Adrenergic Drugs Flashcards
Alpha-1 pathway
Gq - PLC, IP3/DAG, Ca++/CaM, PKC, Ras, Raf, Mek, Erk
Beta/gamma subunit activity in Gq
PI-3 kinase, AKT
Alpha-2 pathway
Gi - Adenylyl cyclase inhibition, less cAMP, less PKA
Beta pathway
Gs - Adenylyl cyclase, cAMP, PKA (catalytic subunits)
Vascular smooth muscle
Alpha-1: Vasoconstriction
Beta-2: Vasodilation
Pupil
Alpha-1
Dilation
Hair
Alpha-1
Erects hair
Prostate
Alpha-1
Contraction
Heart
Alpha-1: Contraction
Beta-1: Contraction
Adrenergic and cholinergic nerve terminals (pre-synaptic)
Alpha-2: Inhibits transmitter release (auto-regulation)
Fat cells
Alpha-2: Inhibits lipid release
Beta-3: Activates lipid release
Smooth muscle (respiratory, uterine)
Beta-2: relaxation
Skeletal muscle
Beta-2: Potassium uptake
Liver
Beta-2: Glycogenolysis (activate glucose release)
Bladder
Beta-3: Relax detrusor
Renal blood vessels
D1: Dilation
Nerve endings
D2: Modulates transmitter release
Direct-acting adrenergic drug clases
Agonsts, antagonists
Indirect-acting adrenergic drug function
Altering NE at receptor location
Cocaine
Indirect agonist
Re-uptake inhibitor for DA and NE
Selegiline, Phenelzine
Indirect agonist
MAO inhibitors
Ephedrine
Mixed-acting agonist
NE release + receptor agonist
Amphetamines, Methylphenidate (Ritalin)
Indirect agonist
Reverse NE and DA uptake, increased release
Alpha direct agonist drugs
Phenylephrine
Methoxamine
Clonidine
Mixed alpha/beta direct agonist drugs
NE, Epinephrine
Beta direct agonist drugs
Dobutamine
Isoproterenol
Terbutaline
Albuterol
Dopamine direct agonist drugs
Dopamine
Fenoldopam
Alpha-1 > alpha-2 direct agonists
Phenylephrine
Methoxamine
Alpha-2 > alpha-1 direct agonists
Clonidine, methylnorepinephrine
NE vs Epinephrine
NE = Both alpha's, Beta-1 Epi = Both alpha's, both beta's
Beta-1 > beta-2 direct agonist
Dobutamine
Beta-2 > beta-1 direct agonists
Albuterol, terbutaline, ritodrine
Isoproterenol
Both beta’s equal
Fenoldopam
D1
Overall effect of an adrendergic drug is based on what things?
- Receptors expressed at a tissue
- Receptor selectivity of drug
- Intrinsic activity of drug
- Compensatory reflexes
- Tolerance and tachyphylaxis development
Tachyphylaxis
Sudden decrease in response to drug after administration