Exam 3 Flashcards
what is pain?
an unpleasant sensory and emotional experience associated with actual or potential tissue damage or described in terms of such damage
what is nociception?
the neural process of encoding noxious stimuli
Name and describe the neural steps in processing of pain signals
transduction: noxious stimuli are converted to electrical signals in sensory nerve endings
transmission: neural events which relay the information from the periphery to the cortex
modulation: the nervous system can selectively inhibit the transmission of pain signals
perception: subjective interpretation by the cortex of the noxious stimulus (sensory and affective component)
the therapeutic goal of pain treatment is to
eliminate abnormal pain without interfering with normal protective pain
activation of nociceptors sends signals to many parts of the brain including:
anterior cingulate cortex, basal ganglia, hypothalamus, parabranchial nucleus of dorsolateral pons, posterior cingulate cortex, posterior parietal complex, supplementary motor area
the ascending pain system…
transmits information from nerve endings to the brain
the descending pain system….
allows the brain to modulate incoming information by sending projections down to the spinal cord
afferent fibers synapse in the —- and project —- separate pathways to the —-. One pathway is for —— —— aspects of pain and the other is for the —– aspects of pain
dorsal horn, up, brain, sensory discriminative, emotional
Name and describe the three categories of primary afferent fibers
Alpha beta fibers: myelinated non-nociceptive, very fast conduction, convey light touch/vibration, may become nociceptive after nerve injury
Alpha delta fibers: myelinated nociceptors, fast conduction, convey fast pricking pain, cold, thermal
Nociceptive C fibers: unmyelinated nociceptors, slow conduction, convey slow burning and aching pain, polymodal (high threshold mechanical, thermal, cold)
first pain is characterized by —- fibers while second pain is characterized by — fibers
A delta, C fibers
Fibers are typically referred to by the stimuli they respond to an example would be CPM, CM, CH which stand for ——
Polymodal, mechano, heat
TRP channels are —– in nociceptors and other sensory neurons
thermosensors
what is allodynia?
perception of pain from a normally non-painful stimulus
what is hyperalgesia?
exaggerated perception of pain from a normally painful stimulus
today —- and other —– are commonly used for —— pain while —- and —- are gold standard for moderate to severe pain
aspirin, NSAIDS, inflammation-induced, morphine, opioid
what are opioids?
peptides that bind to the same postsynaptic receptors as bioactive opium extracts
name the 3 groups of endogenous opioid receptor ligands
endorphins (endogenous morphine), enkephalins, dynorphins
name and describe the 3 major GPCRs that bind opioid peptides
mu opioid receptors: major analgesic target, also responsible for addictive effects, bind endorphins
delta opioid receptors: minor analgesic target, bind enkephalins
kappa opioid receptors: possible pro-nociceptive effect, cause dysphoria, bind dynorphin
Describe how opioids are highly effective analgesics presynaptically and postsynaptically
presynaptic: block calcium influx, open potassium channels (potassium efflux), decreases excitatory neurotransmitter release
postsynaptic: open potassium channels, hyper polarize 2 order neuron, inhibit action potential generation
describe analgesics for acute pain
local anesthetics, blockage of voltage gated sodium channels, drugs end with Caine, side effects include respiratory depression, cardiovascular problems, seizures
acetaminophen: cox inhibition but different than NSAIDs, side effects kidney and liver failure
NSAIDs: inhibits COX1 & COX2, ends with in/en/ac/ib, side effects include ulcers, kidney failures, prolonged bleeding, reye syndrome
describe analgesics for acute-chronic pain
opioids: reduce activity of pain fibers and increase central modulation of pain, end with Eine/yl/one, side effect include vomiting, constipation, confusion, respiratory depression, abuse
Name and describe centrally acting analgesics
opioids, cannabinoids (sim to opioids in analgesic profile)
alpha 2 adrenergic agonists: used as opioid holiday during chronic opioid therapy
NE reuptake inhibitors: increase NE and activate alpha 2
selective ion channel blockers: Calcium and sodium ion channels modulate neuronal excitation and antagonists specific for channels subtypes may have few side effects
anxiolytic drugs can also treat —– and in high doses can cause —- and ——- from —— and ——-
insomnia, unconsciousness, death, respiratory , cardiavascular depression
acute anxiety can be treated by
benzodiazepines
panic disorder can be treated by
SSRI/SNRI and behavioral therapy
OCD can be treated by
long term antidepressants along with behavioral therapy
PTSD can be treated by
behavioral therapy, ketamine, prazosin, propranolol
Name and describe the classification of anxiolytic and hypnotic drugs
benzos: most important class used for treating anxiety and insomnia
5HT1A receptor agonists: showing anxiolytic activity with little sedation
barbiturates: now obsolete but still occasionally prescribed
Beta adrenoreceptor antagonists: mainly to reduce physical symptoms of anxiety such as tremors and palpitations
—— was the 1st benzodiazepine and some benzodiazepines like —– show anticonvulsant activity with less marked sedative effects
chlordiazepoxide, clonazepam
describe the mechanism of action for benzodiazepines
they act selectively on GABA A receptors
enhance the response to GABA by facilitating the opening of GABA-activated Cl- ion channels
do not affect receptors for other amino acids such as glycine or glutamate
name the main effects of benzodiazepines
-reduction of anxiety and aggression
-sedation and induction of sleep
-reduction of muscle tone and coordination
-anticonvulsant activity
-anterograde amnesia
with the exception of —— benzodiazepines do not have antidepressant effects
alprazolam
Benzodiazepines in acute overdose are —— dangerous than other anxiolytic drugs
less
in overdose, benzodiazepines cause
prolonged sleep without serious depression of respiration or cardiovascular function
what are the main side effects of benzodiazepines?
drowsiness, confusion, amnesia, impaired coordination
tolerance of benzodiazepines appears to represent a change at the —– level
receptor
stopping benzodiazepine treatment after weeks or months causes —–, —–, and —–
increase in symptoms of anxiety, tremor, dizziness
withdrawal of benzodiazepines after chronic administration causes physical symptoms similar to those that follow —- withdrawal, namely —–, —-, —–, and sometimes ——
opioid, nervousness, tremor, loss of appetite, convulsions
benzodiazepine clinical uses include
treatment of anxiety, status epilepticus, muscle spasm alcohol withdrawal, preoperative sedation, light anesthesia, anterograde amnesia
describe the pharmacokinetics of benzodiazepines
given orally, intravenously, intramuscularly
metabolized in liver and excreted in urine
benzodiazepines can have interactions with
alcohol and other CNS depressants by having an additive effect
SSRIs and SNRIs often have —— efficacy and —- incidence of side effects compared to —- and —–
greater, lower, benzos, barbituates