Chapter 4: Drugs used in Nervous System Disorders Flashcards
_ _ is the body’s primary communication and control center
Nervous system
Nervous system serves three functions
-Sensory
-Integrative (analysis)
-Motor (action)
Nervous system is very close with what other system
Endocrine
2 main divisions of nervous system
CNS and PNS
CNS
-brain and spinal cord
-control center of the entire nervous system
PNS
Somatic and autonomic nervous systems
Fundamental unit of all branches and divisions of the nervous system is the
neuron (nerve cell)
Neurons communicate with each other at the synaptic end-bulbs by releasing chemical messengers called
neurotransmitters
The most basic impulse conduction system through the nervous system is the
Reflex arc
What does a sensory neuron do
carry impulse from receptor to CNS
what does a motor neuron do
carries impulse to an effector organ (spinal reflex= if the impulse does not travel to brain)
Autonomic nervous system
portion of the nervous system that control unconscious body activity
Two neurons carry impulses to target structures
-axon of first neuron leaves the CNS and travels to ganglion
-second neuron travels to target structure
Effector organs
Heart
Bronchial smooth muscle
Blood vessels
GI tract
Urinary system
Eyes
Glands (sweat, pancreas, salivary)
Normally, target sites of ANS have both _ and _ innervation
sympathetic and parasympathetic
Sympathetic (__): fight or flight
adrenergic
Parasympathetic (__): homeostatic
Cholinergic
Stimulation of sympathetic ns
increases heart rate, RR, and blood flow to muscles; decrease GI function, causes pupillary dilation
Neurotransmitter for sympathetic system
preganglionic synapse: ACh
postganglionic synapse: epi or norepi
Neurotransmitter for parasympathetic ns
pre and postganglionic synapse: ACh
Parasympathetic stimualtion
Brings heart rate, RR, and blood flow to muscles back to normal levels; returns GI function to normal; constricts pupils to normal size
Adrenergic drugs and what do they mimic
epi or norepi; sympathetic nervous system
Drugs that mimic parasympathetic nervous system
acetylcholine (ACh)
Neurotransmitters can be _ or _ by use of the appropriate drugs
mimicked or blocked
Parasympathetic NS drugs
Cholinergic drugs
Anticholinergic
Sympathetic NS drugs
Adrenergic Drugs
Adrenergic Blocking drugs
Clinical uses of cholinergic drugs
-aid in dx of myasthenia gravis
-decrease IOP
-Stimulate GI activity
-Tx urinary retention
-Tx nausea
-Antidote neuromuscular blockers
Cholinergic drug used tx bladder atony
Bethanechol
Cholinergic drug that reduces IOP
pilocarpine
Cholinergic drug used to control vomiting and promote gastric emptying
metoclopramide
When is metoclopramide contraindicated
obstruction/ perforation
Adverse effects of cholinergic drugs
bradycardia, lacrimation, diarrhea, vomiting, intestinal rupture, increased bronchial secretions
What do anticholinergic drugs do
inhibit the actions of acetylcholine by occupying the acetylcholine receptors
Clinical uses for anticholinergic drugs
-prevent bradycardia before anesthesia
-dilate pupils for ocular exam
-organophosphate toxicity
Examples of most common anticholinergic drugs
atropine, glycopyrrolate
Adrenergic drugs work at receptor sites mediated by _ or _
epinephrine or norepinephrine
First drug of defense for sinus bradycardia
atropine
Adrenergic drugs may be classified as catecholamines or according to the specific receptor types activated:
Alpha-1, Alpha-2, Beta-1, Beta-2
Alpha-1 target organs and response
Arterioles, Urethra, Eye; Constriction, increased tone, dilation pupil
Alpha-2 target organs and response
skeletal muscle; constriction
Beta-1 target organ and response
Heart; increased rate, conduction, contractility
Beta-2 target organs and response
kidneys, skeletal blood vessels, bronchioles; renin release, dilation
What adrenergic drug is used to treat urinary incontinence
phenylpropanolamine
Clinical uses for adrenergic drugs
-stimulate HR in cardiac arrest
-reverse brochoconstriction in anaphylaxis
-correct hypotension
-treat urinary incontinence
Side effects of adrenergic drugs
tachycardia, hypertension, cardiac arrhythmias
Examples of adrenergic drugs
epi, norepi, dopamine, dobutamine, phenylpropanolamine, albuterol
how to recognize a beta blocker
ends in “lol”
Clincial uses for alpha 1 blockers
vasodilation, urethral spasms
Clinical uses for alpha 2
reversal agents (ex: yohimbine reverses xylazine: atipamzole reverses dexmedetomidine)
Clinical use for beta blockers
tx glaucoma, cardiac arrhythmias, HCM in cats
uses of CNS drugs
calming, seizure and pain control, anesthesia, restraint, behaviors, reversals, stimulate CNS, euthanasia agents
Classes of tranquilizers and sedatives
-Phenothiazines (acepromazine)
-Benzodiazepines (diazepam)
-Alpha2-adrenoceptor agonists (anesthesia drugs)
-Alpha2 antagonists- (reverse alpha 2 agonists)
Tranquilizer- what does it do
reduces anxiety
What do sedatives do
reduces mental activity and causes sleepiness
Phenothiazine derivatives
-believed to block dopamine (and alpha1 which causes CVS effects)
-causes sedation, relives fear and anxiety
-DOESN’T PRODUCE ANALGESIA
-side effects: LOWER SEIZURE THRESHOLD, hypotension, protrusion of 3rd eyelid, paraphimosis
EX: ACEPROMAZINE
Uses for benzodiazepines
anti-anxiety, produce muscle relaxation, reduce anxiousness, anticonvulsants, stimulate appetite (in cats)
Diazepam cannot be injected into a _
muscle (bc it is not water soluble)
All Benzodiazepines end in
(-am)
Midazolam is _ _ and absorbed well after IM injection
water soluble
Alpha 2 agonists causes
some analgesia, some muscle relaxation, decreased response to stimuli
Alpha 2’s can cause severe
bradycardia
Alpha 2 agonists
Xylazine, Detomidine, Romifidine, Dexmedetomidine
Yohimbine reverses
cardiovascular and sedative effects of xylazine
Atipamezole is a specific antagonist for
dexmedetomidine (dexdomator)
Analgesics are drugs that
relieve pain
Analgesics are categorized as
non-narcotic or narcotic
Narcotic analgesics are used for
moderate to severe pain
1 side effect of opioid overdose
respiratory depression
Opioids produce _ and _ and relieve anxiety
analgesia, sedation
used alone, Opioids DO NOT produce
general anesthesia
Opioid receptors
Mu- found in the pain regulating areas in brain
Kappa-found in cerebral cortex and spinal cord
Sigma- found in the brain
Delta-contribute to analgesia
Common agonist opioids (for severe pain control)
morphine, hydromorphone, fentanyl
Common partial agonist opioid (moderate pain control)
buprenorphine
Common agonist-antagonist opioids (mild to moderate pain)
butorphanol
common antagonist for opioids
naloxone
Opioids to know
-morphine
-butorphanol
-buprenorphine
-hydromorphone
-fentanyl
-tramadol
Neuroleptanalgesics
a profound state of sedation and analgesia induced by simultaneous administration of an opioid and a tranquilizer
Anticonvulsants are drugs used to control
seizures
Anticonvulsants
-Benzodiazepines (diazepam and midazolam (short term))
-Phenobarbital (long term)
-Bromide
-Gabapentin (added for refractory seizures)
-Zonisamide
Phenobarbital used for ___ and animal well have/need
control of epilepsy; PU/PD, sedation, therapeutic drug monitoring, liver monitoring
Potassium bromide used as an ____ . long half life, given as loading dose
adjunct for refractory seizures,
General anesthetics affect the CNS, produce loss of
sensation with partial or complete loss of consciousness
Local anesthetics block
nerve transmission in the area of application with no loss of consciousness
Local anesthetics end in
“caine”
Barbiturates used mainly as _____; side effects include:
anticonvulsants and euthanasia solutions ; potent cardiovascular and respiratory depressions
Barbiturates examples
phenobarbital, pentobarbital
Dissociatives belong to the __ family
cyclohexamine
Dissociative anesthetics
Ketamine and Tiletamine
skeletal muscle relaxant used in combination with an anesthetic drug to induce general anesthesia in horses (used alone it is not an anesthetic)
Guaifenesin
General anesthetic- ultra-short acting, nonbarbiturate anesthetic that produces rapid and smooth induction when given IV (last 2-5 minutes) side effects include cardiac arrhythmias and apnea
propofol
Inhalant general anesthetics are used to produce _ _
general anesthesia
Inhalant general anesthetic- noninflammatory, causes rapid induction of anesthesia and short recoveries following procedures, side effects include respiratory depression and malignant hyperthermia
Isoflurane
Inhalant general anesthetics- non-inflammable, main isomer of isoflurane, rapid induction and recoveries, produces fewer cardiovascular effects, low tissue solubility making it rapidly eliminated
Sevoflurane
CNS stimulants reverse
CNS depression caused by CNS depressants
CNS stimulant that stimulates brainstem to increase respiration in animals with apnea or bradypnea; commonly used when animals have C-sections
Doxapram
All drugs used in psychotherapy are thought to produce their effect through
alteration of NT activity in brain
Drugs used in Behavioral Pharmacology
-Acetylcholine
-Dopamine
-NE
-Serotonin
-GABA
Monoamine Oxidase-B inhibitors increase _ levels
dopamine
Tricyclics prevent reuptake of _ and _
NE and serotonin
Euthanasia solutions usually contain _
pentobarbital
