Flashcards in Exam 4 - opioid analgesics Deck (50):
The descending pain modulating system projects via the _____ to the spinal cord ____ ____. Contains high concentrations of endogenous _____ _____. It is activated by _____ analgesics like certain kinds of ____.
Opiates produce analgesia by ____ ____ on the CNS
Name for pain receptors?
How do systemic administration of opiates produce analgesia?
By acting at widely distributed sites throughout the CNS
The pain suppression system is controlled by what?
Serotonin and also partially enkephalin-mediated
What 4 things is the pain suppression system activated by?
1. Noxious stimuli
3. Psychological factors (including placebos)
What do opioid analgesics take place?
The analgesia system is mediated by what 3 things?
1. periaqueductal grey matter (midbrain)
2. nucleus raphe magnus (medulla)
3. pain inhibitory neurons (dorsal horn)
Proper name for endogenous morphine?
Endorphin - opiate like effect
What 5 places are endorphins found?
3. adrenal medullart chromaffin cells
4. cns (arcuate nucleus hypothalamus, pituitary/nucleus tractus solitarii, visceral afferents from CN VII, IX, X)
5. pancreatic islet cells
T/F endorphins are involved in blood pressure regulation, temperature regulation, and food intake.
What are the 3 precursor molecules of endorphins?
1. proenkephalin A
2. pro-opiomelanocortin (POMC) = B-endorphin
3. Proenkephalin B (prodynorphin) = dynorphins
Endorphins act via what receptor in the GI tract?
What side effect does this cause?
Side effect = constipation
_____ mimics opiate activity = weak analgesics
Where are enkephalins found in the body?
Widely distributed - NT in many brain areas: PAG, RVM, spinal cord laminea
May be responsible for producing analgesia in placebo responders like _____.
What receptors do enkephalins act through?
Mu and delta
What works through the kappa receptors?
What 3 places are dynorphins found?
1. Spinal cord
2. through out brain
Opiate effect depends on what?
Site of binding - highly specific = STEREOSPECIFIC
(Only levo-isomers have biological activity)
What receptor is endorphin activated and gives the best pain relief but highest risk for addiction and possible respiratory depression?
(M2 - respiratory depression)
Which receptor is enkephalins activated and has an effect on analgesia, emotion, and seizures?
Which receptor is dynorphins activated and causes spinal analgesia, miosis, and sedation?
What receptor, although no longer classified as an opioid receptor, causes hallucinations, nightmares, anxiety, and tachycardia?
Besides mu, delta, and kappa, what opioid receptor provides analgesia effects?
Strength of attachment of an opioid drug to its binding site (binding affinity) is proportional to its ______.
What happens with continued exposure of tissues to high concentrations of opioid agonists?
Tolerance - the potency of the drug declines so that progressively higher concentrations are required to produce the same degree of analgesia
Characteristic of all opioids
Cross tolerance develops as well
What are 4 desired clinical effects produced by all opiate drugs?
1. Potent analgesia
2. Sedation and euphoria
3. Cough suppression
4. GI effects (increase smooth muscle tone -> constipation, used as diarrhea tx)
There are 15 common adverse effects produced by all opiate drugs. What are they?
(Severity of side effect is proportional to efficacy)
1. Physical addiction
2. Respiratory depression
6. Urinary retention
7. CNS effects - anxiety, restlessness, nervousness, dysphoria
8. Cardiovascular - postural hypotension, bradycardia
9. Biliary tract constriction - biliary colic
10. Histamine release
11. Pregnancy/lactation - prolong labor, depress fetal respiration, cross breast milk
12. Develop tolerance
13. May cause an adverse reaction
What are some side effects of withdrawal?
yawning, lacrimation, perspiration, rhinorrhea, gooseflesh/piloerection, irritability, nausea, vomiting, tachycardia, tremors, chills
Identify the life-threatening adverse event associated with opiate overdose.
What are the 2 opiate antagonists?
1. naltrexone (Depade, ReVia, Vivitrol) - oral or IM
2. naloxone (Narcan) - IV to reverse OD
Where is opium from?
Dried juice obtained from unripe seed capsules of poppy plant
What are 2 common derivatives of opium used in dentistry?
Arrange these common opioids according to potency, highest to lowest.
meperidine, codeine, dihydrocodeine, fentanyl, morohine, hydrocodone.
1. fentanyl = 100x more potent than morphine and 500x more than meperidine
2. morphine = oxycodone
4. hydrocodone = 3x more than codeine
6. dihydrocodeine = codeine (same efficacy/potency)
What is the optimum dose of codeine?
60 mg - no increased effect after this, but increased adverse events
What is the most widely prescribed codeine product in dentistry?
Tylenol 3 (3 =30 mg codeine)
Codeine is used for moderate to moderately severe pain and what else?
hydrocodone is 3x more potent than codeine, what are 2 examples with acetaminophen?
1. Viodin (5/500 or 7.5/500)
2. Lorcet/Lortab (5/500 or 7.5/500)
What drug uses a lower dose of acetaminophen but is still a strong opiate dose?
10 mg hydrocodone with 325 mg acetaminophen
Does hydrocodone with ibuprofen have enough enough ibuprofen for an anti-inflammatory response?
No use OTC to supplement
Which opioid is highly addictive, as potent as morphine, more potent than codeine, has more side effects, and used to treat severe pain? Know the 4 brand names
oxycodone - schedule 2
What is the most widely used hydrocodone preparation used by dentists?
hydrocodone with acetaminophen
Vicodin or Lorcet
In dentistry, when would you use meperidine (Demerol)?
IV conscious sedation or orally for moderate to severe pain. Not as potent as fentanyl so less risk of respiratory depression but may cause nausea
In dentistry, when would you use fentanyl?
Conscious sedation only! Given through IV, transdermal, and lollipop
What drug is used for short term acute dental pain (less than 5 days), it inhibits the reuptake of norepinephrine and serotonin, and associated with seizures?
What drug is used for short term acute dental pain (less than 5 days), is not an opioid but gives relief at that level. Watch for bleeding and GI complications.
ketorolac (Toradol) - NSAID
Why are NSAIDs preferred to an opiate for pain management?
Opiates do not reduce inflammation and treating inflammation will decrease pain
All opiates have adverse side effects - especially nausea and constipaiton
When would you prescribe someone meperidine (demerol)?
For patients with a history of codeine allergy