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Pharmacology 2100 > Opiods > Flashcards

Flashcards in Opiods Deck (50):
1

what are the endogenous opioids

endorphins
enkephalins
dynorphins

2

how do opioids work

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

3

pharmacological effect of opioids*

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

4

what is the main cause of death from opioid overdose

depression of respiration
clinically useful at end of life COPD

5

what can opioids be used for

pain
diarrhea
coughing
panic breathign - COPD

6

how do you give opioids

by the mouth
by the clock
by the ladder

7

what is the WHO pain ladder

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

8

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

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

9

why do you dose by the clock

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

10

why do you dose by the ladder

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

11

codeine

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

12

tramadol mechanism of action

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

13

oral morphine

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

14

IV morphine

twice as potent
can be immediate onset or take 2 hours

15

oxycodone

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

16

forms of oxycodone

slow release - oxycotin
with tylenol - percocet, high overdose risk

17

hydromorphine

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

18

fentanyl

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

19

sufentanyl

more potent than fentanyl

20

naltrexone

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

21

what can naltrexone be used to treat

alcohol addiction

22

naloxone

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

23

methadone

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

24

why does methadone have high risk of overdose

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

25

how do you switch from one opioid to another

find the equivalent dose and then use 70% of it

26

when should you discontinue therapy

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

27

what is tolerance

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

28

symptoms of opioid withdrawl

yawning
sweating
tremor
fever
increase HR
insomnia
cramps
dilated pupils

29

how do you avoid dependence

decrease dose by 20-30% a day

30

what is addiction

psychological dependence

31

how does NE and serotonin mediate pain

inhibit pain signals from reaching higher levels of the brain

32

how are tricyclic antidepressants used to treat pain

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

33

selective serotonin reuptake inhibitors side effects and examples

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

34

serotonis and NE reuptake inhibitors side effects and example

suicidality
serotonin syndrome
venlafaxine

35

alpha adrenergic agonists

clonidine and tizantidine
many side effects

36

what drugs act on descending pathways

all antidepressants
alpha adrenergic agonist

37

what is peripheral sensitization

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

38

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

carbamazepine
tricycle antidepressants
topiramate
lidocaine

39

carbamazepine

anticonvulsant
limits influx of sodium ions across the cell membrane

40

topiramate

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

41

lidocaine

sodium channel blocker

42

what are descending inhibitory pathways

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

43

what is central sensitization

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

44

what are meds that prevents central sensitization and how

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

45

what is another way to preven tcentral sensitization

NMDA antagonists for receptors in the spinal cord
ketamin
dextromethorphan
methadone

46

ketamine

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

47

what are the excitatory NT

glutamate and substance P

48

dextromethorphan

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

49

methadone

opioid agonist, blocks NMDA receptors, inhibits NE reuptake

50

what are advantages of methadone

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