Week 3 Flashcards
How is nociceptive pain normally terminated?
By the healing and repair process
What is the key locus in the endogenous pain suppressant neural system (modulation)
Mesencehapilic Periacqueductal gray: enkephalin containing neurons.
It’s a multisynpatic pathway descending to dorsal horn of cord
What is another term for the endogenous opioid peptides?
Endorphins
Enkephalin is made out of ___ amino acids (___ and ___). Enkephalin binds to which to receptors?
5 amino acids
Methionine and leucine
Mu and delta
B-endorphin is made out of __ amino acids and binds to which two receptors?
91 amino acids
Binds to mu and delta
Other than affecting the pain pathway, what else do endorphins play a role in?
Stress
GI function
Endocrine systems
Affect the reward pathway (increase dopamine release through mesolimbic system)
Dynorphins A and B is made out of ___ amino acids and binds to which receptors? What i unique about dynorphins?
17 amino acids
Primarily K (kappa) receptors
Dynorphins are unique because they are dysphoric. This means that although it can block pain, it causes an unpleasant feeling, so there is no addiction potential
Endogenous opioid peptides (endorphins) play a key role in ___ feedback and other physiological processes
Inhibitory.
Negative feedback
Drugs that enhance the action of __ and __ in the CNS have antinociceptive effects
NE
5HT (serotonin)
Opioid analgesics act in ___ and ___
PAG (periaqueductal gray)
Dorsal horn
In the dorsal horn, opioid ___ the release of pain transmitters
Inhibit.
How can you pass out from intense pain?
Intense pain will pull blood from the brain to get the blood to the site of pain.
Neuropathic pain sensations may be __ or ___ but occur without the activation of ___ by actual or potential tissue damage.
Continuous
Periodic
Nociceptors
How can neuropathic pain occur?
May result from abnormal activity in nociceptive fibers that have been damaged, but after injury has healed
Or from abnormal activity in central pain pathways (solely occurs in brain without any input signal)
True or false.. neuropathic pain has a protective function and terminates with healing.
Both statements are false.
Name 5 examples of neuropathic pain
Phantom limb
Shingles
Fibromyalgia (9 points of pain)
Diabetes neuropathies
Trigeminal neuralgia
Where do diabetes neuropathies typically occur? Why? Describe the onset of the neuropathic pain.
Typically occurs in the extremities (feet) due to clogging of the microcirculation.
First their feet go numb. Then within weeks to months, they feel pain.
Describe the relationship of shingles with neuropathic pain.
Shingles lesions may cause neuropathic pain that doesn’t go away even after the lesion has healed.
If you treat shingles early and aggressively with antivirals you may avoid this.
What is another name for trigeminal neuralgia?
Tic douloureux
True or false… neuropathic pain may be resolved by NSAIDs or opioids.
NSAIDs do not resolve pain
Opioids inconsistently may resolve pain
True or false… some antidepressants, anticonvulsants, and corticosteroids cause some reduction of neuropathic pain.
True
Name one antidepressant that is used to treat neuropathic pain
Cymbalta
Name two anticonvulsants that may be used to treat neuropathic pain
Lyrica (specifically for fibromyalgia)
Gapapentin
What is a diagnostic tool to determine if the pt is experiencing neuropathic pain?
Functional MRI
Name 4 possible mechanisms for neuropathic pain
The peripheral sensitization process may persist rather than subside
Damaged nociceptive nerves may fire spontaneously
Prolonged input from hyperexcitable nociceptive fibers (learned)
Decreased activity of endogenous pain-suppressant neural system
What is the role of placebo with pain management?
Most likely caused by release of endorphins
Endogenous analgesia elicited by suggestion
Name 4 pain medications that act in the brain
Opioid narcotics
Glutamate
GABA
Antidepressants (5HT/NE)
Name two pain medications that act on descending modulation
Serotonin drugs
Neuropeptides
Name three pain medications that act on the dorsal horn of the spinal cord
Local anesthetic
Opioids
NSAIDs
Name two pain medications that act on nerves
Local anesthetic (can be used to locate area of neuropathic pain so it can be surgically treated)
Opioids
Name 5 pain medications that act in the tissues
Local anesthetic
NSAIDs
COX 1/2 inhibitors
Acetaminophen
Capsaicin
Where does arachidonic acid come from?
Membrane phospholipids
Which causes a higher incidence of stroke and heart attacks, COX-1 inhibitors or COX-2 inhibitors?
COX-2 inhibitors
This is because COX-2 inhibitors interfere with vasodilation
(COX-1 inhibition shouldnt cause cardiovascular problems)
What pain medications may cause stomach ulcers?
NSAIDs
COX-2 selective inhibitors do not
What pain medications may cause hepatic damage?
Acetaminophen
You should be careful with this drug when given to heavy alcohol drinkers and those with hepatitis.
What pain medication can cause bleeding-anticlotting?
COX-1 inhibitors
Aspirin (salicylates)
What pain medicaiton can cause cardiovascular problems?
COX-2 inhibitors
What pain medication can cause dependence/addiction?
Opioids
True or false… acetaminophen is an NSAID
False
True or false.. salicylates are NSAIDs
True
Salicylates inhibit COX-1 and COX-2
What dose of salicylates is recommended for the following…
Analgesia
Antiinflammation
Antipyretic (anti fever)
Analgesia - 600mg
Antiinflammation - 1gm
Antipyretic - 300-600mg
How long do salicylates typically last? What other drugs are often combined with it?
4 hours
Used for mild to moderate somatic pain
Often combined with caffeine, acetaminophen, or opioid
Name 4 side effects associated with salicylates
GI irritation and erosion
Reye’s syndrome in children (colds/flu)
Anti-clotting (last up to 1-2 weeks) (acetylation of the platelets is what prevents clotting, platelets need to be replenished)
Ringing in ears (tinnitus) - high dose
What is the dose for analgesia for ibuprofen?
400mg
What is the dose for anti-inflammation for ibuprofen?
800mg
What is the dose for antipyretic for ibuprofen? How long does it typically last?
400mg
4 hours
True or false… ibuprfen is used for mild to moderate pain relief and is often a little better than aspirin
True
What are the three main side effects of ibuprofen?
GI ulcers (less than aspirin)
Anti-clotting (less than aspirin)
Cardiovascular effects
Name two ibuprofen-like NSAIDs
Ketoprofen (orudis)
Naproxen (Naprosyn)
Ketoprofen is ___ potent than ibuprofen. What is a typical dose per capsule?
More
Lower doses (50mg/capsule)
Naproxen (naprosyn and aleve) have ___-lasting and ___-acting effects than ibuprofen
Longer lasting (about 8 hours)
Slower acting (takes about an hour. Ibuprofen is about 15 minutes)
(It’s a slow releasing drug making it longer for onset but longer lasting)
Celebrex is a __-selective antagonist, given by prescription only. It has ___ potency compared to ibuprofen. It lacks ___ and ___ action. And it has been linked with ___ side effects.
COX-2
The same
Lacks GI and anti-clotting action
Cardiovascular
Name three other NSAID agents that aren’t ibuprofen related.
Indomethacin
Meloxicam
Diflunisal (dolobid)
What is indomethacin?
Potent (between ibuprofen and opioid)
Nonselective NSAID
Used to treat severe rheumatoid arthritis and gout.
Not commonly used due to side effects
Meloxicam preferentially inhibits ___ over ___, meaning less ___ side effects but more ___ side effects.
COX-2
COX-1
GI
CV
Which NSAID agent is related to salicylates and is supposed to be good for bone pain because it concentrates in bony tissue?
Diflunisal (dolobid)
True or false… acetaminophen is an NSAID
False. It does not inhibit COX-1 or COX-2. But it may inhibit a COX-3 enzyme and/or serotonin
The chemical structure of acetaminophen looks similar to ___
Aspirin
Which drug is not a COX-1 or COX-2 inhibitor, has better analgesia for children than adults, has antipyretic properties, and seems to have a sedative effect in children?
Acetaminophen (Tylenol)
True or false… acetaminophen has better analgesia properties than aspirin.
False, its not quite as good.
True or false… acetaminophen does not cause GI problems, clotting effects, Reye’s syndrome, and it has little anti-inflammatory effects
True
What is one side effect associated with acetaminophen?
Acetaminophen is a liver toxin at high doses
Patients with compromised livers should not use.
What are some analgesic features of NSAIDs?
Lessens somatic pain (most dental pain, most headaches besides migraines, most muscle and joint pains, most earaches)
Used for mild - moderate pain (has a plateau)
Part of the analgesia relates to their anti-inflammatory action