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Autonomic drugs work by acting as either an _______ or _______
agonist or antagonist
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Agonist _________ and produce a _______ response
- bind to the receptor on the tissue
- maximal, where it's excitatory or inhibitory
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Antagonist _______ and cause a ________ response
- Bind to receptors and block and reverse the effects of the neurotransmitter
- submaximal
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Sympathomimetics or _______ has what function
- adrenergic agonists
- mimic/increase sympathetic function
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Sympatholytics, ________ or _______ has what function
- adrenergic blockers, sympathetic blockers
- these block/stop sympathetic function
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Parasympathomimetics or ___________ act to _______
- cholinergic agonists
- mimic or increase parasympathetic function
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Parasympatholytics, __________ or _________ act to __________
- anticholinergic agents, or cholinergic blockers
- block or stop parasympathetic function
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The most striking and characteristic actions of sympathomimetic drugs are exerted on the ________ system
cardiovascular
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Adrenergic (Sympathetic) Agonists: are divided into drugs that are:
- Direct acting
- Indirect acting
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What are direct acting drugs
bind directly to and activate the alpha or beta receptors, imitating the action of the neurotransmitter
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What are indirect acting drugs
do not themselves bind to the receptor, but cause release of NE from the nerve terminals. Then, the NE interacts with the receptor site
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Alpha1-receptors are located on the
smooth muscles of the blood vessels supplying organs such as the heart, skin, and salivary glands and smooth muscle of the eye, glands, GI tract, and urinary bladder
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Pharmacological activation of Alpha1-receptors leads to
vasoconstriction, dilation of the pupils (let’s more light in), and contraction of isolated smooth muscle
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The Exception to the stimulation of Alpha1-receptors is in
the intestine leads to intestinal relaxation
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Alpha2-receptors are located on the
–Located on the terminals of neurons that are releasing NE. Many are centrally located - i.e. in the CNS
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Activation of the Alpha2 receptor by released NE
reduces further NE release
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Beta1-receptors are located ________ and the stimulation leads to _______
- Located on heart muscle
- increased heart rate
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Beta2-receptors are located _________ and the stimulation leads to ________
- Located on smooth muscle of the bronchioles (lungs) and intestines, and bloods vessels supplying the heart
- relaxation of smooth muscle
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The drug Epinephrine stimulates both _____ and _______ receptors
alpha and beta
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Epinephrine is a powerful _________ through alpha1 receptors
vasoconstrictor
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What relief does Epinephrine provide with the activation of the beta 1 receptor
Powerful cardiac stimulant used in heart failure
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What relief does Epinephrine provide with the activation of the beta 2 receptors
Powerful relaxation of smooth muscle in the lungs with bronchodilation. Used in severe asthmatic emergency
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Epinephrine is added in with dental local anesthetics to
prolong the localized activity of agent through vasoconstriction
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Subcutaneous injections of epinephrine in low doses as used in dentistry will stimulate predominately __________ receptors which results in __________
- Beta-2
- vasodilation of skeletal and smooth muscle causing a decrease in diastolic blood pressure
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If some epinephrine also stimulates Beta-1 receptors this will result in
an increase in cardiac output resulting in an increase in systolic blood pressure
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levonordefrine (________)– is a _________ and unlike epinephrine it has mostly _______ intercation
- Neo-Cobefrin
- Vasoconstrictor used in local anesthetic agents.
- alpha1 interaction with little or no effect on the Beta adrenergic receptors
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phenylephrine (__________)– causes ________
- Neo-Synephrine
- Causes vasoconstriction. Used in nasal sprays where it shrinks vessels in stuffy nose opening airway. Rebound effect leads to “nose spray junkies”.
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Direct-Acting Adrenergic Receptor Agonists that are central alpha2 agonists work in the ________ by stimulating the ______ which decrease
- CNS (brain)
- by stimulating the alpha2 (preganglionic) receptors
- sympathetic outflow of NE from the nerve terminals. Works like blockers (antagonists).
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central alpha2 agonists leads to
lower blood pressure due to less norepinephrine being released
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clonidine (______) –
- Catapres
- prototype of central 2 agonist
- used to lower blood pressure
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Beta 1 /Beta 2 Adrenergic Agonists are used in the treatment of _________ and affect the ______ receptors causing _________ and _________
- in the treatment of bronchial asthma
- B2-adrenergic receptors
- causing dilation of the bronchial smooth muscle and vasoconstriction of the bronchial blood vessels
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Isoproterenol (______)
- Isuprel
- prototype of Beta 1/Beta 2 Adrenergic Agonist.
- Nonselective so it acts on both B1 and B2 receptors therefore it also affects the heart by causing increased heart rate (B1)
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albuterol (______,______)–
- Ventolin, Proventil
- specific beta2 agonist. Opens lung passages. Used in rescue inhalers for asthma. Since it is selective for B2, there are less effects on the heart
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amphetamine (_______)–
- Adderall
- lipophilic drug w/powerful CNS effects leading to huge catecholamine release. Leads to increased alertness, relief of fatigue, euphoria, increased number of errors. - increases release of dopamine in the synaptic cleft
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cocaine –
naturally occurring, the most potent vasoconstrictor, used as a local anesthetic. Adrenergic effects include cardiac stimulation and elevation of blood pressure
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methylphenidate (______) -
- Ritalin
- Used to treat ADHD and narcolepsy. Prevents reuptake of dopamine from the synaptic cleft.
- These drugs are abused by high school and college students who purchase these agents for “help” on exams
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ephedrine and pseudoephedrine (______).
- Sudafed
- Used as nasal decongestant
- These are also used for the illicit manufacture of methamphetamine. Therefore, consumers can only buy 3.6 grams in one day, and a total of 9 grams per month
-
methamphetamine-
“Meth” is more lipid soluble w/ more CNS activity. Leads to huge central release of neurotransmitters causing euphoria and excitement. Tremendous addictive potential
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What are the Therapeutic Uses of Sympathetic Agents Alpha 1 receptors
α1-receptor agonists cause smooth muscle contraction, which leads to vasoconstriction, dilation of the pupils, and contraction of the bladder muscle. These drugs are used in the treatment of shock and hypotension and as a nasal/ocular decongestant
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What are the Therapeutic Uses of Sympathetic Agents Alpha 2 receptors
α2-receptor agonists are used in the treatment of hypertension to lower blood pressure. These drugs will inhibit the release of NE, resulting in lower levels of NE
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What are the Therapeutic Uses of Sympathetic Agents β1 receptor
β1-receptor agonists are used to increase the rate and force of heart contractions (cardiac stimulation) in patients with hypotension and shock. These drugs are given intravenously
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What are the Therapeutic Uses of Sympathetic Agents β2-receptor
β2-receptor agonists are used to cause relaxation or dilation of smooth muscle in the lungs (bronchodilation) in patients with asthma. These long-acting drugs are given orally or inhaled. It is best to choose a selective β2 drug such as albuterol (Ventolin, Proventil) or terbutaline (Brethine) to keep adverse side effects to a minimum
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Tricyclic antidepressants act by blocking the
reuptake of catecholamines and may increase the hypertensive effects of epinephrine
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Sympatholytic Drugs are agents that
directly (competitively) block alpha or beta receptors
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Alpha1 Adrenergic Receptor Antagonists (Blockers) are agents that __________ and are clinically useful for _______
- block sympathetic stimulation of alpha1 preventing the contraction of smooth muscle in the vessels of the skin or along the course of the urethra
- lowering blood pressure and making it easier to urinate in benign prostatic hyperplasia (BPH)
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Alpha1 Adrenergic Receptor Antagonists (Blockers) have drugs names ending in ______
"zosin"
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-
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terazosin (_____) -
- Hytrin
- hypertension, prostate hypertrophy, urinary retention
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tamsulosin (_____) –
- Flomax
- Prostate hypertrophy
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What is an important dental note with patients taking alpha blockers for hypertension
patients can get faint or dizzy when moving the chair from a supine to an upright position due to orthostatic hypotnsion. Keep the patient from getting up for a few minutes to prevent a fall
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Beta Blockers block either _________ or ______ they are drugs
both beta1 and beta2, or are selective for one or the other
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Beta blockers are drugs that end in
olol
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Beta Blockers are used in the treatment of
cardiovascular disease such as hypertension, angina, and heart arrhythmias as well as panic attacks, migraine headaches, glaucoma
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Non-Selective Beta Blockers causes many adverse effects such as
bronchospasm, bradycardia, and hypoglycemia
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propranolol (______)
- Inderal
- is the prototype non-selective B blocker. Used to treat hypertension by decreasing cardiac output and blood pressure
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-
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carvedilol (______)-
- Coreg
- More commonly encountered. Blocks both beta2 and alpha1 receptors treating hypertension and atrial fibrillation
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CHOLINERGIC AGONISTS have the following effects:
- Cardiovascular: Decrease rate and force of heart beat through vagus nerve activation
- GI/Urinary Tract: Increase in muscle contraction (peristalsis), muscle tone, and secretions (including salivary flow)
- Eye: Miosis (constriction of pupil)
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What are the two types of cholinergic agonists
- Direct Acting Cholinergic Agonists
- Indirect Acting Cholinergic Agonists– also referred to as cholinesterase inhibitors
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acetylcholine (Ach)–
has almost no clinical use because it is rapidly destroyed and causes many adverse effects
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bethanechol (________)–
- Urecholine
- Prevents urinary retention and increases intestinal motility after surgery
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pilocarpine (_______) -
- Salagen
- Treats xerostomia usually in head and neck radiation and Sjogren’s syndrome by increasing saliva (sialogogue). Treats glaucoma by decreasing intraocular pressure
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cevimeline (_______)–
- Evoxac
- Drug for xerostomia that is more specific to receptors on salivary glands therefore has fewer side effects
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tacrine (______) -
- Cognex
- Treats Alzheimer’s disease
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donepezil (______) -
- Aricept
- Treats Alzheimer’s disease
-
malathion
(insecticide)- irreversible binding to AChase
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sarin
(nerve gas) -irreversible binding to AChase
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scopolamine
motion sickness, dispensed in transdermal patch
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atropine
used in dentistry to create xerostomia and a dry operative field
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tolterodine (______)
- Detrol
- increases bladder volume, used to treat incontinence
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oxybutynin (________)
- Ditropan
- antispasmodic action on bladder muscle decreasing urge to void
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Cholinergic drugs are primarily used in the treatment of
xerostomia (cevimeline, pilocarpine) and Alzheimer’s disease (donepezil, tacrine, rivastigmine)
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Anticholinergic drugs are used to
increase heart rate (atropine) and to treat urinary incontinence (oxybutynin), motion sickness (scopolamine), and irritable bowel syndrome (dicyclomine, propantheline, scopolamine)
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Parasympathomimetics (cholinergic drugs) have few therapeutic uses because
of their numerous side effects.
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Name some Cholinergic receptor ANTAgonist
- scopolamine
- atropine
- tolterodine (Detrol)
- oxybutynin (Ditropan)
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Name some Indirect acting cholinergic agonist
- tacrine (Cognex) – Treats Alzheimer’s disease.
- donepezil (Aricept) – Treats Alzheimer’s disease
- malathion (insecticide) - irreversible binding to AChase
- sarin (nerve gas) - irreversible binding to AChase
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Name some Direct acting Cholinergic Agonist
- acetylcholine (Ach)– (prototype) has almost no clinical use because it is rapidly destroyed and causes many adverse effects
- bethanechol (Urecholine)– Prevents urinary retention and increases intestinal motility after surgery
- pilocarpine (Salagen) – Treats xerostomia usually in head and neck radiation and Sjogren’s syndrome by increasing saliva (sialogogue). Treats glaucoma by decreasing intraocular pressure
- cevimeline (Evoxac)– Drug for xerostomia that is more specific to receptors on salivary glands therefore has fewer side effects
- Nicotine – used for smoking cessation
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Name an Adrenergic Alpha and Beta Blocker
carvedilol (Coreg) – second drug of its class. More commonly encountered. Blocks both beta2 and alpha1 receptors treating hypertension and atrial fibrillation
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Name some Selective Beta1 Blockers
- atenolol (Tenormin) - hypertension
- metoprolol (Lopressor) – hypertension
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Name a non-selective beta blocker
propranolol (Inderal) – is the prototype non-selective B blocker. Used to treat hypertension by decreasing cardiac output and blood pressure
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Name some Alpha1 Adrenergic Receptor ANTAgonists (Blockers)
- prazosin (Minipres) - hypertension
- doxazosin (Cardura) - hypertension
- terazosin (Hytrin) – hypertension, prostate hypertrophy, urinary retention
- tamsulosin (Flomax) – Prostate hypertrophy
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Name some Mixed -Acting Adrenergic Receptor Agonists
- ephedrine and pseudoephedrine (Sudafed). Used as nasal decongestant. These are also used for the illicit manufacture of methamphetamine. Therefore, consumers can only buy 3.6 grams in one day, and a total of 9 grams per month
- methamphetamine - “Meth” is more lipid soluble w/ more CNS activity. Leads to huge central release of neurotransmitters causing euphoria and excitement. Tremendous addictive potential. Meth high lasts much longer than using crack (1 hour vs. 12).
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Name some Indirect -Acting Adrenergic Receptor Agonists
- amphetamine (Adderall)– lipophilic drug w/powerful CNS effects leading to huge catecholamine release. Leads to increased alertness, relief of fatigue, euphoria, increased number of errors. - increases release of dopamine in the synaptic cleft
- cocaine – naturally occurring, the most potent vasoconstrictor, used as a local anesthetic. Adrenergic effects include cardiac stimulation and elevation of blood pressure
- methylphenidate (Ritalin) Used to treat ADHD and narcolepsy. Prevents reuptake of dopamine from the synaptic cleft.
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Name some Direct acting Beta 1 /Beta 2 Adrenergic Agonists
- isoproterenol (Isuprel)- is the prototype for Beta 1 /Beta 2 Adrenergic Agonists. Drugs used in the treatment of bronchial asthma affect the B2-adrenergic receptors. Causes dilation of the bronchial smooth muscle and vasoconstriction of the bronchial blood vessel. Nonselective so it acts on both B1 and B2 receptors therefore it also affects the heart by causing increased heart rate (B1).
- albuterol (Ventolin, Proventil)– specific beta2 agonist. Opens lung passages. Used in rescue inhalers for asthma. Since it is selective for B2, there are fewer effects on the heart
-
Name some Direct acting Alpha Adrenergic Agonists
- levonordefrine (Neo-Cobefrin): Vasoconstrictor used in local anesthetic agents. Unlike epinephrine, has mostly alpha1 interaction with little or no effect on the Beta adrenergic receptors.
- phenylephrine (Neo-Synephrine)– Alpha1 agonist. Causes vasoconstriction. Used in nasal sprays where it shrinks vessels in stuffy nose opening airway. Rebound effect leads to “nose spray junkies”.
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