Direct-Acting Alpha Agonists/Selective Beta-2 agonist (N-13) Flashcards
why does a reflex bradycardia occur with administration of Neo
baroreceptor stimulation
what is the onset and duration of neo
onset- immediate
duration 5-20 min
other than blood pressure stimulation what is neo used for
prevent nosebleeds during nasal intubation
reduce bleeding during ear, nose, and throat surgery
mydriatic in ophthalmology
where is vasopressin produced and stored?
hypothalamus posterior pituitary
what does vasopressin control
osmoregulation
vasopressin is a potent vasoconstrictor BUT it selectively dilates these threee things
renal afferents
pulmonary and cerebral arterioles
MOA of milrinone
PDE 3 inhibitiros- preventing the breakdown of cAMP,
how does milrinone improve left ventricular function
acceleration of calcium uptake by the sarcoplasmic reticulum.
how is milrinone used during high risk patients from cardiopulmonary bypass
improves weaning from bypass
if milrinone is given to a patient that is beta blocked or has beta receptor down regulation- does milrinone still work
YES- these drugs retain their inotropic effect even in the presence of beta-blocking agents or during B receptor down regulation. -as seen with HF patients-
PDE3 inhibitors may be used to augment the effect of direct acting b agonist such as
dobutamine or dopamine.
PD5 inhibitors include
viagra, revatio
when do we cautiously administer milrinone
renal failure patients- potential for life threatening arrhythmias as the drug is eliminated by the kidenys
ephedrine stimulates alpha and beta receptors how
indirectly and directly
ephedrine onset and duration
onset immediate
duration 15-1.5hr
administration forms of ephedrine
oral, intramuscular, subcutaneous
according to nagelhout- newer data is questioning the use of ephedrine in OB- why?
ephedrine produces increases in fetal metabolic rate, leading to fetal acidosis due to B stimulation and phenylephrine does not
subsequent dosing of ephedrine can produce
tachyphylaxis
selective beta 2 agonist have increased duration of action due to
their non catecholamine structure - they are resistant to COMT metabolism.
two puffs of salmeterol prevent what
exercise induced asthma
chronic use of selective beta 2 agonist can result in “this” from down regulation
tachyphylaxis
clonidine is used as part of catecholamine suppression test in the diagnosis of
pheochromocytoma
which receptors does clonidine work on
peripheral presynaptic alpha2
central alpha 2 receptors
