Pain and NSAIDS Flashcards
allodynia vs. hyperalgesia
hyperalgesia: increase in magntitude and duration of painful stimuli
allodynia: previously non-painful stimulus is now painful
primary vs secondary hyperalgesia
primary: release of factors near site of injury increase the pain sensitivity there
secondary: increased sensitivity in surrounding, undamaged tissue
What prostaglandin is found at sites of inflammation and tissue injury? What else does it do?
PGE2. Also acts centrally to enhance pain processing
What is the target of NSAIDs and what does this do?
cyclooxygenase is the primary target.
this is important for converting arachidonic acid to prostaglandins. prostaglandins needed to make other prostaglandins or thromboxane
What are the differences in COX enzymes?
COX1 constituitively expressed for homeostatic purposes
COX 2 is a regulated PF for acute responses
What would I see with aspirin overdose?
vomiting, tinnitus, metabolic acidosis, and respiratory depression.
What is acetaminophen? Important things to know.
analgesic/antipyretic with little antiinflammatory and no anti-platelet effect
hepatoxicity seen with overdoses due to active metabolite. Particularly profound effect when combined with alcohol.
What is the side effect profile of celecoxib?
fewer major GI complications
like with traditional NSAIDs, still see renal issues/edema
may raise risk of cardiac factors
What do opioid receptors do, chemically?
inhibitory. ihibit adenyl cyclase, stimulate potassium channel activity and inhibit calcium channel activity. chronic stim leads to upregulation of cAMP pathway. it inhibits neurotransmitter release and acts as a neurotransmitter itself
What are side effects of opiods that I should know
respiratory depression- occurs even at doses too small to disturb consiousness. MAJOR SOURCE OF DEATH.
may suppress cough if closely related to morphine
often cause nausea and vomiting by effects in the chemoreceptor trigger zone
postural hypotension
CONSTIPATION
fentanyl
fat soluable; fast onset, short duration. crosses BBB easily. be careful with fentanyl patches- they take a few days to work
remifentanyl
newest potent opioid. ultrashort action- very fragile. immediately hydrolyzed. allows us to rapidly titrate the opiod level.
normeperidine
used to prevent shivering in post-op period, but otherwise use with caution- metabolite has a long half life and can cause seizures
methadone
long lasting mu agonist. potent NMDA receptor antagonist. good long term med for chronic pain. avoids euphoria and withdrawal bc of long half life
codeine
prodrug that requires CYP22D6- many ppl don’t make this enzyme
hydrochodone
aka vicodin
also a prodrug that requires enzyme CYP22D6. often mixed with tylenol- be careful of tylenol toxicity
mu antagonists
naloxone and naltrexone
