opioids

Question 1

faster, myelinated, respond to noxious mechanical stimuli, initial pain sensation

Answer 1

A-delta fibers

Question 2

slower, unmyelinated axons, respond to thermal, mechanical and chemical stimuli, dull aching or burning pain

Answer 2

C-fibers

Question 3

t/f: 5x more A-delta fibers than C fibers

Answer 3

FALSE

Question 4

what nociceptor channels can be activated by acid?

Answer 4

TRPV1 and TASK channels

Question 5

where do non-steroidal and steroidal anti-inflammatories serve to diminish pain?

Answer 5

at the periphery

Question 6

where do local anesthetics inhibit pain?

Answer 6

inhibit signaling to CNS

Question 7

where to opioids inhibit pain?

Answer 7

at the periphery and inhibit CNS activity

Question 8

4 families of endogenous opioids

Answer 8

1. pro-opiomelanocortin peptides
2. pro-enkephalin peptides
3. prodynorphin peptides
4. endomorphins

Question 9

3 opioid G-protein coupled receptors that all activate G-alpha-inhibitory

Answer 9

1. mu
2. kappa
3. delta

Question 10

what are the natural agonists of the delta receptor?

Answer 10

met-enkephalin and leu-enkephalin

Question 11

what is the natural agonist of the mu receptor?

Answer 11

Beta-endorphin

Question 12

what are the agonists of the kappa receptor?

Answer 12

dynorphin A, B and alpha/beta neo-endorphin

Question 13

which delta receptor agonist is derived from pro-enkephalin peptides?

Answer 13

met- and leu-enkephalin

Question 14

Beta-endorphin is derived from _________.

Answer 14

pro-opiomelanocortin (POMC)

Question 15

where is beta-endorphin made?

Answer 15

pituitary and hypothalamus

Question 16

opioid receptors activate ________ and _________ which leads to activation of _________ channel which will hyperpolarize the cell.

Answer 16

G-alpha-i, G-betaG-gamma, potassium

Question 17

activation of G-inhibitory will inhibit __________ and decrease_________ which will reduce protein kinase___ which will reduce ________ entry.

Answer 17

adenyl cyclase, cAMP, A, Ca2+

Question 18

what effect will Ca2+ reduction and hyperpolarization by opioids have on the synapse (pre and post)?

Answer 18

pre-synaptic: Ca2+ and hyperpolarization reduce transmitter release

post-synaptic: hyperpolarization will diminish AP generation

Question 19

all 3 opioid receptors can produce which effect?

Answer 19

analgesia

Question 20

the majority of analgesic drugs act primarily at which receptors?

Answer 20

mu

Question 21

mu receptors are mainly __________ (pre/post synaptic) and mainly found in ____________.

Answer 21

presynaptic

PAG, sup dorsal horn, nucleus accumbens, amygdala, cerebral cortex and GI tract inhibits peristalsis

Question 22

how do opioids inhibit ascending pain pathway?

Answer 22

• inhibit excitatory neurotransmitter release at spinal cord

- inhibit transmission of impulse at peripheral sensory nerve

Question 23

how do opioids inhibit descending pain pathway?

Answer 23

opioids inhibit GABA release

• GABA activates Cl- channel which hyperpolarizes
• opioids inhibit the inhibitor to activate pathway that produces CNS mediated pain inhibition

Question 24

t/f: ALL opioid analgesics produce analgesia, respiratory depression, constipation, GI spasm, and physical dependence

Answer 24

true

Question 25

morphine is a prototypic _________ of the mu receptor and produces analgesia w/o _____________ along with a combination of __________ and ________ effects.

Answer 25

full agonist, sedation, stimulatory, depressive

Question 26

the process of _____________ converts morphine into its inactive, toxic form _____________, or its more active analgesic form _______________.

Answer 26

glucuronidation, morphine-3-glucuronide, morphine-6-glucuronide

Question 27

morphine affects the motivational-affective component of the _________ system since patients report that pain is still present but not unpleasant.

Answer 27

limbic

Question 28

____________ is the most serious acute adverse effect of all opioids.

Answer 28

respiratory depression

Question 29

morphine tolerance develops ___________ after starting tx.

Answer 29

5-7 days

Question 30

morphine is metabolized by ______ in the liver. M-3-G is the __________ product and M-6-G is the _________ products.

Answer 30

UGT2B7

Question 31

codeine has a substitution at the ____position which makes it more effective orally than morphine.

Answer 31

3

Question 32

codeine binds poorly to ______ receptor.

Answer 32

mu

Question 33

what is codeine's active form?

Answer 33

codeine-6-glucuronide

Question 34

which form of morphine can cross the BBB?

Answer 34

M-G-6 and morphine

Question 35

codeine is given at a dosage of _______. side effects are _______ at this dose, and don't usually see dependence.

Answer 35

30-60mg/day, minimal

Question 36

t/f: pain with an inflammatory component should not be treated without an anti-inflammatory drug.

Answer 36

true

Question 37

the controlled release form of hydrocodone is _________ and has potential for abuse since there is more drug/ pill.

Answer 37

oxycotin

Question 38

mu receptor antagonists to treat opioid toxicity

Answer 38

naloxone (works rapidly), naltrexone, nalmefene (lasts the longest)

Question 39

mixed agonist-antagonist rationale

Answer 39

formulate drugs that act on kappa or delta receptors that don't have major adverse affect

Question 40

opioids primarily used in dentistry via oral admin

Answer 40

codeine, hydrocodone, oxycodone, pentazocine

Question 41

pentazocine is an antagonist/ partial agonist for the ____ receptor and and agonist for the _____ receptor.

Answer 41

mu, kappa

Question 42

dihydrocodeine, oxycodone (percocet), hydrocodone (vicodin) are all similar to _________, all methylated at ____ position and can all be taken_________.

Answer 42

morphine, 3, orally