Pain Deck 2 Flashcards
Peripheral
Sensitization
Drugs
Local Anesthetics Topical Analgesics Anticonvulsants Tricyclic Antidepressants Opioids
Descending Modulation
Drugs
Anticonvulsants
Opioids
Tricyclic/SNRI Antidepressants
Central Sensitization
Drugs
Anticonvulsants
Opioids
NMDA-Receptor Antagonists
Tricyclic/SNRI Antidepressants
NSAID examples
Aspirin Nonselective Cox 1and 2 inhibitors (ibuprofen, naproxyn) Selective cox-2 inhibitors (celebrex) Ketorolac (Toradol)
NSAID MOA
Block prostaglandin synthesis
Analgesia, antipyretic, anti-inflammatory actions
Toradol is used on an outpatient bases for
migraine
prostaglandins do what
reduce pain and fever
reduce inflmation
they also protect the stomach and promting clotting. So anything that works against these will cause GI upset and bleedign
ASA is an
antiplatelet
IBU can be taken every __ versus naproxin which is ___
6 to 8
12
NSAID pharmacokinetics
Biotransformed in the liver
Small amount excreted renally
NSAID side effects
Side effects: GI, renal, CV ( BP or HF)
Risk factors for NSAID ADR
Alcohol intake Age > 60 years Female gender Duration of treatment Type of NSAID use Multiple NSAID use Corticosteroid use Duration of treatment History of PUD Increased dosage History of PUD Comorbid CV condition
NSAIDs Contraindications
PUD, GI or other bleeding disorders, Hyperuricemia,
Impaired renal or hepatic function, Vitamin D
deficiency, Cancer, Pregnancy and lactation
Asthma-ASA-Nasal polyps triad
NSAID Lab considerations
LFTs, salicylate level, hct, PT and INR
False – urine glucose tests (Clinitest, Tes-Tape)
HF and Hypertension can be worsened by
NSAID
Acetaminophen MOA
Prostaglandin and Cox inhibition in CNS, no peripheral
action
Mild Analgesia, antipyretic, no anti-inflammatory
Acetaminophen PHarmacokinetics
Metabolized liver
Acetaminophen SE
Nephropathy , liver injury
Limit 3-4G per day*
The following opioids are available as combination
products with acetaminophen, aspirin, or ibuprofen
Codeine; hydrocodone; oxycodone; propoxyphene
acetaminophen has a direct
effect on hypothalmus
opioid combination are typically used for
Moderate episodic (PRN) pain
Breakthrough pain in addition to a long-acting opioid
opioids never use more than
one combination product at any one time
hydrocodone and oxycodone are more potent
than ____ , which is more potent than
_____, which some studies suggest is
equipotent to aspirin
codeine
propoxphene
there is little difference between hydrocodone
products and
oxycodone products in terms of
potency
Adjuvants
Non-pharmacologic Topicals Tylenol NSAIDS, Celecoxib, steroids Anticonvulsants Antidepressants Antiarrhythmics
Tramadol - Indications
mild to moderate pain
Tramadol MOA
entrally acting synthetic pain reliever
Action similar to morphine
Max dose 300mg/d
Not recommended for acute use for >5d
Tramadol SE
Side Effects
Increased falls in the elderly?
May be habit forming
Tramadol dont
Don’t stop abruptly, taper off
Agents to treat acute pain - Adjuncts
Preemptive analgesia NMDA receptor agonists Alpha-2 adrenerg g ic a onists Local anesthetics Anticonvulsants
Agents to treat chronic pain - Adjuncts
Anticonvulsants
Antidepressants
Preemptive Analgesia
After tissue injury or surgery:
Damage causes peripheral sensitization and central
sensitization
Treatment started before and is operational during a
surgical procedure
Antinociceptive treatment that reduces altered
sensory input
Research
preemptive analgesia decreases peripheral sensitization
Decrease in central sensitization controversial
Agents Shown to be of Pre-Emptive Benefit
Ketamine 0.25-1 mg/kg
Cox-2 I hibi * 2 Inhibitors*
Neurontin 300 mg
Local Anesthetics
Ketamine MOA
binds to phencyclidine site on the NMDA
receptor
Ketamine Use at
subanesthetic dose
Ketamine Current literature
Administer pre-incision and throughout the
perioperative period
Ketamine Other effects
Less PONV than control, no adverse psychic effects or
sedation
Local Anesthetics MOA
reversibly block impulse conduction along
nerve axons and other excitable membranes that
utilize sodium channels as the primary means of
action potential generation
Local Anestheits causes
reversible local anesthesia and a loss of
nociception
Esters
Tetracaine (Pontocaine)
Benzocaine
Cocaine
Procaine (Novacaine)
Amides
Lidocaine Mepivicaine Bupivicaine (Marcaine) Etidocaine(Duranest) Prilocaine
classification of local anesthetics
Esthers
Amides
Topical types
Topical
Emla
Tracheal lidocaine
Topicsal MOA
Peripheral nerve endings and major nerve trunks
Axillary, ankle blocks etc.
Topical administration
Epidural or subarachnoid
Alpha-2 Adrenergic Agonists examples
clonidine
dextemetomidine
Alpha 2 can be gven as an
infusion
Clinidine
Antihyptensive amd analgesic adjunct
No respiratory depression
Dextemetomidine (Precedex)
Central and peripheral effects More alpha-2 selective No respiratory depression May reduce HR and BP Potentiates effects of opioids, sedatives, anesthetics
Gabapentin (Neurontin) - in animal studies it
In animal studies it helps to prevent allodynia
Gabapentin (Neurontin) 0 used
Used preemptively, reduces anxiety in
Gabapentin (Neurontin) MOA
U k MOA Unknown MOA
Studies have suggested that it helps preemptively by
reducing wind up pain
Gabapentin (Neurontin) Dosine condierations
Dosing considerations: Renal dosing
Gabapentin (Neurontin) SE
dizziness, somnolence, edema
Pregabalin (Lyrica) is like
“Neurontin on steroids” Has greater analgesic effect on neuropathic pain in animal models Titrate up, taper down Reduces Opioid induced hyperalgesia
Pregabalin SE
Be careful with elderly
Can cause ataxia, drowsiness, depression, suicidal
Weight gain, peripheral edema,
