Section 5a: Sympathomimetics Flashcards
What is the advantage of using an alpha-1 agonist over a cholinergic antagonist for mydriasis?
No cycloplegia (alpha-1 won’t change the shape of the lens (M3 ciliary muscle))
At low doses this drug which induces renal, mesenteric, and coronary vasodilation.
Dopamine
Epinephrine receptors
alpha 1 and 2, beta 1 and 2
Norepinephrine receptors
alpha 1 and 2, beta 1
Isoproterenol receptors
beta 1 and 2
Beta 1 selective drug used in short-term management of severe refractory CHF
Dobutamine
centrally-acting alpha 2 agonist used as 3rd line anti-hypotensive
Clonidine
Which sympathomimetic would you use to treat a hypotensive patient with sepsis? Low, med or high dose?
Dopamine. Low dose stimulates renal vasodilation and furthermore, Na secretion (diuresis). Med dose + inotropic wo/ chronotropism. Not up to high-dose since this stimulates alpha 1…vasoconstriction.
Used for severe hypotensive states
Norepinephrine
For AV block, cardiac arrest, and anesthesia related bronchospasm
Isoproterenol.
Treatment of shock especially if accompanied with low cardiac output and compromised renal function
Dopamine
Preferred vasopressor for treatment of septic shock
Norepinephrine
Not orally effective, short duration of action, do not cross BBB.
Catecholamines.
What is the class of orally effective, long duration, BBB crossing sympathmimtic drugs? Which ones are they?
Non-catecholamines. No catechol group. Phenylephrine, Clonidine, Terbutline.
alpha 1 agonist produces marked vasocontriction
Phenylephrine
