Barker Flashcards
chronic pain is defined as _____
lasting greater than 3 months
types of chronic pain
nociceptive
neuropathic
visceral
mixed
what is nociceptive pain?
tissue
- arthritis
(inflammatory)
types of neuropathic pain
central
peripheral
central neuropathic pain examples
stroke
MS
spinal cord injury
migraine
peripheral neuropathic pain examples
infection (post herpes)
diabetic neuropathy
what is visceral pain?
internal organs
-pancreatitis
-IBS
(inflammatory)
mixed pain examples
low back
cancer
2 functions of pain
warning system
aiding in repair
inflammatory pain description
throbbing, pulsating
neuropathic pain description
tingling, burning, shooting, stabbing
visceral pain description
squeezing
peripheral receptors and channels in pain
temperature sensitive
acid sensitive
chemical irritant sensitive
types of temperature sensitive channels/receptors
TRP
TRPV - heat
TRPM - cold
acid sensitive channels are activated how and conduct what
ASIC
activated by H+ protons
conduct Na+
chemical irritant sensitive channels release what
histamine
bradykinin
what is the reflex arc
bypasses CNS and goes from periphery to spinal cord to muscle (ex. touching something hot)
which channel very important for action potential traveling to spinal cord?
Na 1.8
receptors at spinal cord
NMDA
AMPA
mGluR
three pain fibers
alpha beta
alpha delta
C fibers
alpha beta pain fibers pain signal transduced and speed
non-noxious (touch, pressure)
innervate
faster
alpha delta pain fibers pain signal transduced, speed, myelination
pain, cold
myelinated
fast
“first pain”
c fibers pain signal, speed, myelination
pain, temp, touch, pressure, itch
unmyelinated
slow
PROLONGED pain
“second pain” dull / aching
what is peripheral sensitization?
repeated stimuli reduces firing threshold
increased expression of pain receptors (more sensitive to the touch)
what does substance P do?
vasodilation
degranulation mast cells
histamine release
inflammation and prostaglandins
which neuropeptide is released when there is injury?
substance P
what happens in neuropathic pain sensitization when we have more afferent activity
overexpression Na channels
- enhanced excitability
- generation action potentials
what happens with post-synaptic receptors more activated and AMPA / NMDA
increased AMPA and NMDA expression and sensitivity
how do we get more AMPA and NMDA expression?
increased PLC and PKC
where is there high expression of opiod receptors in brain?
descending pathway of brain stem
cortex does what with pain
identifies location of pain
amygdyla does what with pain
processing of the feeling, anxiety, emotion
prefrontal cortex does what with pain
plans action and decisions
determines what we will do as a result of pain
nucleus accumbens does what with pain
release dopamine and serotonin
what is an opiate
naturally occuring, plant derived
phenanthrenes SAR
three rings
3 position ester/ether does what
decreased potency (codeine)
6 position does what
increases activity (hydrocodone from codeine)
nitrogen substitution does what
gives antagonist / partial agonist activity
(buprenorphine or naloxone)
how are endogenous peptides activated
large proteins cleaved into opioid subtype selective peptides
POMC protein cleaved to what peptide that codes what receptor
beta endorphin > mu opiod
preproenkephalin cleaved to what peptides that code what receptor
leu- enkephalin > delta
met - enkephalin > mu and delta
preprodynorphin cleaved to what peptides and code what receptos
dynoprhin > kappa
opiod receptors are _____ and do what
GPCR
Gi - inhibit cAMP
opiod receptors do what to channels
open GIRK K+ channels
close Ca+ channels
(decrease firing)
endogenous opiod of Mu
endorphin
endogenous opiod of Kappa
dynorphin
endogenous opiod of delta
enkephalin
endogenous opiod of nociceptin
nociceptin
sigma receptors are what
not an an opioid receptor
what do opiod receptors do presynaptically?
inhibit calcium channel, decrease in neurotransmitter release
what do opiod receptors do postsynaptically?
open GIRK channel
efflux of K+ making more negative and hyperpolarization
what is a component of runners high in mu opioid receptors?
beta- endorphins
use of mu opiod therapeutically
analgesia (not chronic)
sedation
anti tussive
opiod induced side effects are ____ target
on target
on target side effects of mu opiod receptors
respiratory depression
constipation
pruritus (itch)
urinary retention
N/V
miosis
activation of kappa opiod receptor does what
dysphoric and aversive, negative effects
reduce dopamine release
which opiod receptor can counteract the effects of mu
kappa
delta opiod receptors have a role in what
protection
stroke/ischemia/hypoxia
reduce anxiety, depression
delta receptors as drugs ?
NO FDA approved ones
opiod reward centers
ventral tegmental
nucleus accumbens
how do depressants cause dopamine release with opioid binding
opiod binds mu
Gi - decrease neurotransmitter release
less GABA to activate GABA A
less dopamine inhibition
more dopamine release
more dopamine receptor activation
what is morphines bioavailability
25%
morphine cyps
2D6
3A4
which opiods are prodrugs
heroin
codeine
tramadol
which do not have active metabolites
fentanyl
methadone
codeines active metabolites
hydrocodone
morphine
heroin active metabolite
morphine
tramadol active metabolite
o- desmethyltramadol
what does CYP3A4 do to opioids
converts to nor, inactive
what does CYP2D6 do to opioids
activates
extensive metabolizers have ___ concentrations of morphine
50% higher, more side effects
poor metabolizers effects from codeine
none
what drugs are broken down by plasma esterases?
sufentanil
remifentanil
alfentanil
(esterase linkages)
which opioid has SNRI properties
tramadol
which opioid renal excreted
meperidine
not recomended
meperidine toxic metabolite
normeperidine
CYP3A4
which opiod blocks NMDA receptors
methadone
which opioid QTC?
methadone
pentazocine receptors
kappa agonist
partial agonist/antagonist at mu
butorphanol receptors
kappa agonist
partial agonist/antagonist at mu
nalbuphine receptors
full agonist kappa
antagonist at mu
buprenorphine receptors
partial mu agonist
weak kappa agonist
weak delta antagonist
senna causes what
colonic contraction
methadone: speed, PK
slow acting
accumulation
full agonist
buprenorphine is a ____
partial agonist
subutex has ____
abuse potential
naltrexone is a _____
antagonist
naltrexone bioavailability
decent oral
best if pt has been drug free for 1 month or more
causes withdrawal
naloxone bioavailability
limited oral bioavailability
short half life
non-pharm treatment of neonatal abstinence syndrome
swaddling
hypercaloric formula
feedings frequently
redhydration
best pharm treatment for withdrawal baby
buprenorphine and morphine
could do methadone or clonidine too
examples of eicosanoids
arachidonic acid metabolites
prostaglandins (red, heat, pain)
thromboxanes
leukotrienes (swelling)
cytokines (pain)
COX-1 protects what
GI expression
which drug irreversibly inhibits COX enzymes
aspirin
which drugs inhibit leukotrine synthesis
indomethacin
diclofenac
can aspirin have tolerance to analgesia
no
risk in aspirin for children
Reyes Syndrome
absorption of aspirin and salicylates
rapid
aspirin and salicylate half life
ASA 15 min
salicylate 6-20 hours
increased excretion of ASA / salicylate with what
increased urinary pH
(from like bicarb)
effects of aspirin poisioning
vertigo
tinnitus
respiratory alkalosis (hyperventilation)
metabolic acidosis (low blood pH)
treatment of aspirin / salicylate poisioning
reduce salicylate load
increase urinary excretion
dextrose and sodium bicarb
ibuprofen is a _____ COX inhibitor
reversible
half life ibuprofen
2 hr
half life naproxen
14 hr
diclofenac risk
peptic ulcer and renal dysfunction
what is misoprostal
PGE1 analog, used with diclofenac
indomethacin is a ______ inhibitor of PG biosynthesis
potent reversible inhib
indomethacin risk
lots of severe side effects long term
what is the less toxic derivative of indomethacin
sulindac
meloxicam COX selectivity
at low doses COX 2 selective
meloxicam halflife
20 hours
piroxicam half life
57 hours
adverse effects of NSAIDS
renal issues with peripheral edema!
risk of bleeding
inhibition of uterine motility
GI ulceration
acetaminophen is effective as what
analgesic
antipyretic
advantage of tylenol over NSAIDs
no GI toxicity
disadvantage of tylenol over NSAIDs
hepatic necrosis
greater risk renal toxicity
risk with alcohol and Tylenol
hepatic necrosis
increase in toxic acetaminophen metabolites (NAPQI)
how does hepatic necrosis happen
increase in NAPQI with depleted GSH to break it down
COX 2 selective agents benefit and harm
benefit - reduced GI bleed / ulcer
risk - blood clot, CV issues`
which NSAIDs are COX 2 selective
celecoxib
diclofenac
meloxicam
NSAID contraindications
CKD
peptic ulcer disease
hx / GI bleed
NSAIDs risks
cardiovascular risk
interfere with bone healing
asthma exacerbations
local anesthetics are ____ blockers
sodium channel
-caine
which sodium channel blocker has high allergy risk
benzocaine
esters
which drugs are sodium channel blockers?
local anesthetics
anticonvulsants: lamotrigine, carbemazepine, ozcarba
tricyclic antidepressants: amitriptyline
which anticonvulsant off label peripheral neuropathy
lamotrigine
how can SNRIs provide analgesia
alpha 2 receptors in spinal cord
duloxetine pain uses
diabetic pain
fybromyalgia
peripheral neuropathy
velafaxine off label use pain
diabeteic neuropathic pain
SNRI without sodium channel functionality?
milnacipran for fibromyalgia
calcium channel blockers as analgesics
gabapentin
pregabalin
gabapentin and pregabalin selectivity
alpha 2 delta
Cav 1, 2 selective
half life of pregabalin and gabapentin
4-8 hours
metabolism and interactions of gabapentin and pregabalin
no drug drug interactions
not metabolized
stimulant drugs
coacaine
amphetamines
meth
bath salt
ecstasy
nicotine
depressant drugs
alcohol
GHB
cannabis
opioids
inhalants
psychedlic drugs
LSD
psilocybin
PCP
mescaline
ketamine
what does schedule 1 mean
no medical use
schedule 1 drugs
marijuana
THC
LSD
heroin
schedule II drugs
cocaine
PCP
morphine
hydrocodone/oxycodone
what does schedule II mean?
high abuse potential
what does schedule III mean?
moderate abuse
schedule III drugs
ketmaine
buprenorphine
marinol (THC in capsule)
what does schedule IV mean
low abuse potential
schedule IV drug example
benzos
which drugs act indirectly on GPCRs
cocaine
amphetamine
MDMA
ecstacy
alcohol
how does cocaine and amphetamiens work
dopamine transporter
release neurotransmitters
which drugs work on ion channels
nicotine
PCP
ketamine
benzos
barbs
how does nicotine work
achetylcholine receptor agonist
how does PCP and ketamine work
antagonist at NMDA receptors
how do benzos and barbiturates work
positive allosteric modulators at GABA A receptors
which drugs work directly on GPCRs
opiods
LSD
caffeine
nucleus accumbens does what
pleasure / valuation
VTA does what in brain
source of dopamine
dopamine hypothesis of addiction
dopamine assigns value to reward
value gives incentive salience
dopamine doesn’t encode liking but does what
makes reward predictions
rewarding substances do what to glutamate AMPA receptors
increase them
mild
moderate
severe
substance abuse rating
mild - 2-3
moderate - 4-5
severe - 6+
physical dependence is what
tolerance
body needs drug
physical withdrawal symptoms
goose bumps - cold turkey
muscle spasms - kicking habit
sweating
tremors
N/V
dangerous withdrawal symptoms
grand mal seizures
delirium tremens (DTs)
psychological dependence is what
addition
compulsive need /craving
positive reinforcement
user feels pleasure
negative reinforcement
user escapes negative or painful event