5a: Opioids Flashcards
uses for opioid analgesics
- moderate to severe pain, such as trauma, surgery, chronic pain, advanced cancer
- considered a controlled substance in US
mechanism of opioid analgesics
bind to specific neuron receptors located in the CNS, used by both exogenous and endogenous opioids
examples of endogenous opioids
endorphins, enkephalins, dynorphins (produced by the body)
three primary classes opioid receptors
Mu, Kappa, Delta (stimulation of any of these causes analgesia)
side effects of Mu receptor stimulation
respiratory depression, constipation, opioid abuse, addiction
mixed agonist-antagonist opioids
opioids that stimulate kappa receptors while avoiding or blocking mu receptors; these are less likely to cause respiratory depression or abuse
strong agonists
used for treating severe pain, primarily Mu receptors (ex: morphine, fentanyl)
mild-to-moderate agonists
used for moderate pain, do not have as high of an affinity as strong agonists (ex: codeine, oxycodone)
antagonists
used to treat opioid overdoses and addiction; block all opioid receptors (increased affinity for Mu), will not produce analgesia (ex: naloxone)
pharmacokinetics of opioids
- admin: many ways
- main effects after they reach CNS, metabolized mostly in liver
- excreted in urine
sites of opioid effects
spinal, brain (supraspinal), peripheral
other uses of opioids
cough suppressors, control severe diarrhea, adjunct to general anesthesia
adverse effects of opioids
sedation, drowsiness, euphoria, respiratory depression, GI distress (N, V, constipation), addiction, tolerance
opioid withdrawal timeline
evident 6-10 hours after the last dose and will continue for 5 days
opioid withdrawal symptoms
body aches, diarrhea, fever, tachycardia, weakness/fatigue, shivering, sweating, irritability, N&V