Opioids Flashcards
the opioid receptor subtypes and their functions
mu- supraspinal analgesia, miosis, respiratory depression, dependence
delta- less dependence
kappa- weak miosis, sedation, weak resp depression, dysphoria
what type of receptors are the opioid receptors?
GPCR and 7x transmembrane proteins
the endogenous opioids and what receptors they have highest affinity for
endorphins- mu
enkephalins- delta
dynorphins- kappa
at what levels do opioids inhibit pain neurotransmission?
spinal and supraspinal levels
mechanism of action of mu opioid receptor agonists
presynaptic: decrease Ca2+ influx
postsynaptic: increases K+ conduction, decreases postsynaptic response
therapeutic effects of opioids
analgesia for dull pain, produces constipation, antitussive
adverse effects of opioids
respiratory depression, miosis, sedation and euphoria, emesis, cardiovascular, urinary retention, biliary spasm, muscular rigidity of chest wall
the opioid that has anticholinergic effects, i.e. does not give pinpoint pupils (miosis)
meperidine (Demerol)
difference between tolerance and dependence
tolerance- higher dose required
dependence- causes withdrawals; may be physical (not life-threatening) or behavioral
prototype mu agonist
morphine
the phenanthrenes (mu agonists)
morphine, heroin, codeine
the phenyl-piperidines (mu agonists)
meperidine, fentanyl and congeners
what opioid drug comes in a nasal spray?
fentanyl
methadone derivatives (mu agonists)
methadone, propoxyphene
mixed mu agonists-antagonists and partial mu agonists
pentazocine, buprenorphine, tramadol
