Opioid Antagonists

Question 1

All opioid antagonists are

Answer 1

mu receptor antagonists and competitive antagonists

Question 2

naloxone is a _____ selective antagonist

Answer 2

non selective; acts on all three opioid receptors

Question 3

most significantly, naloxone can

Answer 3

reverse opioid RD in neonates and antagonize volatile anesthetics at high doses

Question 4

naloxone is safe in ____ and ____ shock because it will increase myocardial contractility

Answer 4

septic and hypovolemic

Question 5

dont give naloxone quick - give over

Answer 5

2-3 minutes

Question 6

naloxone duration

Answer 6

30-45 mins - so may need redosing

Question 7

significant s/e of naloxone

Answer 7

NV, reversal of analgesia, increased SNS response causing potentially fatal v fib and pulm edema

Question 8

naltrexone is more effective

Answer 8

PO

Question 9

naltrexone is helpful in

Answer 9

alcoholism

Question 10

naltrexone has a duration of

Answer 10

24 hours

Question 11

nalmefene is equipotent to

Answer 11

naloxone

Question 12

naloxone is more 5 times more effective

Answer 12

IV than PO

Question 13

nalmefene 1/2 time

Answer 13

10.8 hours

Question 14

list the unique traits of methylnatrexone

Answer 14

highly ionized and works more peripherally; promotes gastric emptying and antagonizes N/V; does not alter central analgesia

Question 15

list the unique traits of alvimopan

Answer 15

post op ileus; mu selective PO –> acts peripherally; metabolized in gut flora and can cause cv symptoms with long term use

Question 16

opioid receptors are present on immune cells therefor chronic use of opioids can cause

Answer 16

immunosuppression

Question 17

abuse resistant opioids are formulated how

Answer 17

more difficult to ingest active ingredient by mixing opioid with antagonist

Question 18

do opioid allergies really exist

Answer 18

usually just s/e of the medication; only 3 reported cases of true fentanyl allergy

Question 19

3 mcg/kg fent 25-30 mins pre op will decrease MAC of des and iso by

Answer 19

50%

Question 20

sufentanil decreases MAC with enflurane by

Answer 20

70-90%

Question 21

alfentanil decreases MAC up to

Answer 21

70%

Question 22

remi decreases AMC by

Answer 22

50-90%

Question 23

when giving neuraxial opioids we target

Answer 23

opioid receptors in lamina II or the substantia gelatinosa

Question 24

a neuraxial opioid is injected into the

Answer 24

epidural or sas

Question 25

targeting neuraxial opioids will NOT cause

Answer 25

sympathectomy, sensory block, or weakness

Question 26

epidural dosing is 5-10x more than

Answer 26

sas/intrathecal dose

Question 27

when we give an epidural, the opioid

Answer 27

stays in the sas and must diffuse across the dura mater for systemic absorption

Question 28

highly lipophilic fentanyl and sufentanil diffuse better in an epidural but morphine

Answer 28

has a longer duration

Question 29

where do we want the epidural opioids to work/go

Answer 29

csf

Question 30

places of epidural opioid uptake

Answer 30

epidural fat, epidural venous plexus, and diffusion across the dura

Question 31

if the epidural opioid goes to the epidural venous plexus there will be systemic absorption; how can we counteract this?

Answer 31

epi

Question 32

epidural fent peak

Answer 32

20 mins

Question 33

epidural sufentanil peak

Answer 33

6 mins

Question 34

if a drug is more cephalad it means that it is

Answer 34

more likely to travel up the spinal cord; more h2o soluble

Question 35

fent and sufent are lipid soluble. _____ is less lipid soluble and more likely to hang out in the cns and go ______

Answer 35

cephalad

Question 36

body position has little effect on whether or not a drug goes cephalad; these have more effect

Answer 36

coughing, blowing, straining

Question 37

most common s/e of neuraxial opioids

Answer 37

pruritis, n/v, urinary retention, RD, sedation, CNS excitation, herpes simplex labialis, neonatal morbidity