Neuro: Drugs for Pain Flashcards
What does tissue damage initiate the release of?
Prostaglandins (PGE2),
Bradykinin,
Histamine
What causes secondary hyperalgesia?
Glutamate stimulation of spinal NMDA receptors
MOA of aspirin
irreversible inhibits COX-1 and COX-2
Clinical use for aspirin?
Immediate release as analgesic, antipyretic, and anti-inflammatory
Extended-release: reduce stroke
Off label uses for aspirin?
Colon cancer, to prevent atherosclerosis
Adverse effects of aspirin?
ulcer and risks of bleeding
Increase serum creatinine
-loss off PG vasodilation of afferent arteriole
What is nociceptive pain?
perception of input from a nociceptor, which is a nerve fiber
What is neuropathic pain?
Abnormal neural activity secondary to disease, injury, or dysfunction of the nervous system
MOA of ibuprofen and naproxen
reversible inhibits COX-1 and COX-2
Black box warning in all NSAIDs
Increase risk of MI and stroke
Increase risk of bleeding
Who should avoid NSAIDs
Pregnant women (can lead to renal dysfunction and close ductus arteriosus)
CABG pts
Celecoxib MOA
selective reversible COX-2 inhibitor
Adverse effects of celecoxib?
Thrombotic events (from sketchy)
What conditions is aspirin especially useful for?
Chronic pain conditions, such as rheumatoid arthritis
What should you do when prescribing nonasparin NSAIDs
use lowest possible dose for shortest time due to increase risk of MI and stroke
Does celecoxib increase risk of bleeds?
No, does not inhibit platelets
-does increase risk for thrombosis though
MOA of acetaminophen
TRPV1 and TRPA activation (possibly?)
Clinical applications of acetaminophen
temporary relief for aches and pains, and headache
-only for mild to moderate pains
Black box warning of acetaminophen?
Risk of medication errors and overdose–>hepatotoxicity with acute liver failure
Does acetaminophen suppress inflammation?
Nope, only pain and fever
Is acetaminophen associated with the GI and anti-platelet side effects of NSAIDs?
No, does not inhibit COX1/2
How do you treat acetaminophen overdose?
N-acetylcystine can replenish reduced glutathione stores
MOA of morphine
binds opiod receptors in brain
Black box waring for morphine
respiratory and CNS depression, especially with other drugs
What are three firstline drug classes for neuropathic pain?
- α2δ Ca channels blockers (pregabalin, gabapentin)
- SNRIs (duloxetine)
- TCAs (amitriptyline)
MOA of amitriptyline
tricyclic antidepressant
-increases NE and 5-HT in cleft
Black box warning for amitriptyline
increase risk of suicidal thinking and behavior in children, adolescents, and young adults
MOA of duloxetine
Potent Serotonin and NE Reuptake Inhibitor
Great for depression and neuropathic pain
Black box warning for duloxetine
increases risk of suicidal thoughts and behaviors
MOA of pregabalin
α2δ Ca voltage gated channels blockers (in CNS)
Uses for pregabalin and gabapentin
Neuropathic pain and focal (partial) seizures
What is gabapentin used for most of the time (80%)? off-label
Neuropathic pain
-post-herpetic neuralgia, diabetic neuropathic, fibromyalgia
Second-line treatment for neuropathic pain?
- Valproate
- Opiods
- Tramadol
MOA of tramadol
partial agonist at μ opiate receptors
-also blocks NE and 5HT reuptake
Black box warnings for tramadol
overdose, addiction, abuse
CytP450 interaction
Withdrawls
Respiratory and CNS depression
Adverse effects of tramadol
sedation, dizziness, headache, dry mouth, and constipation
MOA of ketamine
noncompetitive NMDA receptor antagonist
Clinical use of ketamine
analgesia, acute and chronic pain
-including neuropathic
Dexamedetomidine MOA
selective alpha2-adrenoreceptor agonist
-sedative and anesthetic
Clinical applications of dexamedetomidine
Short term sedation of ill patients who are intubated
sedation prior to procedures
Clinical use of clonidine
a2 agonist for HTN and pain
MOA of ziconotide
N-type voltage gate Ca channel
Black box warning for ziconotide
severe psychological impairment and has a high risk of patient harm (?)
Clinical applications of ziconotide
chronic severe pain, intrathecally, for those who are refractory to other treatments
MOA of capsaicin and camphor
Topical TRPV1 “hot”
MOA of menthol
Topical TRPM8 “cold”
MOA of sumatriptan
selective 5-HT1B/D agonsit
Clinical applications of the triptans
migraines
MOA of lasmiditan
highly selective 5-HT1F receptor
MOA of ubrogepant
calcitonin gene-related peptide receptor antagonist
MOA of dihydroergotamine (DHE)
ergot alkaloid agonist for 5-HT receptors
What drugs is dihydroergotamine contraindicated with?
CYP3A4 inhibitors
-azoles, macolides
Leads to vasospasm and cerebral ischemia
