Adrenergic antagonists : Adrenergic neuron blockers Flashcards
Reserpine guanethidine Guanadrel
sympatholytics are:
adrenergic antagonist
define adrenergic neuron blockers
drugs that disrupt the synthesis, storage, or release of norepinephrine
Guanethidine
Guanadrel
Act by:
Inhibit norepinephrine release and deplete neuronal amine stores
Guanethidine
Guanadrel are
Orally active compounds used to treat
severe hypertension (limited use)
which neuron blocker, guanethidine or Guanadrel, is a polar compound – does not enter the CNS
Guanethidine
Guanethidine and Guanadrel are short/long acting
long acting
How do guanethidine and guanadrel get into adrenergic nerves?
Via NE transporter NET
What drugs may compete with guanethidine and guanadrel? (also inhibit NET)
tricyclic antidepressants
Guanethidine and guanadrel have numerous side effects such as:
orthostatic hypotension,
interferes with sexual function,
diarrhea, muscle weakness, edema
This drug Diffuses into adrenergic nerves – transport does not require the NET
Reserpine
How does Reserpine work?
Depletes nerves of neurotransmitters – by inhibiting the vesicular monoamine transporter 2 (VMAT2) responsible for sequestering dopamine into storage vesicles
vesicular monoamine transporter 2 (VMAT2) responsible for
sequestering dopamine into storage vesicles
Reserpine is orally active and used to tx:
essential hypertension in combination with other drugs – rarely used
Reserpine enters this system and causes side effects
d. Long-acting, slow onset
e. Side effects – Sedation, diarrhea, orthostatic hypotension, increased gastric acid secretion
Enters CNS and has CNS side effects. May cause depression, suicide (suicidal tendencies), and sedation
This adrenergic neuron blocker can cause depression, suicide (suicidal tendencies), and sedation
Reserpine
