Neuropathic Pain Flashcards
what does gabapentin targget
calcium channel (central sensitization)
what do TCAs target
NE/serotonin receptor
disinhibition
what so SNRIs target
NE, serotonin (disinhibition)
what does lidocaine target
sodium channels (peripheral)
efficacy of neuropathic pain meds
not a lot of eveidednce
very few comparative trials suggest similarity
dont look at the NNT poor studies behind them
can consider them all the same and pick based on the patient
should we use opioids
very low eficacy and lots of dependence and abuse so no
is tramadol an exception
besides opioid receptor agonist its also inhibits NE and serotonin reuptake
lower abuse potential but still not that great
what do we know about functioning
insufficient evidence regarding quality of life but we can assess this in our patients
TCA side effects
constipation, dry mouth
weight gain
orthostatic hypotension
sedation
TCA cautions
elderly, dementia, glaucoma, urinary retention, cardiac disease
gabapentin and pregabalin SE
dizzy
sedation
peripheral edema
gabapentin cautions
elderly
edema
fall risk
abuse potential
SNRI SE
nausea - goes away with time
increased BP
dizziness
SNRI cautions
hypertension
biploar
tramadol SE
nausea
constipation
sedation
dizziness
tramadol cautions
opioid dependence
addiction risk
seizure risk
3 options worth a trial but just warn patient that most experience side effects
TCA
gabapentin
SNRI
non pharms
meditation psychosocial CBT music exercise? - good for other stuff heat and ice
dosing trial for TCA
start 10-25 HS to 50-100HS
max 150
dosing trial for gabepentin
start at 300mg/day then 300-900TID
max 1200TID - max dose just see a plateau and increase in SE
dosing trial for pregabalin
start 75 BID then 150-300 BID
dosing trial for duloxetine
start 30 mg then go up to 60mg
dosing trial for venlafaine
37.5daily
then up to 150-225 daily
how long is an adequate trial of meds
once reach the low end of the usual effective dose then 2-4 weeks
onset for pain meds
1 week
ways to incease dose
fast: increase 50-100% every 3 days
slow: increase 50-100% every week
why do we start low and go slow
no rush
not worth risking harm to the patient
side effects may result in a loss of a viable option
higher doses have a low likelihood of resulting in greater benefit
drugs to use if patient has depression or anxiety
TCA - but we tend not to use doses as high as in depression
SNRI
drugs to use if patient has insomnia
gabapentin
TcA
drug to use if patient has osteoarthritis
duloxetine
tramadol
drug to use if patient has migraines
TCA
monitoring timeline
1 week to se how their doing, side effects
2-4 weeks for efficacy: pain level and functioning
if patient sees no benefit try
increase dose if not at upper dose
it at upper dose stop and switch
if patient experiencing some benfit from med try
continue and maybe increase the dose or add another agent
if side effects not tolerable try
if there was a benefit at a lower dose decrease the dose and add another agent
or stop and switch
if med tolerable and effective reassess for ongoing need in
3 months
should we use combination therapy
not a lot of evidence
may be beneficial to have ttwo diff moa?
which two do we absolutely not combine
gabapentin + opioid
NNT = NNH
lidocaine advantages
immediate onset
min systemic absorption
capsaicin recommendation
doesnt work
burning just cuases a distraction
topical option if very resistant to all treatments
ketamine
patient counseling points
benefit
onset
side effects
cost/coverage
