Opiods

Question 1

what are the endogenous opioids

Answer 1

endorphins
enkephalins
dynorphins

Question 2

how do opioids work

Answer 2

1. hyperpolarization of nerves by openign potassium and calcium channels in neurons
2. inhibition of ascending pathways in CNS
3. excitation of descending adrenergic and seratonerigic pathways

Question 3

pharmacological effect of opioids*

Answer 3

inhibition of pain and pain perceptions 
sedation adn anxiolysis 
depression of respiration 
cough suppression 
reduction of intestinal motility
pupillary constriction 
nasuea and vomiting at first

Question 4

what is the main cause of death from opioid overdose

Answer 4

depression of respiration

clinically useful at end of life COPD

Question 5

what can opioids be used for

Answer 5

pain
diarrhea
coughing
panic breathign - COPD

Question 6

how do you give opioids

Answer 6

by the mouth
by the clock
by the ladder

Question 7

what is the WHO pain ladder

Answer 7

mild pain 0-3: acetaminophen and NSAIDS
moderate pain 4-6: mild opioid codiene
severe pain 7-10: strong opioid morphine
must keep all of the pain controls all the way up the ladder bc work in different ways

Question 8

oral dosing has first pass metabolism so is less effective than IV so why is it still recommended

Answer 8

longer term effect requiring less frequent doses
avoids highs and thus is less addictive
oral dosing safer

Question 9

why do you dose by the clock

Answer 9

takes less drug to maintain a person drug free than to bring pain down again
avoids euphoria associated with release of pain so less addictive
avoids development of chronic pain syndromes from pain pathway rewiring

Question 10

why do you dose by the ladder

Answer 10

assures safest and least potent drug required for any case is used
avoids addictive potential bc strong opioids not used until required

Question 11

codeine

Answer 11

weakest commonly used opioid with little addiction risk
very low potency
pain, diarrhea, coughing, inhibit breathing

Question 12

tramadol mechanism of action

Answer 12

activates gamma opioid receptor
weak inhibitor of NE and serotonin
less potential for addiciton, greater pain control

Question 13

oral morphine

Answer 13

poor availability due to first pass metabolism
onset cna take an hour
lasts 3 hours

Question 14

IV morphine

Answer 14

twice as potent

can be immediate onset or take 2 hours

Question 15

oxycodone

Answer 15

similar potency to morphine but oral bioavailability
longer half life
dosed at half morphine dose

Question 16

forms of oxycodone

Answer 16

slow release - oxycotin

with tylenol - percocet, high overdose risk

Question 17

hydromorphine

Answer 17

oral onset half an hour 
IV lasts 3 hours 
peak effect in an hours 
more potent than morphine
used in surgical settings

Question 18

fentanyl

Answer 18

very lipophilic and potent
sublingual for acute temporary pain 1-2 hrs
transdermal used for long term severe 72 hrs

Question 19

sufentanyl

Answer 19

more potent than fentanyl

Question 20

naltrexone

Answer 20

oral opioid inhibitor
reverses psychotomimetic effects of opiate agonists, reverses hypotension and cardiovascular instability
completely shuts off opioid receptor

Question 21

what can naltrexone be used to treat

Answer 21

alcohol addiction

Question 22

naloxone

Answer 22

potent opioid antagonist
blocks opioid binding
dont work orally so put in opioids to prevent OD from injection
used for emergency respiratory depression
short half life

Question 23

methadone

Answer 23

requires special training
less addictive
more potent than morphine
used where patient developed resistance or toxicity to others

Question 24

why does methadone have high risk of overdose

Answer 24

half life of 5 days but only effective for 6-12 hours

accumulates

Question 25

how do you switch from one opioid to another

Answer 25

find the equivalent dose and then use 70% of it

Question 26

when should you discontinue therapy

Answer 26

intolerable side effects high doses of opioids with no analgesia evidence of addiction patient to comfortable makes no effort to increase function may require cognitive bahavoural program

Question 27

what is tolerance

Answer 27

reduced potency of analgesic effects of opioids following repeated admin related to opioid receptor regulation

Question 28

symptoms of opioid withdrawl

Answer 28

``` yawning sweating tremor fever increase HR insomnia cramps dilated pupils ```

Question 29

how do you avoid dependence

Answer 29

decrease dose by 20-30% a day

Question 30

what is addiction

Answer 30

psychological dependence

Question 31

how does NE and serotonin mediate pain

Answer 31

inhibit pain signals from reaching higher levels of the brain

Question 32

how are tricyclic antidepressants used to treat pain

Answer 32

increase serotonin and NE in synapse take 1-3 weeks so used for chronic also good to treat comorbidities of depression

Question 33

selective serotonin reuptake inhibitors side effects and examples

Answer 33

inhibits s reuptake suicide, sexual dysfunction, impaired platelet aggregation paroxetine, fluxoxetine, sertraline

Question 34

serotonis and NE reuptake inhibitors side effects and example

Answer 34

suicidality serotonin syndrome venlafaxine

Question 35

alpha adrenergic agonists

Answer 35

clonidine and tizantidine | many side effects

Question 36

what drugs act on descending pathways

Answer 36

all antidepressants | alpha adrenergic agonist

Question 37

what is peripheral sensitization

Answer 37

spontaneous peripheral nerve activity mediated by sodium channel, drugs work here by blocking sodium channels

Question 38

what are classes of drugs that dampen the sodium channels on nerves

Answer 38

carbamazepine tricycle antidepressants topiramate lidocaine

Question 39

carbamazepine

Answer 39

anticonvulsant | limits influx of sodium ions across the cell membrane

Question 40

topiramate

Answer 40

anticonvulsant | limits sodium ions across the cell membrane and antagonizes glutamate receptors

Question 41

lidocaine

Answer 41

sodium channel blocker

Question 42

what are descending inhibitory pathways

Answer 42

NE, serotonin, and endorphines inhibit pain signlas from reaching higher levels of brain , drugs work here by inhibiting reuptake or stimulating the adrenergic system

Question 43

what is central sensitization

Answer 43

release of excitatory NTs in the dorsal horn of the spinal cord, increased calcium transport causes spontaneous impulses and a pain message to the brain

Question 44

what are meds that prevents central sensitization and how

Answer 44

decrease calcium channel activity by binding to alpha2-delta subunit of presynaptic neurons gabapentin and pregablin

Question 45

what is another way to preven tcentral sensitization

Answer 45

NMDA antagonists for receptors in the spinal cord ketamin dextromethorphan methadone

Question 46

ketamine

Answer 46

NMDA receptor antagonist decreases central sensitization and modulation by lowering threshold for nerve transduction reduces effects of substnace p

Question 47

what are the excitatory NT

Answer 47

glutamate and substance P

Question 48

dextromethorphan

Answer 48

low affinity uncompetitive NMDA antagonists binds opioid receptors could cause serotonin syndrome

Question 49

methadone

Answer 49

opioid agonist, blocks NMDA receptors, inhibits NE reuptake

Question 50

what are advantages of methadone

Answer 50

less need for opioid escalation not active metabolites highly lipophilic, high bioavailability