Adrenergics Flashcards
Alpha 1 agonism
vasoconstriction, possible reflex bradycardia (due to PANS action independent of drug agonist)
Alpha 1 agonist drugs
phenylephrine, methoxamine, oxymethazoline, tetrahydrozoline
Main uses for Alpha 1 agonists
cold medication, phenylephrine can be used for shock along with methoxamine (has SE of vagal reflex)
Alpha 2 agonism
causes decrease in sympathetic outflow from nerve terminals
Alpha 2 agonist uses
mainly for HTN
Alpha 2 agonist drugs
clonidine, dexmedetomidine, guanabenz, guanfacine, methyldopa
Beta 1 agonism
increase HR, increase contractility, inc. SV, inc. CO
Beta 2 agonism
Vasodilate (lower BP),
Isoproterenol MOA
act on beta 1 and beta 2
Isoproterenol uses
Tx for bronchospasm (thru B2 action), heart block (due to B1 action), bradyarrhytmias (due to B1 action)
Isoproterenol SE
flushing, angina, arrythmias
Dobutamine MOA
B1 more than B2 action
Dobutamine uses
CHF
Selective B2 agonists
Salmeterol, Albuterol, Terbutaline
Salmetrol uses
prophylaxis to asthma attack due to slow action
Albuterol, Terbutaline use
immediate use for asthma
B2 selectives SE
palpitations due to the vasodilation
way to distinguish Nor-epi from Epi
nor-epi does not affect B2 (therefore can NEVER lower BP) while epi does, also EPI is released from the adrenals
Dosing changes in receptors with Epi
low dose: B1, B2 action
medium dose: B1, B2, A1
High dose: B1, B2, more predominant A1 action w/ reflex bradycardia chance increasing
Alpha antagonist actions
low total peri. resistance, lower mean BP
selective alpha 1 blockers
OSIN enders, prazosin, doxazosin, terazosin, tamsulosin
non selective alpha blockers
phentolamine (competitive), phenoxybenzamine (non-competitive)
selective alpha 2 blockers
yohimbine, mirtazapine
major SE from alpha blockade
possible reflex tachy, and renin-angiotensin activation (to inc. BP)
which class are used in pheochromocytoma?
non-selective alpha blockers, phenoxybenzamine is the DOC
selective alpha 1 blocker uses
BPH (only relaxes trigone to help bladder empty), HTN
Mirtazipine other uses
depression and helps stim lbs gain
B1 blockade effects
dec. HR, dec SV, dec. CO, decrease renin release, dec. aqueous humor production
B2 blockade effects
precipitate bronchospasm in asthmatics, vasospasm in pt with vasospastic disorders, metabolic effects (decrease gluconeogenesis and glycogenolysis) can result in hypoglycemia, can mask hypoglycemia episode due to stopping the hypoglycemia indced tachycardia
names A-M means?
B1 selective
olol means?
beta blocker of some kind
beta blockers that increase blood lipids
atenolol, metoprolol, propranolol, timolol
beta 1 selective makes drug safer for…
asthmatics, diabetics, people with peri vascular diseases
beta blockers with intrinsic sympathomimetic activity..
acebutolol (agonist slight to B1), pindolol (agonist slightly to B1, B2)
what does intrinsic sympathomimetic mean
act as partial agonist to other receptors, allowing for less bradycardia (thru B1), slight vaso or broncho dilation (thru B2), minimal change in plasma lipids (thru B2)
which beta blockers don’t have increase lipids associated with it
acebutolol, pindolol
which beta blockers are sedative
ALL except atenolol; Propranolol is most sedative
general uses of beta blockers
angina, HTN, post-MI
Antiarrhymatics: propranolol, acebutolol, esmolol
Glaucoma: timolol
Migraine, thyrotoxicosis, performance anxiety, essential tremor—Propranolol
drugs with alpha 1 and beta blocker activity
labetalol, carvedilol; use in CHF
K channel block and Beta blocking activity
Sotalol (class III antiarrhymatic)
