) hypotension (everything is dilated) or reflex tachy phentolamine |
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commonly associated with first dose orthostatic hypotension/syncope
which is given with diuretics for htn? which is given for BPH to increase urinary outflow? common SE? |
a1 selective antagonists
prazosin, terazosin, doxazosin, tamsulosin prazosin + diuretic b/c it tends to retain water and salt tamsulosin for bph SE = dizziness (low bp), HA (vasodilation) |
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elderly pt that is depressed, not eating or sleeping would benefit most from this presynaptic regulator
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mitrazapine (remeron)
a2 selective antagonist |
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all clinically available B blockers are ________ antagonists
this means that they increase/decrease EC50 of the agonist? |
competitive
increase (decreased potency) |
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postural hypotension usually occurs due antagonism of what receptors?
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a1
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sympathetic drugs that are contraindicated in pts with COPD, asthma? why?
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B blockers - selective and unselective
they block B2 induced bronchodilation |
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why is it important to use a diuretic with B blockers?
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decreased blood pressure due to decreased CO -- decreases renal perfusion and induces Na and water retention via RAA system
decreased renin production by blockage of B1 = also contributes to low CO relflex hypertension will cause Na and H20 retention |
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why is there concern with using B blockers with diabetics?
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danger of hypoglycemia when given insulin
blockade leads to decreased glycogenolysis and decreased glucagon secretion |
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drug of choice for treatment of glaucoma chronic dz
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timolol = nonselective B blocker -- no change in pupil size or change in near vision/accomodatoin
drug of choice for acute atatck = pilocarpine |
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used for prophylactic migraine tx to decrease incidence or severity of attack - give rx and mech
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propanolol
nonselective B antagonist |
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treats the widespread sympathetic simtulation that occurs with hyperthyroidism (thyroid storm) -- prevents cardiac arrythmia
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propanolol
arrythmias not helped are ventricular arrythmias not caused by exercise |
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using a B blocker for tx of angina is common. is it used ofr acute or chronic management? why?
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chronic management
decreases contractility of the heart and heart rate -- work is decreased thus O2 consumption decreases |
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which B blockers are known for decreasing mortality (sudden death due to arrythmia) in relation to an MI?
mech? |
metoprolol (B1>B2) = B1 selective antagonist
carvedilol (non-selective a and B atangonist) |
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what are the nonselective B antagonists
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propanolol
nadolol timolol - glaucoma pindolol carvedilol - a1 too labetalol - a1 too |
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B blockers used to tx pts with HTN put with impaired pulmonary function (asthma COPD)
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B1 selective antagonists
acebutolol betaxolol esmolol atenolol metoprolol B2 responsible for bronchodilation |
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which partial B agonists act as B blockers? how?
use? |
acebutolol and pindolol
partial agonists stimulate receptor, but prevent stimulation by more potent endogenous catecholamines -- diminished affect on CO and HR compared to other B blockers use these with pts having HTN and experiencing bradycardia or with diabetics |
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use this a/B antagonist to tx elderly or black hypertensive indivis where increased TPR is undesirable? SE?
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labetolol
SE = orthostatic htn, dizziness (think a1 antag) |
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B blockers used to tx pts with HTN, DM, and are on insulin or hypoglycemic drugs
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B1 selective antagonists
acebutolol betaxolol esmolol atenolol metoprolol B2 has influence on carb metabolism |
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used with PG hypertensives as an alternative to a-methyldopa
receptors? |
labetelol
a1, B1, B2 antagonist |
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used to tx SVTs? mech?
if you are concerned about slowing heart rate (as with CHF or 1st degree heart block) which should you use? |
propanolol (nonselective B antag), esmolol (short acting B1 selective)
esmolol = IV admin - short acting -- can be withdrawn quickly |
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B blocker + cocaine = ?
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hypertensive crisis
Cocaine = unopposed a1 vasoconstriction B blocker = antagonizes B2 vasodilation == all constricted causes really high BP |
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decreases bp for pt in aortic dissection - choice rx
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B blockers
initial rise in BP is what rips the aorta, not the overall BP level -- B blockers temper the rise in pressure |
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rx decreases recurrence of bleeding with esophageal varices? mech?
this class of drugs is used to tx htn in chronic liver dz? |
esoph varices -- think portal htn -- think nadolol = long acting nonselective B antagonist
B blcokers |
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common SE of B blockers
common SE of A blockers |
B = fatigue and exercise intolerance
A = orthostatic htn, and reflex tachy |
