Chapter 4 Autonomous Drugs Flashcards
1
Q
Vasoconstrictors added to some LA & drugs used to ^ salivary flow are _________
A
ANS drugs
2
Q
Some ANS drugs produce oral adverse reactions. Example?
A
Anticholinergic drugs cause xerostomia
3
Q
Members of other drug groups have effects similar to those of ANS drugs. Example?
A
Antidepressants and antipsychotics are drug groups with autonomic side effects, specifically anticholinergic effects
4
Q
ANS functions in
A
Regulation of BP, heart rate, GI tract motility, salivary gland secretions, and bronchial smooth muscle.
5
Q
ANS system relies on
A
specific neurotransmitters (chemicals released to send messages) and a variety of receptors to initiate functional responses in target tissues
6
Q
Each division of ANS (PANS and SANS) anatomy
A
Afferent (sensory) fibers (What’s happening?), central integrating areas (Let’s coordinate all this info! Hey, what did you find out?), efferent (peripheral) motor preg. (This is what’s happening) fibers and postg. fibers (Heart, begin beating!)
7
Q
The preg. neuron originates in the ________ and passes out to form the _________ at the synapse with the postg. neuron.
A
CNS, ganglia
8
Q
Space between preg. and postg. is termed __________
A
Synapse/synaptic cleft
9
Q
The postg. neuron originates in the ___________ and innervates ______________________
A
ganglia, effector organ/tissue
10
Q
__________ in the CNS give rise to the preg. fibers of the PANS. They originate in _________
A
Cell bodies; nuclei of III, VII, IX and X cranial nerves and S2-S4 of spinal cord
11
Q
The preg. fibers of the PANS are relatively ________ and extend near or into _________
A
long, innervated organ
12
Q
Distribution of preg. fibers in the III, VII and IX cranial nerves is relatively _______ whereas the X/vagus nerve has a ________ distribution
A
simple, complex
13
Q
Postg. fibers of PANS originating in _______, usually ______ and terminate on ________
A
ganglia, short, innervated tissue
14
Q
Cell bodies that give origin to the preg. fibers of the SANS span from __________ to the __________. Referred to as “in between” because ________
A
thoracic (T1), lumbar (L2) portion of the spinal cord. Distribution is between two locations of the innervation of the PANS
15
Q
Arrangement of SANS produces a ______ diffuse effect than PANS because ____________ then postg. fibers terminate at the ____________
A
more, a single SANS preg. fiber often synapses with numerous postg. fibers and because adrenal medulla release epi into bloodstream, effector organ or tissues
16
Q
Adrenal medulla is also innervated by the _________. Functions much as a large _________ with glands in the medulla representing __________
A
SANS, sympathetic ganglion, postg. component.
17
Q
When SANS is stimulated, the adrenal medulla releases primarily ________ and a small amount of _________ into systemic circulation
A
epi, norepinephrine (NE)
18
Q
PANS is concerned with ________ SANS designed to cope with _________ such as __________.
A
conservation of body processes (digestion and intestinal tract motility), sudden emergencies such as “fight-or-flight”
19
Q
SANS stimulates radial smooth muscle producing an _________. PANS stimulates circular smooth muscle producing a __________.
A
increase in pupil size (mydriasis), decrease in pupil size (miosis)
20
Q
T/F Sensory fibers in one division can influence motor fibers in another.
A
True
21
Q
Neurotransmitter function
A
carry messages
22
Q
Communication between nerves or between nerves and effector tissue takes place through __________________
A
Release of chemical neurotransmitters across the synaptic cleft
23
Q
Neurotransmitters are released in response to the _____________ to _____________
A
Nerve action potential, interact with receptor
24
Q
T/F Receptors are only found on the postsynaptic fiber and effector organ
A
False; Receptors are usually found on the postsynaptic fiber and effector organ but may be located on the presynaptic membrane
25
Disposition of the neurotransmitter occurs most often by either its ___________________ or _______________
reuptake into the presynaptic nerve terminal, enzymatic breakdown
26
Nerves in ANS contain necessary enzyme systems and other metabolic processes to _____________________
synthesize, store and release neurotransmitters
27
Drugs can modify ANS activity by altering any of what events associated with the neurotransmitters?
synthesis, storage, release, receptor interaction and disposition
28
Between preg. and postg. neurons
Acetylcholine (ACh) is the neurotransmitter in the synapse (ganglion) formed in this area. Nerves that release ACh are termed cholinergic, also stimulated by nicotine so termed nicotinic as well.
29
Between postg. and effector tissues
PANS: Neurotransmitter released from postg. nerves is ACh, cholinergic. Because postsynaptic tissue responds to muscarine, termed muscarinic.
SANS: NE is the transmitter released by postg. nerves; designated as adrenergic
30
Neuromuscular junction
Although not within ANS, neuromuscular junction of skeletal muscle releases ACh, cholinergic
31
If the postsynaptic tissue is a postg. nerve _______________
Depolarization with generation of an action potential occurs in that neuron
32
The action of released ACh is terminated by ___________
hydrolysis by acetylcholinesterase to yield the inactive metabolites choline and acetic acid (acetate)
33
3 ACh receptor sites
PANS, ganglions, neuromuscular junction
34
Once ACh is released from the presynaptic neuron into the synaptic cleft, it can bind to either ______ or _____________
muscarinic or nicotinic receptor sites
35
Small doses of ACh bind to ________. Large doses bind to __________
muscarinic, nicotinic receptors
36
Nicotinic receptors are found in the _______________
neuromuscular junction, PANS, SANS, adrenal medulla, and CNS
37
Muscarinic receptors are found only in the _____________
PANS, SANS and CNS
38
What determines which receptor site is activated?
The amount of neurotransmitter released, the size of the synaptic cleft, and the postg. site.
39
Cholinergic (parasympathomimetic) agents are classified as ________ or __________
Direct acting (acts on receptor), indirect-acting (causes release of neurotransmitter)
40
(PANS) Direct-acting agents include the ___________ and ___________
choline derivaties (include both ACh and other, more stable choline derivatives; these ACh derivatives possess activity similar to PANS stimulation but have a longer duration of action and are more selective), pilocarpine
41
The indirect-acting parasympathomimetic agents or cholinesterase inhibitors act by _______________
inhibiting the enzyme cholinesterase
42
Cardiovascular effects associated with the cholinergic agents are result of both direct and indirect actions. The direct effect on the heart produces ___________. Indirect effect of cholinergic agents is _________________. With indirect and direct effects (opposite), resulting effect depends on ______________. Generally, there is ____________.
a negative chronotropic and inotropic action > A decrease in cardiac output > Vasodilation > Decrease in total peripheral resistance, increase in heart rate and cardiac output, concentration of drug present, bradycardia
43
Cholinergic agents:-
GI effects:
Eye effects:
Brain effects:
- activity, motility, and secretion
- miosis and cycloplegia (paralysis of ciliary muscles result in loss of visual), tx of glaucoma
- Acetylcholinesterase inhibitors boost cholinergic and compensate for loss of functioning brain cells
44
Cholinergic agents adverse reactions
When large doses ingested, SLUD: Salivation, lacrimation, urination and defecation. Even larger doses cause paralysis result of effect on neuromuscular junction. Toxic doses: confusion
45
Tx of overdose of cholinesterase inhibitors
insecticides or organophosphates (also called parathion, combination of pralidoxime -regenerates irreversibly bound ACh receptor sites that are bound by inhibitors- and atropines -blocks the muscarinic effect of the excess ACh)
46
Contraindications of cholinergic agents
Asthma, hyperthyroidism, GI obstruction, severe cardiac disease (tachycardia), myasthenia gravis bc neostigmine occupies the enzyme and irreversible cholinesterase inhibitors will not function, peptic ulcers (acid secretion)
47
Direct-acting agents cholinergic use
Glaucoma , occasionally myasthenia gravis that reduce the effect of ACh, urinary retention after surgery
48
Pilocarpine, a cholinergic agent for xerostomia, also topical glaucoma has side effects of:
Perspiration, nausea, rhinitis, chills and flushing
49
Physostigmine (Antilirium) used to
treat several kinds of drugs, acute toxicity from anticholinergic agents
50
Indirect-acting cholinergic agents used to
glaucoma, myasthenia gravis, AD dementia.
51
Donepezil (Aricept) approved by FDA for and Rivastigmine for
tx of mild, moderate and severe AD dementia, mild-mod AD, side effects: nausea, vomiting, diarrhea, bradycardia
52
Cholinesterase inhibitors for insecticides and chemical warfare are
irreversible cholinesterase inhibitors, (parathion, malathion and sarin)
53
T/F The release of ACh is not prevented by anticholinergic agent but receptor site is completely blocked, thus they're called antimuscarinic agents because they block the action of ACh on smooth muscles, glandular tissue and the heart.
True
54
Anticholinergic agents CNS effects:
Depending on dose admin, can produce CNS stimulation or depression. Ex: usual doses of scopolamine often cause sedation, atropine in high doses causes stimulation
55
Atropine and scopolamine are tertiary agents and propantheline and glycopyrrolate are quaternary. Because of their water solubility _____________ do not penetrate CNS well (fewer CNS adverse reaction. The tertiary agents are ____________ and can easily penetrate brain
quaternary, lipid soluble
56
```
Anticholinergic agents effects:-
Exocrine glands secretion:
Smooth muscles:
Eye:
CV:
```
- Reducing flow and volume
- Relax in respiratory and GI tract (Ipratropium, anticholinergic inhaler for asthma)
- mydriasis and cycloplegia (paralysis> visual loss)
- large doses, can produce vagal blockade, tachycardia (direct), small doses bradycardia (indirect)
57
Effect of anticholinergics on GI has given rise to the name ________________
"spasmolytic agents" If used repeatedly, constipation can result
58
Adverse reactions of anticholinergics
Xerostomia, blurred vision, photophobia, tachycardia, fever and GI statis, hyperpyrexia (lack of sweating)
59
Anticholinergic toxicity can cause signs of
CNS excitation: delirium, hallucinations, convulsions, and respiratory depression
60
Contraindications of anticholinergic agents
glaucoma, prostatic hypertrophy (difficulty urinating), GI/urinary obstruction, CV disease
61
Uses of anticholinergic agents
preoperative med: inhibit saliva secretion and bronchial mucus, block vagal slowing of heart from LA, gastric ulcers, overactive bladder (OAB), ophthalmological exam, reduction of Parkinson-like movements (before levodopa came) experience dry mouth and blurred vision. Now used occasionally with levodopa. Phenothiazines used for psychoses cause (Parkinson-like) side effects, trihexyphenidyl and benztropine reduce rigidity and tremor. Scopolamine, CNS-depressant for motion sickness.
62
Drug interactions anticholinergic agents
Anticholinergic effects of other agents: phenothiazines, antihistamines, tricyclic antidepressants
63
Nicotinic agonists in low doses produce ____________. At high doses, produces ___________
stimulation through depolarization, paralysis of the ganglia > respiratory paralysis, peripherally increase BP, heart rate and GI motility
64
NE and epinephrine are synthesized in __________ and stored in __________. With stimulation, epi is released from ____________ and distributed via blood.
neural tissues, synaptic vesicles, adrenal medulla
65
Catecholamine: Catechol refers to _______________, amine refers to the _____________
1,2-dihydroxybenzene, chemical structure NH2
66
NE, epi and dopamine are endogenous sympathetic neurotransmitters that are ___________. Isoproterenol (Isuprel) is an exogenous ____________
catecholamine
67
Mechanisms of action of adrenergic drugs:
Direct-acting:
Indirect-acting:
Mixed-acting:
- Epi, NE, and isoproterenol act directly on receptor site.
- Amphetamine, release endogenous NE
- ephedrine, stimulate receptor directly or release NE
68
NE's action terminated by _______________. Two enzyme systems, ________________, involved in metabolism of both epi and NE
reuptake into presynaptic nerve terminal, stored for reuse. Monoamine oxidate (MAO) and catechol-O-methyltransferase (COMT)
69
Stimulation of a-Receptors results in ______________. Located in ______________
Smooth muscle excitation/contraction > vasoconstriction of skin and skeletal muscle
70
B-receptor types are B1 and B2. Excitation of B1 causes _____________. Stimulation of B2 results in ______________.
Stimulation of heart muscle > positive chronotropic (rate) and inotropic (strength) effect, metabolic effects on glycogen formation. Smooth-muscle relaxation, bronchodilation (for asthma).
71
Propranolol is _______________
B-blocker
72
Epi has both ______________ activity. NE and phenylephrine stimulate mainly _________________. Isoproterenol act mainly on ______________.
a and B-receptor, a-receptors, B-receptors
73
```
Adrenergic agents effects:-
CNS:
CV (Heart):
(Vessels):
(BP):
```
- excite, higher doses: anxiety, apprehension, restlessness, and even tremors.
- NE: ^ force and strength of contraction > vasoconstriction > ^ peripheral resistance ^ BP > vagal reflex lowers heart rate. Epi constricts a-receptors, dilates b-receptors > widening of pulse pressure. Isoproterenol, vasodilation > triggers ^ heart rate
- a-receptor: vaso primarily in the skin and mucosa, b-receptor vasodilation of skeletal muscle.
- epi: rise in systolic, decrease in diastolic, NE: rise in both, isoproterenol: little change in systolic, decrease in diastolic
74
```
Adrenergic effects:-
Eye:
Respiratory system:
Metabolic:
Salivary glands:
Bladder:
```
- decrease in intraocular pressure, tx of glaucoma and mydriasis.
- relaxation of bronchial (B-receptor effect) tx of asthma and anaphylaxis.
- hyperglycemia from B-receptor, basal metabolic rate ^
- (sub glands) stimulated to release a small amount of thick, viscous saliva. Parotid has no sympathetic innervation (only para) + vasoconstriction = flow of saliva reduced.
- B3 (Mirabegron) relaxes bladder
75
Contraindications of adrenergic drugs
Uncontrolled hypertension, angina or hyperthyroidism > arrhythmias or myocardial infarction
76
Uses of adrenergic drugs:
Prolonged action for LA and reduce potential for systemic toxicity, hemostasis, decongestion (constricting vessels and reducing swelling of mucous membranes. With repeated use, can cause more problems than rebound congestion. Systemic or topical intranasal steroids are now preferred.
77
```
Cardiac effects of adrenergic agents:-
Tx of shock:
Tx of cardiac arrest:
More effects:-
Bronchodilation:
CNS stimulation:
```
- Controversial bc elevate lowered BP but tx shock is more important, agents with both a and B-receptors used.
- Especially epi
- asthma or emphysema, anaphylaxis
- Tx of ADD and narcolepsy with methylphenidate (Ritalin) and dextroamphetamine (Dexedrine), Deithylproion used as a "diet pill" not legitimate use, narcolepsy (deep sleep any time) treated with adrenergics.
78
Phenylephrine causes primarily ______________ stimulation. Used as _______________
a-receptor > vasoconstriction, tachycardia, reflex vagal bradycardia. mydriatic and nose sprays/drops to relieve congestion
79
Levonordefrin is _____________
a derivative of NE, a vasoconstrictor often added to LA, higher dose required to equal epi, resembles a-receptor stimulation
80
Ephedrine and pseudoephedrine are effective when taken ______ and have a longer duration of action. They have both ____________. Ephedrine is often used in combination with other agents for patients with ____________. Pseudoephedrine is also present OTC, designed for tx of _______________
orally, a and B receptor activity, direct and indirect action. Asthma as nonprescription remedies. Common cold/allergies (Sudafed). Also used to "cook" meth. Ephedrine no longer available, pseudoephedrine now kept with pharmacists
81
Dopamine is __________. It's both an _______________ used primarily in
neurotransmitter in parts of the CNS. a and B-agonist, tx of shock. Precursor of NE and epi synthesis
82
Dopamine first act on the __________. Higher doses stimulate the ___________ producing _________
B-receptors of the heart > + chronotropic and inotropic effect. a-receptor, vasoconstriction, exerts unusual vasodilating effect, ^ blood flow in certain vessels. Ventricular arrhythmias and hypotension can occur
83
Dipivefrin (Propine) used to _________. They decrease production of aqueous humor (clear fluid in eye) and increase outflow __________ and produce mydriasis. In vivo, metabolized to __________
treat glaucoma, (B-receptor), (primarily a-receptor). Epi, may produce fewer side effects, it penetrates eye better
84
T/F Adrenergic blocking agents can block all (a & b), or (a), (b), (a1), (a2), (b1), (b2) receptors
True
85
a-Adrenergic blocking agents:
inhibit vasoconstriction > decrease in total peripheral resistance > reflex tachycardia
86
Epinephrine reversal is when patients who are pretreated with a-blocking agents and are given epi, they will exhibit _____________. A-blockers also block _________. Examples are _________________. They are used in tx of ___________ and in diagnosis and tx of ____________. Other examples are ______________.
B-effects (vasodilation) > lowers BP, mydriasis, phenoxybenzamine, phentolamine, peripheral vascular disease (Raynaud syndrome, vascular spasms), pheochromocytoma (a catecholamine-secreting tumor of adrenal medulla),
tolazoline (Priscoline), prazosin (Minipress), terazosin (Hytrin) and doxazosin (Cardura) for hypertension, Raynaud and prostatic hypertrophy
87
B-blocking drugs generic names end in ______, they produce _________
olol, bradycardia and possible bronchoconstriction in asthmatics
88
B-blockers may be either _______ nonspecific such as _________ or specific such as ________ atenolol. Specific B-blockers have more activity on the _____________ than on the lungs. This produces fewer side effects.
propranolol (depresses heart, bronchoconstriction and causes hypoglycemia- for arrhythmias, angina, hypertension, migraine & pheochromocytoma), atenolol, heart & blood vessels
89
a and B-blocking agents such as __________ have suffix ending in _______ Selective in a-blocker and a ________________. Its for _____________
labetalol (Normodyne, Trandate), alol, nonselective B-blocker, tx of hypertension and produces a fall in BP without reflex tachycardia.
90
Neuromuscular blocking agents:-Nondepolarizing (competitive) blockers ex: ___________. It combines with nicotinic receptor and block action of _____. Can be overcome by admin. of _________ such as ________. They cause paralysis.
Depolarizing agents such as _______ attach to the nicotinic receptor and similar to ACh causes depolarization > muscle fasciculation, with time repolarization occurs leading to _________________. Can cause _____________ When used in LA with halothane, hereditary pt's have ________ Drug of choice for these pt's is _________ Small dose of ______ is admin. before succinylcholine to block fasciculations of it.
curare (d-tubocurarine), ACh > no depolarization of membrane > muscle contraction blocked. Cholinesterase inhibitors, neostigmine, vecoronium and pancuronium. succinylcholine, flaccid paralysis because of resistance to depolarization (only lasting a few mins- broken down by cholinesterase), arrhythmias, hyperkalemia and glaucoma. Hyperthermia, dantrolene. Curare.
