Pain management Flashcards
Gabapentin and Pregabalin
mechanism
side effects
Binds to α2δ subunit of VSCC - may act to ↓ release of excitatory NT glutamate in pain pathways
Sedation-ataxia-dizziness
Generally free from drug-drug interactions
Risk of abuse with pregabalin-CV controlled substance
Antidepressants
TCADs (amitryptiline, nortriptyline)
SNRIs (Venlafaxine, duloxetine)
adverse effect
block NE reuptake but diff from antidepressant
enhance pain inhib path
effective at low dose
adverse = sedation and anticholinergic side effects
HTN, anxiety, more rapid withdrawal with TCADs
Lidocaine
method
adverse
block VSSC to decr neural transmission
topical
adverse = hypersensitivity, lightheaded, dizziness, drowsiness
Ketamine
mechanism
side effect
glutamate antagonist at NMDA receptors in ascending pain path
used in chronic pain
HTN, arrhythmia, diplopia, n/v
antidepressant for low back pain and fibromyalgia
low back pain = TCAD
fibromyalgia = SNRI
NSAIDs, acetaminophen, COX-2 selective, aspirin
decr (periph/central/both) sensitization
indicated for
if pain localized to specific joints
decr both
indicated for mild to mod somatic soft tissue, strains, HA, osteoarthritis
topical NSAID
opioid analgesics used for
acute neuropath pain
neuropath cancer pain
episodic exacerbation of severe pain
moderate to severe
treatment of mild acute pain
treatment of moderate pain
treatment of severe pain
1) non-opioid +/- adjuvant analgesics
2) immediate release short acting opioids with slow titration + NSAIDs +/- adjuvant analgesia
3) immediate release short acting opioids with rapid titration + non-opioid +/- adjuvant analgesics (LAs) managed with multimodal analgesia
treatment of chronic persistent pain
non-opioid and adjuvant meds
the ___ opiods with have more rapid onset
more lipid soluble
most severe adverse effect of opioids
reverse with
respiratory depression due to decr in sensitivity of resp centers (prominent sedation before significant depression)
reverse with naloxone
manage pruritis from opioids following systemic vs neuraxial administrtation
systemic = antihistamines (diphenydramine)
neuraxial = opioid partial agnoist (nalbuphine)
How does NaHCO3 affect rate of LA onset of action
drives rxn to right to release H+ and incr rate of onset
benefits and side effects of local anesth
beenefits = opioid sparing action; decr DVTs, better cough, less constip
side effects = neurotox, hypotension, dizziness, drowsiness
differential nerve block
what is most impt?
which are smallest?
any dose of LA that causes loss of pain will cause loss of SNS vasoconstriction
size is most impt consideration
sensory pain and postgangl symp neurons smallest
cause loss of SNS vasoconstriction
Order of sensitivity to block with differntial nerve block
cold > warmth > touch
pressure > vibration > proprioception > motor
NSAIDs cox 2 inhib
oral route for ___
IV forms for?
side effects
esp COX-2 selective
oral = mild to mod pain IV = ketorolac and ibuprofen
side effect =
1) GI ulceration
2) incr bleeding
3) renal failure
4) COX-2 selective = incr thrombotic
Lowest GI risk of NSAIDs
Lowest cardio risk of NSAIDs
Lowest hepato risk
GI = cox1 inhib > cox2 inhib
lowest with ibuprofen
Cardio = cox2 inhib > cox1 inhib
lowest with naproxen
Hepato = ibuprofen
Clonidine
mechanism
route
side effects
mechanims = a2 adrenergic agonist on dorsal horn and LC cells
decr opioid requirements
route = epidural infusion
side effects = hypotension, bradycardia, XS sedation, rebound HTN upon withdrawal
Ketamine
mech
routes
side effects
mech = block NMDA receptors, decr development of tolerance to long-term opioid use
routes = IV and intranasal
side effect = suboptimal tolerability limits usefulness
ketamine vs memantine
memantine = low affinity non-competitive antag at Mg2+ and block effects of tonic XS glutamate
phasic burst of glutamate and depol will remove the low-affinity memantine for normal neurotransmission
NSAIDS most efficacious for ?
COX2 inhib most efficacious for?
opioids most efficacious for?
Anticonvulsants most efficacious for?
Tricyclic most efficacious for?
NSAIDs = tissue injury
COX2 inhib = tissue injury
opioids = acute stim = tissue injury
anticonvulsants = nerve injury
tricyclic = nerve injury
