ANS Drugs 4-2-15 Flashcards
T or F: Because the PNS extends through the body, these drugs can affect other body systems.
True. Example: a drug meant to ease uterine pain may also relieve leg pain.
Drugs that act at the synapse between nerves can adjust the transmission of neurotransmitters by?
- Increasing the amount of neurotransmitter within the vesicles
- Decreasing the amount of neurotransmitter within the vesicles
slide 18
What pharm class are Dopamine and Isoproterenol a part of? Cholinergic or adrengergic? Agonist or antagonist?
adrenergic agonist
Dopamine and Isoproternol are adrenergic agonists. Do they work on the sympathetic or parasympathetic system?
Sympathetic (remember that adrenergic agonists are also called SYMPATHomimetics)
The nervous system consists of the central nervous system and the __ __ ___.
peripheral nervous system
The peripheral nervous system consists of the _____ nervous system and the ______ nervous system
Autonomic Nervous System (automatic) and Somatic Nervous system (voluntary - like wave your arms)
What is the basic functional unit of the nervous system?
neuron
The autonomic nervous system is a division of the peripheral nervous system that regulates what?
individual organs and homeostasis, it is not under voluntary control. Also known as visceral system.
The sympathetic nervous system, which controls fight or flight, is said to be _______ and uses both ACh and NE for neurotransmission.
adrenergic
ACh is used in the preganglia; NE (norepinephrine) is used in the post.
The PARAsympathetic nervous system, which controls rest and digest, is said to be _______ and uses ______ in both the pre and post ganglia
cholinergic; acetylcholine
The neuron is composed of three parts. Name them:
- Cell body
- dendrite (branch type structure)
- axon (long projection that carries impulse AWAY)
What do neurons use to communicate?
neurotransmitters
What does a synapse structure consist of?
- presynaptic neuron
- postsynaptic neuron
- synaptic cleft (space between pre and post)
Explain how the neurotransmitter in the synapse functions
PPT explanation:
NT crosses the synaptic cleft to regenerate nerve impulse; this nervous impulse is carried to a neuroeffector junction, where an action potential is inititated.
Lamen’s Terms:
NT goes from from presynapse to post-synapse–> generates electricity –> post synapse sends to target organ –> dumps out the NT–> causes receptor site to react.
When NT is released one of two things happens:
- It is either “sucked up” by the neuron (post synaptic) and used or;
- terminate through _________
reuptake (and used again)
T or F: All PREganglia neurons in the SNS and the PSNS use Acetylcholine (Ach).
True.
In the PSNS, ACh is used in pre and post
In the SNS, ACh is use in the pre, but NE (norepinephrine) is used in the post.
Acetylcholine (ACh) is synthesized from ______
It is synthesized from Choline.
___________ is synthesized from Tyrosine.
Norepinephrine
In the SNS, receptors are either ______ or ______.
alpha
beta
What is the chain of sympathetic ganglia?
A chain of ganglia situated ventral and lateral to the spinal cord. Originates from the CNS. Leaves from chain to the SNS.
In the SNS, the preganglia connect to the _____ _____ _____ ____. The post ganglia branch out and from there to the target/key organs.
chain of sympathetic ganglia
Summary:
Adrenergic –> SNS, alpha 1 & 2, beta 1 & 2;
preganglia = drops on the target sites
Cholinergic –> PSNS; nicotinic = voluntary, muscarinic – involuntary; ACH in pre and post synapse and drops on target sites
Her final summary at the end of class.
Alpha 1 (SNS Receptor Site - Adrenergic) is on the blood vessels. If stimulated, it ______ the blood vessels.
constricts (IF STIMULATED! Blocked is a whole other story)
Examples:
For Nasal Congestion, constricts blood vessels and you can breath better. Also used to control topical/superficial bleeding.
Downside: can cause HTN due to constricted blood vessels.
Indications: BLOOD vessels so use alpha 1 agonist when in need of vasoconstriction (decongestant shrinks vessels in nose) – Neo-Synephrine (phenylephrine) <alpha specific
Antagonist = vasodilation; preventing constriction
Alpha 2 (SNS Receptor Site - Adrenergic) is located on the nerve membranes (nerve terminals). If stimulated, it decreases the amount of ______ released, causing a drop in blood pressure.
norepinephrine
How does it work? slows the heart, treats HTN
Other uses: used to treat glaucoma (pressure build up in eye);
Side effects: Burning sensation, ptosis
Beta 1 (SNS Receptor Site - Adrenergic) is located on the heart. If stimulated it beats ______.
Faster, IF STIMULATED!
increases HR and CO so it can be used to treat heart failure, cardiac arrest and shock (including anaphylactic shock).
Beta 2 (SNS Receptor Site - Adrenergic) is located on the lungs (blood vessels and bronchi). If stimulated, you breathe easier due to ________.
bronchodilation
(delay preterm labor)
side effetcs: hypoglycemia and tremors
Why is epinephrine given to a person in anaphylactic shock?
It stimulates Beta 1 & 2, allowing easier breathing and HR increase.
What do selective and non selective mean?
Selective - can trigger specifically beta 1 OR 2
Non Selective - triggers/effects beta 1 and 2
What are a couple of adverse effects of Beta 2 stimulation?
Hyperglycemia and Tremors
Example: When I have had asthma attacks and used a nebulizer, I shake really bad (tremors) and I feel dizzy from low blood sugar. I always need to sit for awhile after and usually have to drink apple juice.
_________ stimulates the release of NE from the nerve ending; increasing renal flow, cardiac output (CO) and elevated blood pressure.
Dopamine
With increased CO comes tachycardia
WIth elevated b/p comes paliptations
T or F: Drugs can be used to affect normal processes in the body but cannot give cells or neurons new functions.
True
They may:
- Synthesize NT in presynapse
- Store NT in presynapse
- Release NT in presynapse
- Bind receptor site of postsynapse
- Destroy the NT (ex. make more acetylcholinesterase, destroys ACh).
- Alter balance of NT (can cause the vesicles carrying NT to have an unusually large amount)
slide 18
T or F: Drugs are classified by the receptor that they stimulate or block.
True
- Adrenergic agonists (Sympathomimetics) in SNS
- Adrenergic blockers (Sympatholytics <Sympath = sympathetic ; lytic=lysis or destruction of a substance)
- Cholinergic agonist (Parasympathomimetics) in PSNS
- Anticholinergic (cholinergic blocker)
slide 19
Agonists _______; antagonists ________.
stimulate; block
If a person takes a sympathomimetic (adrenergic agonist) such as Dopamine or Isoproternol, it stimulates the _____ nervous system by acting on the ______ receptors. It causes the HR to go up.
If the person takes an adrenergic blocker it ______ the response.
SNS
adrenergic
prevents
(Don’t memorize dopamine or isoprotenerol according to Tong)
A cholinergic agonist stimulates the _______ nervous system.
PSNS
A parasympathetomimetic (cholinergic agonist) mimics the parasympathetic nervous system. They are divided into two subclasses _____ acting and ______ acting
direct (binds to the receptor site; blocks all other from binding) and indirect (gets ride of the enzyme that causes ACh to go away, allowing ACh to build at receptor site).
An indirect acting muscarinic agonist (also called __________), binds to cholinergic receptors and inhibit acetylcholinesterase which allow MORE ACh to build up at the receptor site.
parasympathomimetic
Will effect ALL ACh sites.
Cholinergic is PSNS; An agonists means to make more/to stimulate it; can stimulate in two ways:
1. Direct: Drug sits on receptor site and mimics the real deal; OR 2. Indirectly by letting natural ACh bulid up (by blocking ACh-ase) allowing the bodies ACh to work more efficiently.
________ block the effects of acetylcholine at muscarinic receptors. Use of them has declined due to their side effects.
anticholinergics (atropine)
• Acts by blocking ACh at muscarinic receptors
used to dry secretions, treat asthma (bronchodilator), and prevent motion sickness. Occasionally used to accelerate heart rate, dilate pupils, treat parkinson’s and IBS.
Do Alpha and Beta Adrenergic Agonists stimulate or block adrenergic receptors? What is a prototype for this group?
AGONIST stimulates!
dopamine (Inotropin)
An alpha-specific adrenergic agonist ______ only alpha receptors.
What is a prototype for this group?
stimulates
phenylephrine (Neo-Synephrine) - this is in respiratory , not necessary to remember
____ ______ adrenergic agonists stimulate only beta adrenergic receptor sites.
What is a prototype for this group?
beta specific
isoproterenol (Isuprel)
What is shock?
critical condition that is brought on by a sudden drop in blood flow through the body. The circulatory system fails to maintain adequate blood flow, sharply curtailing the delivery of oxygen and nutrients to vital organs. It also compromises the kidneys and so restricts the removal of wastes from the body
T or F: MAOIs interact with everything.
according to Tong true!
What are the adverse reactions to Alpha & Beta Adrenergic Agonists?
Hint: It’s a PHAAD!
UNDERLINED IN PPT: P alpitations H ypertension A rrhythmias A ngina D yspnea
also nausea/vomiting/headache/sweating
PICK UP HERE!
SLIDE 31
Alpha 1 or Alpha 2
ALpha 1 - BP is stimulated so it increases (constricts blood vessels and stimulated nerve membranes)
Mydriasis means pupillary _______; while miosis means pupillary _______.
enlargement;constriction
Because Alpha 2 receptors are located on nerve terminals, they are referred to as ________
presynaptic aka prejunctional
What is a neuroeffector junction?
A neuroeffector junction is a site where a motor neuron releases a neurotransmitter to affect a target—non-neuronal—cell.
where an action potential is initiated slide 9
Preganglionic neuron extends from CNS to a
ganglion
postganglionic neuron extends form the ganglion to _____
effector organ or gland
In the PSNS, Preganglia are long with a short post ganglia. In the sympathetic, the preganglia are _____ and the post ganglia are _____.
short (from spine to chain of symp gang);
Long
When would Inderal (propranolol) not be given?
It is a non specific beta adrenergic blocker
• DO NOT USE or take great caution with Diabetic patients (and hepatic dysfunction). Diabetes Melittus, cannot feel when sugar is low (hypoglycemia).
non specific beta adrenergic blocker (Used for HTN, Angina)
Adverse effects - Dizziness, insomnia, bronchospasm, heart block, hypotension, bradycardia
What medications are preferred used post MI?
Post CHF?
Alpha and Beta Blockers:
- Propranolol/Inderal: prevents reinfarction AFTER MI
PR/IN=PRevents INfarction - CHF: Carvedilol (Coreg) lengthen life span of those who have CHF.
(LABETALOL (Trandate) is also used to treat CHF)
Sympathetic blocker works in SNS to antagonize beta 1&2 and alpha 1&2. What are some general issues with Alpha and Beta Blockers?
(Slide 40 - underlined)
General issues:
- Hides symptoms of hypoglycemia (diabetics must be careful)
- Beta blockers can cause rebound hypertension if stopped cold turkey
The drug labetalol (Trandate) is used to treat hypertension. What is the biggest benefit to using this drug over others?
Remember LOL is a beta blocker.
slide 42
INCREASED RENAL PERFUSION with decreased renin.
Di huang can inact this med.
-Know medication that would treat non obstructive urinary retention?
Direct acting Cholinergic =
Bethanechol (Duvoid, Urecholine) THESE ARE ALL THE SAME
Works by increasing tone of bladder muscles; increasing urination; relaxes sphincter (which can be too effective and lose bladder anal sphincter control) of course this means Urinary Urgency …cuz if your sphincters are loose, shit just got urgent.
- Binds to cholinergic receptors
- Resists AChase
- Muscarinic agonist
What does direct acting cholinergic?
Direct – acts on the cholinergic receptor/occupies receptor sites for ACh causing an increased stimulation of the receptor
What does indirect acting cholinergic?
Indirect – blocks acetylcholinesterase from destroying (breaking down) acetylcholine which allows a build up of the body’s natural ACh in the synaptic clef.
What is the impact of too much acetylcholinesterase inhibitor on the body?
Creates same symptoms of muscle weakness and respiratory paralysis as i we give too little. Too much, too little has same effect.
-Impact of too much acetylcholine on the body.
Couple examples
• Stomach gets upset: vomiting, diarrhea (gi tract over stimulated)
• We have these receptors everywhere!!!!
-What is the adverse drug reactions/interactions with other medications associated with Aricept?
It is used to treat alzheimer’s
drug-drug interaction NSAIDS, risk of G.I bleeding and respiratory problems and anemia
Other side effects:
Donepezil (Aricept) Adverse effects:
As with all ACh… nausea, vomiting, diarrhea; Agitation; Anxiety and depression;
bradycardia/hypotension/imcreased GI secretions, activity and bladder tone, relaxation of GI and genitourinary sphincters (so of course you have more GI secretions)
• Binds to cholinergic receptors
• Inhibits AChase
Aricept also treats alzheimer’s – alzheimer’s is a deficiency of ACh producing neurons…axon dissolves –tangles with T protein - and you get gummy blockages –neuritic plaques…plaques block signals…so you need a TON of ACh )
What are common adverse reactions to Alpha & Beta Adrenergic as a group?
It’s a PHAAD
P alpitations H ypertension A rrhythmias A ngina D yspnea
What is a the action of isoproterenol (Isuprel)?
Treats:
- shock
- cardiac standstill
- heart block in transplanted hearts. (when upper and lower parts of heart are not coordinating).
- Prevents bronchospasm during anesthesia;
- inhaled to treat bronchospasm
What happens? HR ^ BP^ HYPERglycemia for diabetics
Side effects of Atropine?
Anticholinergic Agent
- Blurred vision
- mydriasis - (excessive pupil dilation)
- cyclopegia - (loss in visual accommodation the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies. Accommodation acts like a reflex, but can also be consciously controlled.)
- PHOTOPHOBIA (sensitive to light – eyes/skin),
- PALPITATIONS AND TACHYCARDIA
- Dry mouth
- shuts down GI and urinary tract.
Per lecture:
If you have bradycardia: Raises HR and BP effectively
Used preop to remove saliva (dry secretions…), shut down parasymp (relaxes GI tract) to put in endotrach without upper gi issues. Can’t pee. No peristalsis (the reason anticholinergic is used for IBS diarrhea and nausea/motion sickness)
What is cyclopegia?
Loss in visual accommodation
Alpha Blocker - Phentolamine (Regitine) is used for management of HTN during renal tumor surgery, what are the adverse effects of?
Alpha blocker - critical think…it vadodilates …. if you had high BP, it would decrease BP….if we decrease BP what happens?????
Adverse effects:
- hypotension
- orthostatic hypotension
- angina and MI and CVA, Arrhythmia, weakness and dizziness
Alpha blocker –works on blood vessels, causing vasodilation to reduce HTN
Body wants to get constant CO When reduce BP = Increase HR to maintain CO…veins open= less pressure so more HR to maintain CO
What family of drugs treats myasthenia gravis?
(Myasthenia Gravis is when ACh doesn’t reach end muscle plate because there are antibodies to ACh. The person loses muscle control because no ACh is getting to muscle plate. YOu have to do something to get the ACh to build up and get to the muscle plate)
Also used to reverse nerve gas for military.
Acetylcholinesterase Inhibitors:
Prototype:
- Indirect acting cholinergic
- pyridostigmine (Regonol, Mestinon)
allows build-up of body’s own ACh.
What is the diagnostic agent for Myasthenia Gravis?
• EDROPHONIUM is a diagnostic agent for Myasthenia gravis; reverse it for about two minutes then pt falls back down..
(Tensilon, Enlon)
-How would you reverse a cholinergic reaction?
You need an anticholinergic or cholinergic antagonist
Pralidoximine (antidote for acetylcholinesterase inhibitors)
Laymen’s: Acetylcholinesterase was being blocked by an indirect cholinergic acting agonist, allowing acetylcholine to build up. We give Pralidoximine to stop that action, so the acetylcholine is being broken down again and the amount decreases.Since it is acting on ACh-ase, it is considered working to reverse on an indirect.
-Older adults have greater number of adverse drug reactions – why?
- Decreased kidney and liver function (excretion/metabolism)
- Decreased blood circulation/CO
- Polypharmacy - on too many medications
-How/Were does the body make acetylcholine and nor epinephrine?
Acetylcholine is a neurotransmitter that is synthesized in certain neurons by the enzyme choline. –>Released at end of presynapse in SNS + in the postsynapse in the PSNS.–>Recptors are muscarinic and nictoinic.
Norepinephrine is synthesized by tyrosine, released by postgannglionic neurons in the SNS. Receptors are alpha and beta
- How do Alpha 1 blocking agents impact BPH?
Hint: Alpha 1 effects blood vessels
Use doxazosin so you can go Son!
Reduction of BPH = you can pee!
Prototype: Doxazosin (Cardura) is an Alpha 1 selective blocker that causes vasodilation and reduced vascular tone
Best to give to elder gents with prostate issues + HTN. (taking this helps voiding; drops BP by opening blood vessels.)
Adverse Effects: hypotension
(Vascular tone refers to the degree of constriction experienced by a blood vessel relative to its maximally dilated state. All arterial and venous vessels under basal conditions exhibit some degree of smooth muscle contraction that determines the diameter, and hence tone, of the vessel.)
Other drugs used to treat: Flomax aka tamsulosin
How do the neurotransmitters work?
When / where are these neurotransmitters released?
General rule: dendrite–>cell body–>axon–>synaptic clef–>CONTINUES until hits–>target
Travel from one neuron to the next sending signals unti lit hits target receptor/organ and final action takes place
Acetylcholine is released at end of presynapse in SNS + in the postsynapse in the PSNS.–>Receptors are muscarinic and nictoinic.
Norepinephrine is released by postgannglionic neurons in the SNS. Receptors are alpha and beta
Know the difference between nicotinic and muscarinic receptors?
Nicotinic = volunteer (neuromuscular junction) Muscarinic = visceral; involuntary.
T or F: You should always check the apical pulse for a beat of 60 or more before administering heart medication.
True
How do you position a pt who has hypotension?
trendelenburg
Why should you avoid taking NSAIDs if you have heart disease?
It increases the risk of heart attack by 50%.
Do NOT take with beta blocker esp. Atenolol interacts!
What is the best drug to use after a heart attack?
Beta 1 selective atenolol (Tenormin)
T or F: Epinephrine can cause hypoglycemic feelings due to sugar dump from liver.
True
Alpha and Beta adrenergic AGONISTS as a group
INDICATIONS/AVERSE REACTIONS?
Alpha and Beta adrenergic AGONISTS as a group
1. INDICATIONS -Treats shock, glaucoma, prolongs anesthetic effect, asthma
- ADVERSE REACTIONS- Arrhythmias, HTN, palpitations, angina, and dyspnea
Adrenergic blocking agents as a group - Inhibit SNS
- Hide symptoms of hypoglycemia
- Beta blockers cause rebound hypertension
- Increased renal profusion (trandate or labetalol)
- Decrease HR/BP
Why should you ask about supplements or homepathic meds?
Di Huang, ginseng and St. Johns antagonize drugs
How Do Adrenergic Drugs Work?
Adrenergic drugs stimulate the adrenergic nerves. The structures of the drugs closely resemble the neurotransmitters that your body produces during times of stress, such as norepinephrine. Norepinephrine acts directly on the adrenergic receptors. Therefore, adrenergic drugs are able to interact with the same receptor sites as the neurotransmitter.
Examples of the affects adrenergic drugs can have on the body include:
increasing blood pressure constricting blood vessels opening the airways leading to the lungs increasing heart rate stopping bleeding
If you are taking decongestant NeoSynephrine (phenylphrine), it is constricting to help you breath. If you constrict, you have the risk of increased BP. So if you send someone home with this drug who is at risk for high BP, what do you tell them to do at home?
monitor BP at home
Make up silly ways to remember things. “Uncle Don has Alzheimer’s so he takes DONepezil.” Now, what is the trade name for this one?
aricept
Ari doesn’t except that he has alzheimers
Anything that works on the heart can cause….
arrhythmia, weakness, dizziness
Cholinergic drugs have common adverse affects which include….
anxiety and depression and dry mouth
nausea vomiting diarrhea (seems like for ALL drugs we have studied…because ACh in all presynapse perhaps.)
If a drug is an anticholinergic, will it effect both SNS and PSNS?
Yes because all pre synapse have ACh for a neurotransmitter. More so on PSNS because both per and post synapse use it…
How do anticholinergic drugs act?
by competing (blocking) for the muscarinic receptor sites in the involuntary side…. does not touch nicotinic.
If the drug is sitting in the receptor, how is the ACh also gonna sit there? It’s like musical chairs….. only so many seats. Drugs beat the ACh to the seat.
What happens when you use anticholinergics?
Well it is anti or against the normal functions of PSNS which are to rest and digest…which means SNS can take over… If you have a sympathetic reaction to the tiger….what happens?
Increase HR
decreased GI
decreased bladder tone and function
pupils dilate (hen that happens you experience cyclopegia aka lack of accommodation).
