Opioids Analgesics and Antagonists Flashcards Preview

BCN EXAM 4 > Opioids Analgesics and Antagonists > Flashcards

Flashcards in Opioids Analgesics and Antagonists Deck (71):
1

Oxymorphone

very similar to morphine but 10 times more potent. it is also more expensive
Post surgical pain relief lasts two to six hours although some clinicians claim it has a slightly shorter duration of action than morphine
lesser tendency to induce vomiting
does not cause histamine release
less depressant effect on the respiratory center

2

What should be administered with Oxymorphone

an Anti Ach to avoid/prevent severe bradycardia

3

Meperidine mechainsm of action

mu opioid receptor in CNS and PNS of the bowels

4

meperidine clinical effects

analgesia - about 1/3 the potency of morphine
post-anesthetic shivering
adverse effects and side effects equivalent to morphine
CNS excitation - normeperidine

5

Meperidine absorption

50% excapes first pass effect after oral admin
BBB - crosses more readily than morphine

6

Meperidine congeners - Dipheoxylate

constipation - treatment of diarrhea
high doses - typical opioid effects

7

Meperidine congeners - Loperamide

Antidiarrheal - slows gastric motility, decreases GI secretion, poor BBB penetration

8

Fentanyl

75 to 200 times more potent than morphine
short duration of action (45-60 minutes)***
minimal CV effects except for bradyarrhythmias
respiratory center depression can be more severe than with morphine and apnea may occur

9

Alfentanyl

new synthetic compound with ultrashort half life

10

Sufentanyl

half life shorter than fentanyl but with fewer side effects

11

Fentanyl congeners - Sufentanil

profile like fentanyl, but 500 to 1000 times more potent than morphine

12

Fentanyl congeners - Alfentanil

~20-30 less than fentanyl
broken down by plasma esterases - 1/2 life is about 8-20 min

13

Fentanyl congeners - Remifentanil

equipotent with fentanyl
metabolized by the liver - 1/2 life is about 1 to 2 hrs

14

piperidines: therapeutics

alfentanil and remifentanil
short, painful procedures
-intense analgesia and suppressing stress response

15

Absorption of opiates

most opiates are rapidly absorbed in the GI tract
undergo a high rate of first pass metabolism
highly lipophilic opiates can be absorbed transdermally

16

distribution of opiates

all opiates bind to plasma proteins at varying affinities
will rapidly leave the blood to concentrate in other body tissues

17

metabolism of opiates

first pass effect
most opiates are converted to more polar metabolites via hepatic conjugation to glucuronides or N-demethylated
6-glucuronide is more potent and the 3-glucuronide is inactive and is the highest concentration metabolite found in the urine.
certain opiates like fentanyl are metabolized by cyto P450

18

excretion of opiates

occurs primarily through the kidneys

19

morphine metabolism

conjugation with glucuronide acid
morphine-6-glucuronide is the active metabolite which is 2x as potent as morphine
First pass effect is significant
about 2 hr half life
most is metabolized and excreted by kidneys

20

Acute morphine poisoning

triad: coma, miosis, cyanosis (affect respiration)
asphyxia, pupils dilate, biliary spasms, GI smooth muscle spasm, pulmonary edema, muscle twitches, peripheral vasodilation, hypotension results in shock
Respiratory failure results in death in 2-4 hours

21

Oralet

intrabuccal fentanyl
administered to kids and adults that are about to undergo a surgical procedure (raspberry flavored :9 )

22

Actiq

used or cancer patients for breakthrough pain (higher dose/ no raspberry flavor)
intrabuccal fentanyl

23

intrabuccal fentanyl

takes effect within 15-20 minutes and lasts ~1-2 hrs

24

For chronic malignant pain, use this patch

fentanyl
duration of action of 72 hours

25

LA morphine

provides sustained serum leves of active morphine
Q8-12 hrs (MS contin)
Q12-24 hrs (Kadian)
Q24 hr(avinza)

26

LA oxycodone (oxycontin)

Q8-12 hrs

27

Methadone

Q6-12 hrs
also has NMDA effect specific for neuropathic pain

28

Transdermal fentanyl patch

Q 48-72hrs

29

Oxycodone CR (oxycontin)

pure oxycodone inside a polymer/acrylic matrix that allows for controlled release
Abusers crush the tablet to destroy the matrix and disable the controlled release

30

what is oxycodone metabolized to

oxymorphone, then noroxymorphone and noroxycodone

31

Codeine

Used for moderate pain and as an antitussive***
at high doses causes CNS stimulation
max. analgesia = 12-15%that of morphine

32

what is codeine converted to?

about 10% of codeine (methylmorphine) to morphine

33

improvements in codeine over morphine

less respiratory depression, less dependence and less euphoria than morphine
higher oral efficiency and slower development of tolerance than morphine

34

Tramadol

codeine analog
weak mu agonist
racemic mixture - enantiomers have different acions
mild to moderate pain
68% bioavailability oral vs. parenteral
N&V, dizziness, sedation and headache
seizures

35

tramadol mechanism of action

Norepi reuptake blocker
5HT reuptake blocker

36

Tramadol metabolism

liver - O methylation, metabolite more potent
half life is six hrs

37

tramadol elimination

Renal

38

Hydrocodone

synthetic drug similar in structure to codeine
more potent than codeine comparable to morphine
available in combination with other drugs such as NSAIDs and acetaminophen
single highest prescribed drug in USA
highly abused

39

Pentazocine (Talwin)

1/3 as potent as morphine as analgesic
k agonist, and delta partial agonist
effective orally, shorter duration and faster onset of action than morphine

40

Buprenophine

potent, long acting phenanthrene derivation
m partial agonist
mu and delta antagonist

41

Naloxone hydrochloride

reverse the effects of opioids (including analgesia)
no agonist properties
does not produce respiratory or CV depression. it can be used to reverse the effects (respiratory depression) of any of the opioid agoinst/antagonist group

42

Nalmefene

opioid antagonists

43

Naloxone

antagonizes most opioid receptor agonists
high doses antagonize barbiturates
almost a pure antagonist
used to reverse coma and respiratory depression in opioid overdose (within 30 sec) but short duration of action

44

Naltrexone (Trexan-Dupont)

pure antagonist
orally effective
longer duration of action than naloxone

45

Methylnaltrexone (Relistor)

opioid induced constipation in pts with advanced illness having a inadequate response to traditional laxatives

46

Methylnaltrexone (Relistor) contraindications

mechanical bowel obstruction
stop drug if opioids are discontinued
may cause dizziness
concomitant use with SSRIs, Li, carbamazepine, or valproic acid may produce additive effects

47

Methylnaltrexone (Relistor) contraindicated in patients with ...

severe renal failure (

48

morphine and naltrexone

extended release opioid with sequestered core of the antagonist, naltrexone, in single dosage form
when taken as directed, naltrexone remains sequestered
if capsule is tampered with by crushing, chewing or dissolving then naltrexone negates effects of the opioid

49

What has been found to help enhance the effects of opioids?

addition of low doses of opioid antagonists, like naltrexone or naloxone, in combination with opiates, do not inhibit the analgesia effect but enhance it
reduce withdrawal syndrome, reversed tolerance and restored potency of opiates

50

Buprenorphine pharma

ceiling effect on respiratory depression
less physical dependence capacity
blocks withdrawal in mildy dep ppl
BUT precipitates withdrawal in mod to severe dep ppl

51

Buprenorphine (suboxone, subutex)

20-50 times potency of morphine
schedule III drug
sublingual
Suboxone - bup an Naloxone (4:1)

52

Sufentanil

works on all three opioid receptors

53

Nalbuphine

only kappa receptor

54

Contraindications for mu opioid receptors agonists

impaired pulmonary function
asthma
hepatic or renal disease
hypotension
Phenothiazines (enhanced respiratory depression, sedation)
Antidepressants (enhanced analgesia)
MAO inhibitors (contraindicated with meperidine)

55

side effects/ toxicity of mu opioid receptor agonists

respiratory depression
constipation
N and V
sedation
euphoria
peripheral vasodilation
urinary retention
spasm- sphincter of oddi
prutitus
physical dependance
tolerance
miosis

56

signs and symptoms of opium overdose

sedation
confusion
miosis
respiratory rate
hypoxia
cyanosis

57

Treatment of opium overdose

immediate - resuscitation by maintaining airway, oxygen and naloxone and reversal with IV naloxone or another opioid antagonist

58

Naltrexone

reduces pleasure from opiates
doesnt seem to reduce cravings
best for motivated pts or pregnant pts

59

adverse effects of chronic opiate use

hypogonadism
immunosuppression
increased feeding
increased growth hormone secretion
withdrawal effects
tolerance, dependence
abuse, addiction
hyperalgesia
impairment while driving

60

Opioid withdrawal symptoms stage 1 up to 8 hours

anxiety and drug craving

61

opioid withdrawal symptoms stage 2 8-24 hours

anxiety, insomnia, GI disturbance, rhinorrhea, mydriasis, diaphoresis

62

opioids withdrawal symptoms up to 3 days

tachycardia, N&V, hypertension, diarrhea, fever, chills, tremors, seizure, muscle spasms

63

Treatments for opiate dependence

methadone
buprenorphine
naltrexone

64

Methadone

main action: full opioid agoinst on mu receptor
inhibit adenyl cyclase = decreases cAMP
increases K channel opening
decreases Ca channel opening
inhibits serotonin reuptake
non competitive antagonist of NMDA receptor

65

Steps when detoxing

wait until opiate withdrawal starts when give first dose (30-60min until effect)
maintanence with 16-24 mg qd
max: 32 mg qd

66

opioids and MAOIs

absolute contraindications to meperidine and relative contraindication to other opioids because of high incidence of hyperpyrexic coma

67

opioids and sedative-hypnotics

increased CNS depression, particularly respiratory depression

68

opioids and tricyclic anti-depressants

increased sedation
variable effects on respiratory depression

69

opioids and antipsychotic drugs

increased sedation
variable effects on respiratory depression

70

___________ is used in opiate detox because it has a less severe and shorter duration of withdrawal symptoms compared to ___________

Buprenorphine
methadone

71

symptoms last longest with __________ but are less severe than those of __________ withdrawal

methadone
heroin