Adrenergic drugs Flashcards
Alpha 1 type AR G protein and effect
Gq, Increase IP3 and DAG
Alpha 2 type AR G protein and effect
Gi, decrease cAMP
Beta 1, 2, 3 type AR G protein and effect
Gs, increase cAMP
Dopamine 1-5 AR G protein and effect
1 and 5 Gs increase cAMP
2-4 Gi decrease cAMP
Alpha 1 physical effects: Vascular smooth muscle Pupillary dilator muscle Prostate Heart
Contraction
Contraction (mydriasis/dilation)
Contraction
Increases force of contraction
Alpha 2 physical effects: Postsynaptic CNS neurons Platelets Adrenergic and cholinergic nerve terminals Some vascular smooth muscle Fat cells
Probably multiple Aggregation Inhibits NT release Contraction Inhibits lipolysis
Beta 1 physical effects:
Heart, juxtaglomerular cells
Increases force and rate of contraction; increases renin release
Beta 2 physical effects:
Respiratory, uterine and vascular smooth muscle
Skeletal muscle
Human liver
Promotes smooth muscle relaxation
Promotes potassium uptake, increase contractility
Activates glycogenolysis and gluconeogenesis
Beta 3 physical effects:
Bladder
Fat cells
Relaxes detrusor muscle
Activates lipolysis
Direct Alpha agonist drugs
Phenylephrine
Clonidine
Direct mixed alpha and beta agonists
NE and Epi
Direct beta agonist drugs
Dobutamine, isoproterenol, albuterol
Direct dopamine agonist drugs
Dopamine
Epinephrine What receptors does it act on? Effect on cardiac function Effect on vasculature Effect on respiratory system Other effects
Acts on Alpha 1 and 2, Beta 1 and 2 agonist
Increases force of contraction, HR and conduction velocity
Increases systolic BP, but decreases diastolic and TPR, MAP often remains unchanged; cutaneous vessel contraction; skeletal muscle vasculature dilation
Relaxes bronchial muscle, decreases secretion and congestion
Causes muscle tremor, increases K uptake by skeletal muscle, elevates blood glucose levels, increases free fatty levels in blood, increases renin release
Norepinephrine Receptors? Effects on heart? Effects on vasculature Effects on lungs
Alpha 1 and 2, beta 1 agonist
Cardiac stimulant, but reduces heart rate
Vasoconstrictor
No bronchodilation
Increases peripheral vascular resistance and BP
Phenylephrine Receptors? Effect on eye Effect on lung Vasculature Heart
Alpha 1 agonist Mydriatic Decongestant Severe vasoconstriction, BP elevation Severe bradycardia
Clonidine Receptors Effects? Local application produces? MOA
Selective alpha 2 agonist
Targets brainstem to decrease sympathetic outflow, reduces BP and bradycardia
Vasoconstriction
Regulates NE release by presynaptic alpha 2 adrenoceptors
Isoproterenol
Receptors
Effects
Beta 1 and 2 agonist
Increase HR, strength of contraction, CO, vasodilator, decrease arterial pressure, causes bronchodilation
Dobutamine
Receptors
Effects
Beta 1 agonist, alpha 1 receptor activity
Potent inotropic action
Less prominent chronotropic effect compared to isoproterenol
Albuterol
Receptors
Effect
B2 agonist
causes bronchodilation and relaxation of uterus
Dopamine
Receptors
Effect
D1 and 2 agonist
Causes vasodilation in renal, cerebral, mesenteric and coronary vessels
Suppresses NE release
Activates B1 in heart at higher doses
At even higher doses, stims alpha 1 receptors in vasculature to cause vasoconstriction
Cocaine MOA and effect
Inhibits re uptake of DA and NE
Local anesthetic properties, peripheral and intense central action
Phenelzine/selegiline MOA and effect
Inhibits MAO
Increases NE stores in CNS, antidepressant
Amphetamines/methylphenidate MOA and effect
Inhibits reuptake of DA and NE, increases their release, may have weak direct effect
Stimulant on mood and alertness, decreases appetite
