OPIOIDS

Question 1

why is an opioid used an an analgesia?

Answer 1

it inhibits pain signal generation during and after surgical procedure.
it can cause profound sedation, and can be used as an antitussive.

Question 2

define opiate

Answer 2

natural component of opium

Question 3

define opioid

Answer 3

opiates & synthetic drugs related to morphine

Question 4

name 4 uses for opioid drugs.

Answer 4

1. analgesia (moderate/sever pain)
2. sedation
3. cough surpression
4. treatment of diarrhea

Question 5

what are the pre and post synaptic opioid mechanisms?

Answer 5

pre: inhibits opening of Ca2+ channels which inhibits NT release
post: opens K+ channels, which inhibits depolarization.
inhibits the NT released in pain pathways, in resp. center, cough center, ANS pathways.

Question 6

na,e the 4 opioid receptor types and where are they locateD?

Answer 6

Mu (μ: MOR)
delta ( δ: DOR)
kappa (κ: KOR)
sigma σ
brain, spinal cord, peripheral pain fibres.

Question 7

what are the adverse effects of opioids?

Answer 7

constipation, nausea, urinary retention, resp. Depression, dysphoria.

Question 8

what are the resulting effects from MOR stimulation?

Answer 8

Analgesia
Euphoria
miosis
respiration depression.

Question 9

what are the resulting effects from DOR stimulation?

Answer 9

**Analgesia

some euphoria, miosis and Resp. depression.

Question 10

what is the resulting effect from KOR stimulation?

Answer 10

weak Analgesia.

Question 11

what are the resulting effects from sigma R stimulation?

Answer 11

Dysphoria
hallucinations
resp. & vasomotor stimulation

Is a highly atypical opioid receptor

Question 12

what are some unique properties of opioids in relation to agonist, and antagonist characteristics?

Answer 12

max stim. = full agonist
weak stim. = partial agonist

some opioids are agonists at some opioid receptors, and antagonist at others.

Question 13

what is the pharmacoinetics of most opioids?

Answer 13

high first-pass effect, therefore most opiods are administered parenterally.

Question 14

what is the metabolism effect on opioids?

Answer 14

hepatic P450 enzyme system, where 10% of codeine is metabolized into morphine -> main source of codine effect.

Question 15

what are the physiological effects of opioids in the CNS

Answer 15

4-6 hours of analgesia and sedation (not sleep)

Question 16

what are the physiological cardiovascular effects of opioids?

Answer 16

little, but morphine may cause histamine release —> hypotension

Question 17

what are the physiological effects on the respiratory system from opioids?

Answer 17

dose-dependent depression
intense effect when combined with general anesthetic
death from resp. arrest
cough surpressant

Question 18

what is used as a treatment of opioid over-dose? ie. opioid antagonist?

Answer 18

naloxone, it binds and blocks most receptors as a competitive inhibitor.
used also to treat circulatory shock, as well as reverse profound sedation.

Question 19

what are the physiological effects on the gastrointestinal tract from opioids?

Answer 19

constipation
bile duct sphincter construction—-> biliary colic
nausea and vomiting

Question 20

what are the physiological effects of opioids on the urinary system?

Answer 20

bladder sphincter tone increases, destrussor muscle tone increased. Need topee but cant.

Question 21

fentanyl (type of drug, use, overdose, administration)

Answer 21

full mu antagonist
profound pain relief
overdose: seizures/ conspitating
administered: topical patch

Question 22

etorphine (use, recovery, speciality uses)

Answer 22

wildlife-sedation
reversal agent required to recover
used under license with 2 people present

Question 23

name two anti-diarrhea drugs and how do they work

Answer 23

loperamide and diphenoxylate

reduce propulsive gut motility and gut secretions, also constructs anal sphincter.

Question 24

what is meperidine, and its downfall.

Answer 24

1/10th analgesic potency of morphine, can depress heart. releases toxic metabolites called normeperidines.

Question 25

describe normeperidines.

Answer 25

accumulates over long term esp. when renal function is impaired, causes CNS stimulation, and may lead to dysphoria, agitation and seizures.