OPIOIDS Flashcards
why is an opioid used an an analgesia?
it inhibits pain signal generation during and after surgical procedure.
it can cause profound sedation, and can be used as an antitussive.
define opiate
natural component of opium
define opioid
opiates & synthetic drugs related to morphine
name 4 uses for opioid drugs.
- analgesia (moderate/sever pain)
- sedation
- cough surpression
- treatment of diarrhea
what are the pre and post synaptic opioid mechanisms?
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.
na,e the 4 opioid receptor types and where are they locateD?
Mu (μ: MOR) delta ( δ: DOR) kappa (κ: KOR) sigma σ brain, spinal cord, peripheral pain fibres.
what are the adverse effects of opioids?
constipation, nausea, urinary retention, resp. Depression, dysphoria.
what are the resulting effects from MOR stimulation?
Analgesia
Euphoria
miosis
respiration depression.
what are the resulting effects from DOR stimulation?
**Analgesia
some euphoria, miosis and Resp. depression.
what is the resulting effect from KOR stimulation?
weak Analgesia.
what are the resulting effects from sigma R stimulation?
Dysphoria
hallucinations
resp. & vasomotor stimulation
Is a highly atypical opioid receptor
what are some unique properties of opioids in relation to agonist, and antagonist characteristics?
max stim. = full agonist
weak stim. = partial agonist
some opioids are agonists at some opioid receptors, and antagonist at others.
what is the pharmacoinetics of most opioids?
high first-pass effect, therefore most opiods are administered parenterally.
what is the metabolism effect on opioids?
hepatic P450 enzyme system, where 10% of codeine is metabolized into morphine -> main source of codine effect.
what are the physiological effects of opioids in the CNS
4-6 hours of analgesia and sedation (not sleep)
what are the physiological cardiovascular effects of opioids?
little, but morphine may cause histamine release —> hypotension
what are the physiological effects on the respiratory system from opioids?
dose-dependent depression
intense effect when combined with general anesthetic
death from resp. arrest
cough surpressant
what is used as a treatment of opioid over-dose? ie. opioid antagonist?
naloxone, it binds and blocks most receptors as a competitive inhibitor.
used also to treat circulatory shock, as well as reverse profound sedation.
what are the physiological effects on the gastrointestinal tract from opioids?
constipation
bile duct sphincter construction—-> biliary colic
nausea and vomiting
what are the physiological effects of opioids on the urinary system?
bladder sphincter tone increases, destrussor muscle tone increased. Need topee but cant.
fentanyl (type of drug, use, overdose, administration)
full mu antagonist
profound pain relief
overdose: seizures/ conspitating
administered: topical patch
etorphine (use, recovery, speciality uses)
wildlife-sedation
reversal agent required to recover
used under license with 2 people present
name two anti-diarrhea drugs and how do they work
loperamide and diphenoxylate
reduce propulsive gut motility and gut secretions, also constructs anal sphincter.
what is meperidine, and its downfall.
1/10th analgesic potency of morphine, can depress heart. releases toxic metabolites called normeperidines.
describe normeperidines.
accumulates over long term esp. when renal function is impaired, causes CNS stimulation, and may lead to dysphoria, agitation and seizures.
