sympatholytic agents

Question 1

Drugs that interfere with NE release or deplete NE

Answer 1

Guanethidine
guanadrel
Bretylium
Reserpine*

Question 2

centrally acting a2 agonist drug list

Answer 2

Clonidine*
methyldopa*
guanfacine

Question 3

Guanethedine

Answer 3

interferes with ne release
uptake I, Displacement and release of NE, Blocks NE release
highly charge
treats htn uncontrolled by other meds
se orthostatic htn

Question 4

guanadrel

Answer 4

more rapid onset, shorter duration and less se compared to guanethidine

Question 5

Bretylium

Answer 5

Antiarrhythmic
mechanism -blocks NE release
prolongs ventricular action potential and refractory period
prophylaxis & treatment of V-fib, 2ndline agent

Question 6

Reserpine

Answer 6

depletes ne by blocking vesicular transporter
decreases co (last choice antihypertensive)

Question 7

Clonidine

Answer 7

An a2-adrenergic receptor agonist
IV-increase BP (peripheral a2) followed by decreased BP (central a2)
Oral -decreased BP (decreased C.O., preload)
Patch -same as oral
Clinical Use
Essential hypertension (very little use now)
adjunct for narcotic withdrawal
other off-label uses
Side Effects
dry mouth, sedation, impotence
sudden withdrawal causes hypertensive crisis

Question 8

Methyldopa

Answer 8

False neurotransmitter concept
Converted to methyl-NE
stored in vesicles instead of NE
released & acts as a centrally acting a2-agonist
compare with clonidine
Considered a drug of choice for treating hypertension in pregnant females

Question 9

Guanbenz and Guanfacine

Answer 9

Central a2-adrenergic receptor agonists
like clonidine but less used
Also used to treat tics or Tourette’s syndrome
Sometimes used for behavioral symptoms, such as impulse control disorders.