-
Adrenergic receptor inactivation
- reuptake
- enzymatic inactivation
- -monoamine oxidase (MAO) - found inside of presynaptic neuron
- - catechol-omethyl-transferase (COMT) - located on postsynaptic neuron
- diffusion
-
Direct-acting receptor agonist
acts directly on receptors
-
Indirect-acting receptor agonist
stimulates norepinephrine release or blocks norepinephrine reuptake
-
Norephinephrine
- direct-acting receptor agonist
- non-selective
- alpha 1, beta 1
-
Ephinephrine
- direct-acting receptor agonist
- non-selective
- alpha 1; vasoconstriction; increases blood pressure; dilated pupils
- beta 1; tachycardia
- beta 2; bronchodilation
-
Dopamine
- direct-acting receptor agonist
- non-selective
- alpha 1, beta 1, D1-D5
- D1 and D2 (peripheral dopamine receptors); renal, coronary, mesenteric and cerebral arteries
- function; vasodilation, increased blood flow, glomerular filtration rate, sodium excretion, catecholamine release
-
Amphetamine
- indirect-acting
- promotes norephinephrine release and blocks norepinephrine reuptake
-
Cocaine
- indirect-acting
- blocks norephinephrine reuptake
-
Ephedrine
- mixed-acting (has direct and indirect effects)
- activates receptor and promotes norephinephrine release
- nonselective
- alpha 1, beta 1, beta 2
-
alpha-adrenergic receptor antagonists
- Doxazosin - selective, alpha 1
- Phentolamine - non-selective, alpha
-
Uses for alpha-adrenergic receptor antagonists
- benign prostatic hypertrophy
- hypertension
- peripheral vascular disease
-
Side effects of alpha-adrenergic receptor antagonists
- orthostatic hypertension
- dizziness
- reflex tachycardia
-
beta-adrenergic receptor antagonists
- Metoprolol, Atenolol - selective beta 1
- Propranolol, Nadolol - nonselective beta 1 and beta 2
- Carvedilol, Labetalol - mixed alpha 1, beta 1 and beta 2
-
Uses of beta-adrenergic receptor antagonists
- decrease heart rate and arterial blood pressure
- treat angina, congestive heart failure, tremor, pheochromocytoma, anxiety, migraine
- contraindicated in COPD or asthma
|
|
