indirect sympathomimetics

Question 1

how are catecholamines synthetized and transported ?

Answer 1

-Tyrosine(“pulling Tire towards dock”) →enter nerve terminal (“dock”) →L-dopa(“L-shaped rope handle”) → dopamine(“wheel saying dope rope”) →enter vesicle(“sea vessel) →converted to NE by Dop-β-hydroxylase
(“North compass scout standing on sea vessel”)

• catecholamines enters snyaptic vesicles at nerve terminal through VMAT (“V-mat”)
• once the catecholamines(“catfish”) (NE, dopmaine) are released into synapse they re-enter nerve terminal through NET NorEpinephrine Transporter

(“hauled catfish in NET”)

Question 2

name the indirect sympathomimetics

Answer 2

Metyrosine
(camp counsler Mitch yelling “My Tire”)

Cocaine
(“Hot Cocoa”)

Atomoxetine
(“atom next to empty net”)

Reserpine /tetrabenazine
(“serpent on Vmat”)

Amphetamines
(“a friend of mine releasing catfish”)

Methylphenidate
(“friend date show on HDTV”)

Modafinil
(sleeping scout hitting “sleep mode” clock)

Question 3

Metyrosine
(sympatholytic)

(“camp counsler Mitch holding tire”)

Answer 3

• Tyrosine analog that inhibits the synthesis of L-DOPA from tyrosine and therefore catecholamine synthesis
• antihypertensive

(camp counsler Mitch holding tire and shouting “it’s MY TIRE !! “)

Question 4

Cocaine

(“Hot Cocoa”)

Answer 4

-peripherally inhibits NET leading to sympathetic stimulation that includes :

• hypertension
• ​tachycardia
• ​mydriasis
• ​agitation

​​(“stimulated scouts drinking hot cocoa ignoring catfish net”)

-centrally inhibits DAT thus leading to increased dopamine concentration in CNS causing

• arousal
• ​addiction
• ​seizures

-bloody nose due to nasal mucosa atrophy / septal perforation due to vasoconstriction effect
(“hot cocoa scout girl bleeding from nose”)

-can cause coronary vasospasm and eventually MI

(“constricted red crown on hot cocoa mug ,constricted red tethers on anvil connected to catfish net “)

• can cause Angina
  (“constricted net on anvil”)

-during cocaine intoxication, adminstration of β-blockers may cause severe hypertension due to unopposed α1 stimulation

(“hot cocoa scout putting his hand inside Bugle creating high pressure”)

Question 5

Atomoxetine

(“Atom next to empty net”)

Answer 5

-NET inhibitor useful in treatment of ADHD
(“scout distracted from catfish NET because he’s watching HDTV”)

Question 6

Reserpin/Tetrabenazine

(“Serpent snake”)

Answer 6

-inhibits VMAT transporter(“snakes sitting on v-mat”) found on synaptic vesicles and through which catecholamines enter the vesicle ,

-exhibits dose related depression due to depletion of catecholamines

(“scout kid next to the snake looks depressed AF!!!”)

Question 7

Amphetamine

(kid on sea vessel wearing “A-friend of mine” shirt “)

Methylphenidate
(kid watching “friend date” on HDTV)

Answer 7

-displaces catecholamines into synapse
(kid wearing “A-friend of mine” shirt dumping catfish into water” )

-Methylphenidate is an Amphetamine derivatives that is useful for treatment of ADHD
(“kid distracted by “friend date “ show on HDTV)

-Stimulants including Amphetamines ,Methylphenidate, and Modafinil are known to decrease appeptite

(“note the untouched dinner next to kid watching friend date”)

Question 8

Modafinil

(sleeping scout hitting “sleep mode” on clock)

Answer 8

-useful in treatment of **Narcolepsy

-**
MOA for sleep disorders uknown , acts as A-typical selective dopamine reuptake inhibitor

Question 9

what are the dopamine receptors? what effects do they exert ?

Answer 9

“Dope Rope SWING”
-D1R G(s) coupled , D2R G(i) coupled
​——————————————————————————–
D1 (“single rope swing”)

• at low doses D1 receptors stimulation
  increases RBF,GFR, Na+ excretion
  (“low kidney tied to single rope”)
• ​at medium doses dopamine stimulated β1 receptors inducing cardiac activation
  (“β bugler hanging in the middle of the rope”)
• ​at high doses dopamine stimulates α1 receptors inducing pressor effects
  (“α scout camp kid holding a single lit candle hanging on the top of the rope”)

**that’s why it can be use as a pressor for treatment of heart failure/shock in case NE treatment failed**
​——————————————————————————–
D2 (“Double rope swing”)

-G(i) coupled

-found in the CNS
(“scout kid on swing wearing brain helmet”)