opioids Flashcards
endogenous opioid peptides
enkephalins endorphins dynorphins
endogenous ligands for mu receptor
enkephalins, B-endorphin
drug ligands for mu receptor
morphine, fentanyl, methadone, meperidine, buprenorphine
endogenous ligands for kappa receptor
dynorphins
drug ligands for kappa receptor
butorphanol, pentazocine, nalbuphine
endogenous ligands for delta receptor
enkephalins, B-endorphin
drug ligands for delta receptor
none
opioid pharmacology
analgesia, cough suppression, antidiarrheal effect/constipation, euphoria, sedation, respiratory depression, nausea, endocrine effects, pupillary constriction
mu agonist, low oral to parenteral potency ratio (3/4:1); IV/oral/sustained oral/suppository available, 4-5 hr analgesia
morphine
mild to moderate pain, some metabolized to morphine, often used with NSAID/acetaminophen
codeine
more efficacious than codeine, used alone for moderate to severe pain, available as sustained release oral
oxycodone
moderate to moderate/severe pain, usually combined with NSAID/acetaminophen, sustained release available
hydrocodone
diacetyl morphine, more lipophilic than morphine, converted to 6-mono-acetyl morphine and morphine
heroin
phenylheptylamine, mu agonist, equipotent with morphine, good oral availability, longer duration of action, used in treatment of opioid abuse and pain, long half life (a day)
methadone
phenylpiperidine, shorter duration of analgesia, forms toxic metabolite that can accumulate, interactions with MAO inhibitors
meperidine