Sympathetic drugs Flashcards
Other than being taken back up into the presynaptic neuron, some NE can be broken down by _____________
Monoamine oxidase (MAO) and catechol-O-methyltransferase
An example of drug action on the synthesis of NE
Methyldopa acts as a ‘false transmitter’ that reduces NE production and creates a different metabolite that causes sympathetic inhibition.
An example of drug action on the storage of NE
Resperine blocks the uptake into storage vesicles of NE so when the stored up NE runs out there is no more left to be used.
An example of drug action on the release of NE
Bretylium blocks the release of NE at the synapse decreeing the amount available.
An example of drug action on the uptake/reuptake of NE
Imipramine inhibits reuptake of NE causing it to remain in the synapse longer.
Beta 1 agonists are often used to treat _________
Cardiac disease
Epinephrine in general is used to treat _________
Anaphylactic reactions
Beta 2 agonists are often used to treat _________
Obstructive airway disease
Alpha 2 agonists are often used for _________
Sedation/analgesia
Beta 1 antagonists are often used to treat _________
tachyarrhythmias
Alpha 1 antagonists are often used to treat _________
vasodilation (?)
Alpha 2 antagonists are often used as _________
reversals for Alpha 2 sedation
What are catecholamines?
endogenous substances that serve as hormones/neurotransmitters
**positive ionotropes (contractility)
What are 5 examples of catecholamines?
Epinephrine Norepinephrine Isoproterenol Dopamine Dobutamine
What receptors are targeted by epinephrine and what is it used for?
All adrenergic receptors. Alpha 1 - vasoconstriction Alpha 2 Beta 1 - cardiac contraction (cardiac arrest) Beta 2 - bronchodilation (anaphylaxis) Beta 3 -
Epinephrine mode of delivery?
IV, IM, SC.
NOT given orally because it is rapidly metabolized by the GI tract.
T/F Catecholamines generally cross the BBB
FALSE.
Catecholamines generally do not cross the BBB
When to be cautious using epinephrine?
Glaucoma, non-anaphylactic shock, combined with other drugs effecting the heart, Tachycardia/tachyarrhythmias.
What type of drug is epinephrine?
Catacholamine - Direct acting sympathomimetic
Norepinephrine mode of delivery?
Given intravenously.
What receptors are targeted by norepinephrine?
Mainly alpha receptors but also beta 1.
NOT beta 2.
What is norepinephrine used for?
It will increase mean arterial blood pressure, increase after load of the heart, and be a potent vasoconstrictor due to lack of beta 2 involvement.
Cautions for using norepinephrine?
Combined with other drugs effecting the heart, and avoid extravasation (injecting outside of the blood vessel could cause tissue damage).
What type of drug is norepinephrine?
Catacholamine - Direct acting sympathomimetic