Adrenergic Drugs Affecting ANS Flashcards
Main neurotransmitter of sympathetic nervous system (sns)
Mainly norepinephrine (NE) -post ganglionic
Also epinephrine (adrenaline)
Catecholamines moa
Bind to same target tissues as epinephrine
Natural-NE,Epi, dopamine
Synthetic- isoproterenol and dobutamine
Adrenergic transmission
Alpha 1,2
Beta 1,2,3
*activation of each receptor subtype=characteristic response
What breaks down NE?
COMT (catechol-O-methyltransferase) in synapse
MAO (monoamine oxidase) in cell
Epinephrine vs Norepinephrine transmission
NE>synapse>alpha or beta receptor on target tissue
Epi goes directly into circulation but also works on receptors just like NE
-restart heart
What breaks down Epi?
Liver
Approaches to affecting adrenergic neuronal transmission
- synthesis of neurotransmitter in termalinal
- prevent storage of neurotransmitters in presynaptic nerve
- prevent release of neuros in presynap
- prevent destruction or reuptake of neurotransmitters
- bind to receptor on postsynaptic target tissue
Alpha 1
NE>Epi (affinity)
Located on All sympathetic target organs besides heart
Tx:nasal congestion,hypotension
*Constriction of blood vessels and dilation of pupils
Alpha 2
NE=Epi
Located on presynaptic nerve terminals
Tx:hypertension
*inhibit release of NE through feedback inhibition
Beta 1
NE>Epi
Located on heart and kidneys
Tx:shock, heart failure, cardiac arrest
*Increased HR and force of contraction
Beta 2
Epi>NE
Located on all sympathetic target organs
Tx: asthma, premature labor
*smooth muscle relaxation/inc metabolism
Beta 3
NE=Epi
Located on adipose tissue/urinary bladder
Tx:overactive bladder
*inc adipose tissue lipolysis/relax detrusor muscle (bladder)
Dopamine receptors
Located in arterioles,kidneys, and heart
Low doses-vasodilation through kidneys
High doses- alpha 1 and beta 1 agonism
Adrenergic Drugs:agonists
Epinephrine (adrenalin) Isoproternol (isuprel) Pseudoephedrine (sudafed) Phenylephrine (neo-synephrine) Albuterol (ventolin) Monoamine oxidase inhibitors(MAOI)
Epinephrine(adrenalin) moa
Alpha and beta (+) which stimulates sns
Tx:cardiac arrest, asthama, allergic react.
Isoproternol(isuprel) Moa
Beta 1 and 2 (+) which inc heart rate, smooth muscle relaxation(bronchodilation)
Tx:asthma, dsrhythmias, heart failure
Pseudoephedrine(sudafed) moa
Alpha 1 and beta 2 (+) constrict blood vessels in nose
Tx: nasal decongestant
Phenylephrine(neo-synephrine) moa
Alpha 1 (+)
Also used for nasal decongestant and acute hypotension
*can be used for vascular shock
Albuterol (ventolin) moa
B(+) relaxation of smooth muscle(bronchodilation)
Tx:asthma, copd
Monoamine oxidase inhibitors(MAOI) moa
Inhibit enzyme that breaks down catecholamines to inc NE
Tx:used in hypertensive crisis
Alpha 1 antagonists
Autonomic drugs for heart
Prazosine(minipress)
Prazosine (MiniPress) Moa
Alpha 1 (-) which causes vasodilation to dec blood pressure
Beta Blockers (antagonists) Moa/tx
Dec HR, dec force of contraction, and dec AV node conduction
Tx: hypertension, angina pectoris, migraines, dysthymias
*can mask hypoglycemia in diabetics
Beta blocker drugs
Atenolol(tenormin)
Metaprolol (lopressor, toprol)
Carteolol (cartol)
Atenolol(tenormin) Moa
Beta 1 (-)
Cardiac selective
Metaprolol (lopressor, toprol) Moa
Beta 1 (-)
Carteolol (cartol)
Beta 1 and 2 (-)
You can go cold turkey off Beta Blockers T/F
False
