Opioids Flashcards
What are opioids used for?
Analgesia
Sedation
Cough Suppression
Treatment of Diarrhea
What are the 3 main analgesia opioid receptors?
MU (MOR)
Delta (DOR)
Kappa (KOR)
What is the mechanism of action for opioids?
Presynaptically: Inhibits the opening of Calcium channels
Post-synaptically: Opens potassium channels
MOR stimulation causes…
Intense analgesic effect
respiratory depression
DOR stimulation causes…
Similar analgesic to MOR
slightly less respiratory depression
KOR stimulation causes…
moderate analgesia effect
little respiratory depression
What is sigma R?
An opioid receptor not involved in analgesia
What does sigma R stimulation cause?
Dysphoria
Respiratory stimulation
Opioids can stimulate opioid receptors either _____ or _____
maximally or weakly
Some opioids may be agonists at some receptors and ____ at other receptors
antagonists
Fentanyl is a ____ while pentazocine is a _____
fentanyl is a full MU agonist while pentazocine is a full Kappa agonist and partial Mu agonist
Due to their different receptor affinity, fentanyl and pentazocine are
receptor competitors (pentazocine can antagonize fentanyl)
Opioids have a high ____ effect
first-pass
What are the physiological effects of full MU agonists like MORPHINE?
CNS: analgesia and sedation
Cardiovascular: not much
Respiratory: dose-dependent depression
GI: Constipation, Nausea
Urinary: Urgency but difficulty pissing
Full MU agonists like morphine and fentanyl are used to treat…
moderate to severe pain
