Week 9: Ch. 13-16 ANS [Cholinergic & Adrenergic Agonists & Antagonists] Flashcards
Cholinergic receptors located throughout peripheral
nervous system
– At ___________ junctions in parasympathetic
division
– At _________ in both parasympathetic and sympathetic
divisions
– At neuroeffector junctions in parasympathetic
division
– At ganglia in both parasympathetic and sympathetic
divisions
Cholinergic receptors located in somatic nervous system
– At ___________ _________
neuromuscular junctions
- Cholinergic agonists (aka Parasympathomimetics)
– Drugs that increase action of ______________________, promoting rest-and-digest responses
– Drugs that increase action of ACh at cholinergic
receptors, promoting rest-and-digest responses
- Cholinergic agonists (aka Parasympathomimetics)
– Primary types : [2]
▪Muscarinic agonist
▪Nicotinic agonist
- Direct cholinergic agonists
– Produce _____________ responses
– Activate cholinergic synapses by releasing ACh into the synaptic cleft
– Drug binds to ACh receptors, enhancing _______________
– Drug inactivated by AChE
– Produce rest-and-digest responses
– Activate cholinergic synapses by releasing ACh into the synaptic cleft
– Drug binds to ACh receptors, enhancing action potential
– Drug inactivated by AChE
- Indirect-acting drugs
– Inhibit acetylcholinesterase _________ (cholinesterase)
– Neurotransmitter accumulates and remains in synaptic cleft for ________2_________
(AChE)
2- longer time.
▪Physiologically it does not matter whether cholinergic synapse activated directly or indirectly.
▪Parasympathetic responses:
the same.
- Indirect-acting cholinergic agonists – Acetylcholinesterase (AChE) inhibitors
▪_____________and affect ACh synapses located at autonomic ganglia, muscarinic receptors neuromuscular junctions, and ACh synapses in the
CNS
Nonselective
- Indirect-acting cholinergic agonists – Acetylcholinesterase (AChE) inhibitors
Medications
▪Increase __________ in GI, urinary tracts
▪Some can _______ intraocular pressure
Medications
▪Increase peristalsis in GI, urinary tracts
▪Some can decrease intraocular pressure
____________ ________
– Can be caused by overdose of medications, toxic gases, or insecticides
– Causes intense miosis, nausea, vomiting, urinary incontinence, increased exocrine secretions, abdominal cramping, and diarrhea
– Can also cause tachycardia, hyperglycemia, muscle weakness, flaccid paralysis
– Treated with atropine or pralidoxime to reverse muscarinic effects
- Cholinergic crisis
- Myasthenia gravis
– Literally “__________________ weakness”
– Considered a _________ disease
– Causes muscle weakness, difficulty in chewing, swallowing, speech, and vision
– Literally “grave muscular weakness”
– Considered a progressive disease
– Causes muscle weakness, difficulty in chewing,
swallowing, speech, and vision
- Myasthenic crisis
– May occur if patient with MG abruptly ___________________
– Extreme muscular weakness and symptoms similar to ____________
– Rapid, correct diagnosis essential
– May occur if patient with MG abruptly discontinues medication
– Extreme muscular weakness and symptoms similar to cholinergic crisis
– Rapid, correct diagnosis essential
Nicotinic Agonists
* Nicotine only drug used widely to activate:
ganglionic receptors
Nicotinic Agonists
Used primarily in nicotine replacement therapy (NRT) for ______________________
– Goal to gradually reduce patient’s _______________________
Used primarily in nicotine replacement therapy (NRT) for tobacco cessation
– Goal to gradually reduce patient’s physical dependence on nicotine
- Cholinergic antagonists
– Inhibit the action of ACh at _________________
– Drug action dependent on site of action
– Two types
??
??
– Inhibit the action of ACh at cholinergic synapses
– Drug action dependent on site of action
– Two types
▪Muscarinic
▪Nicotinic
Muscarinic antagonists
– Primarily block receptors in _______________________
– May also be known as anticholinergics, cholinergic blockers, muscarinic antagonists, or parasympatholytics
– Work by competing with ____ for binding at muscarinic receptors, allowing sympathetic activation to predominate
– Primarily block receptors in parasympathetic nervous system
– May also be known as anticholinergics, cholinergic blockers, muscarinic antagonists, or parasympatholytics
– Work by competing with ACh for binding at muscarinic receptors, allowing sympathetic activation to predominate
Nicotinic Antagonists: Ganglionic Blockers
- Interrupt transmission of nerve impulses at _______________
- Nonselectively inhibit ______
- Affect parasympathetic system more than sympathetic
- Work to lower blood pressure in emergency situations
- ___________ is only therapeutic use.
- Only one ganglionic blocker, mecamylamine (Vecamyl), is approved for use.
- Interrupt transmission of nerve impulses at nicotinic receptors
- Nonselectively inhibit ANS
- Affect parasympathetic system more than sympathetic
- Work to lower blood pressure in emergency situations
- Vasodilation is only therapeutic use.
- Only one ganglionic blocker, mecamylamine (Vecamyl), is approved for use.
Adrenergic Agonists
- Induce _________________ response
– May be therapeutic or adverse depending on
patient’s condition - Two receptor types
??
?? - Wider therapeutic applications due to lower incidence of adverse effects
- Induce fight-or-flight response
– May be therapeutic or adverse depending on
patient’s condition - Two receptor types
– Alpha
– Beta - Wider therapeutic applications due to lower incidence of adverse effects
- Catecholamines
– _______ duration of action
– Destroyed rapidly by monoamine oxidase (MAO) and COMT
– Cannot be given __________
– Must be given parenterally or by inhalation
– Do not cross _____________ barrier
– Short duration of action
– Destroyed rapidly by monoamine oxidase (MAO) and COMT
– Cannot be given orally (PO)
– Must be given parenterally or by inhalation
– Do not cross blood-brain barrier
- Noncatecholamines
– May be taken _____________
– Not destroyed as readily by MAO or COMT
– Better able to enter ________ and affect CNS
– May be taken orally (PO)
– Not destroyed as readily by MAO or COMT
– Better able to enter brain and affect CNS
Alpha-Adrenergic Agonists
* Used to treat ____________ associated with shock
* Treatment of patient susceptible to orthostatic hypotension
* Treatment of nasal congestion
* Topical instillation of alpha1 agonists to eye
– Examining interior structures
– Relieving conjunctival congestion, redness
- Used to treat hypotension associated with shock
- Treatment of patient susceptible to orthostatic hypotension
- Treatment of nasal congestion
- Topical instillation of alpha1 agonists to eye
– Examining interior structures
– Relieving conjunctival congestion, redness
