Adrenergic Neuron Blockers Flashcards
alkaloid from roots of Rauwolfia
reserpine
This drug blocks vesicle storage of amines by IRREVERSIBLY BLOCKING VMAT (vesicular membrane-associate transporter), depleting NE, DA, 5-HT
Reserpine
Primarily used for hypertension during pregnancy
methyldopa
ANB that can cause reduction in renal vascular resistance
methyldopa
False neurotransmitter (Methyldopa metabolite)
a-methylnorepinephrine
Methyldopa’s metabolite acts as an agonist on what receptor
alpha 2.
Methyldopa inhibits what enzyme?
DOPA decarboxylase
decreases dopamine –> decreased NE/E –> lower BP and cause central effects
Common A/E of methyldopa:
sedation
ANB that can cause positive Coombs Test
methyldopa
can cause immune hemolytic reaction
ANB that may cause or exacerbate ulcers
reserpine
ANB that requires NET, uptake 1
guanethidine needs to be transported across the membrane by NET, uptake 1
Sexual dysfunction, orthostatic hypotension are common side effects of
guanethidine
VMAT mechanism:
transports NE, DA, 5-HT from synapse into presynaptic vesicles
Uses NET 1 to accumulate in nerve ending, binding to vesicles and ultimately inhibiting NE release
guanethidine
ANB with Tyramine-like effect when given IV
guanethidine
CVS effect of guanethidine
Decreased BP (triple response)
MAO inhibitors interaction with Tyramine intake?
Hypertensive crisis
MAOIs prevent metabolism of tyramine –> increased tyramine levels –> release of stored catecholmines –> excess alpha and beta stimulation
ANB that interferes with catecholamine synthesis
methyltyrosine
Uses for methyltyrosine
pheochromocytoma (lowers catecholamine levels)
What drugs decrease effects of alpha 2 agonists like methyldopa
TCA inhibits NE reuptake, increase NE levels
alpha 2 agonists lower NE levels
ANB that causes depression
Reserpine
Highly associated with causing breast carcinoma
Reserpine
Quinone intermediate
6-hydroxydopamine
No clinical uses –> neurotoxic at nerve terminals causing chemical sympathetctomy
6-hydroxydopamine