Adrenergic Drugs, Etc. Flashcards
Alpha agonists and their receptors
Phenylephrine - a1
Clonidine - a2
Mixed alpha and beta agonists and their receptors
Epi - a1, a2, b1, b2
NE - a1, a2, b1
Beta agonists and their receptors
Dobutamine - b1
Isoproterenol - b1, b2
Albuterol - b2
MOA of cocaine
Inhibit re-uptake of NE and DA
MOA of Selegine and Phenelzine
Inhibit MAO
MOA of amphetamine, methylphenidate and tyramine
Increase release of NE and DA
Non-selective alpha (a1 and a2) receptor antagonists
Phentolamine
Phenoxybenzamine
Selective a1 receptor antagonists
Prazosin
Tamsulosin
Doxazosin
Mixed blockers and their receptors
Labetalol - b-, a1
Carvedilol - b-, a1
b1 and b2 blockers
Propanolol
Pindolol
Nadolol
b1 selective blockers
Metoprolol
Betaxolol
Acebutolol
Atenolol
Phentolamine
Phenoxybenzamine
Non-selective alpha (a1 and a2) receptor antagonists
Prazosin
Tamsulosin
Doxazosin
Selective a1 receptor antagonists
Labetalol
Carvedilol
Mixed blockers and their receptors
Propanolol
Pindolol
Nadolol
b1 and b2 blockers
Metoprolol
Betaxolol
Acebutolol
Atenolol
b1 selective blockers
NE release inhibitor
Guanethidine
Inhibitor of tyrosine hydroxylase
Metyrosine
Phenylephrine
Mydriatic and decongestant
Causes severe VC, increased BP, severe bradycardia
+a1
Clonidine causes:
A decrease SNS outflow, lower BP and bradycardia
What happens locally when clonidine is applied?
VC.
How does clonidine decrease BP when it binds to an a2?
It is selective to a2 neurons in the brainstem and causes inhibition of NE release, which lowers BP and causes bradycardia.
Isoproterenol
+ inotropic and chronotropic effect (b1)
VD (b2)
Bronchodilation (b2)
What drug has unique activity at a1 receptors?
What is unique?
Dobutamine.
(-) isomer is an a1 agonist, while (+) isomer is an antagonist
Dobutamine
Positive inotropic effect
DA
VD (D1)
Suppression of NE release (D2)
At high doses, it activates b1 in heart.
At even higher doses, it activates vascular a1 and causes VC.
What are the kinetics of phentolamine?
Reversible competitive alpha antagonist.
Shorter-acting.
What are the kinetics of phenoxybenzamine?
Non-competitive alpha antagonist.
Long-acting.
Beta-blockers’ effect on:
- Heart
- BVs
- RAAS
- Respiratory system
- Eye
- Metabolism
Heart: neg. inotropy/chronotropy, slow AV conduction.
BVs: initially, rise in PVR. Chronically, decrease in PVR.
RAAS: inhibit renin release.
Respiratory system: increased airway resistance.
Eye: dec. aqueous humor production and intraocular pressure.
Metabolism: inhibit lipolysis, increase LDL, inhibit sugar breakdown in liver.
