Opioids Flashcards
what type of opioid receptor is in the gut?
mew
mew receptors are located where in the neuron
both presynaptically and post-synaptically
kappa receptors are located where in the neuron
presynaptic only
delta receptors are located where in the neuron
presynaptic only
2 pre-synaptic mechanisms that suppress NT release are:
- inhibit Ca++ influx presynaptically
2. stimulate K+ efflux (hyperpolarize membrane)
Post-Synaptic mechanism that reduces NT release:
Stimulate K+ channel
Describe 2 mechanisms morphine can reduce NT release
Pre-synaptic: morphine binds mew receptor, shutting down Adenylate cyclase/cAMP-mediated Ca2+ influx, effectively reducing NT release.
Post-synaptic: morphine binds mew receptor, promoting K+ efflux-mediated hyperpolarization, shutting down Ca2+ permeability
6 effects of opioids
Euphoria Sedation Cough suppression Miosis Temperature RESPIRATORY DEPRESSION
3 strong opioids
Morphine
methadone
meperidine
moderately strong oipoips
codein
oxycodone
Receptor agonist-antagonist
pentazocine
buprenorphine
antagonist
noloxone
Meperidine’s bioactive metabolite is
norpethidine
Michael jackson
meperidine
key side effect of opioids
suppressed respiration
mechanisms of opioids to produce euphoria?
“inhibiting the inhibitor”
opioids bind mew receptor presynaptically, suppressing GABA release, thus promoting DA release at post-synaptic neuron
weakly antagonizes the analgesics effects of morphine and meperidine (eg. to reduce hallucination)
pentazocine
reverses opioid overdose (respiratory depression)…blue lips…unresponsive to pain…not breathing….
noloxone
methadone
an opioid that reverses effect of morphine…lasts longer….mew and delta type receptor agonist
