final: opiods Flashcards
Spinothalamic Tracts
Major ascending tracts that transmit pain from the periphery to higher centers
Neo-spinothalamic (lateral spinothalamic)tract
Paleo-spinothalamic (medial spinothalamic)tract
pain descending tracts
the peri-aqueduct grey (PAG) matter
-locus coeruleus (LC) andraphae nucleus
prevent the transmission of pain by inhibiting release of neurotransmitters from the primary-order neurons
natural inhibition of pain
spinal interneurons stimulated by 5ht and NA to release endorphins and enkephalins in spinal cord
Opiates inhibit pain at two levels
Opiates inhibit pain at the level of Pain afferents
2-Opioids and cannabinoids are hypothesized to activate descending analgesia through an indirect process of ‘GABA disinhibition’
three families opiate receptors
1- Mu (µ/MOR)
2-Delta (δ/DOR)
3- Kappa (κ/KOR)
sufentanyl
potent fentanyl analogue
Very high affinity for the mu opioid receptor, and low affinities at kappa and delta receptors
reminifentanil
fentanyl deriv
shorter acting
Carfentanil
High affinity opioid agonist with high selectivity for the mu receptor
large animals
codeine, hydrocodone
moderate opiod agonists
NALOXONE
μ-opioid receptor competitive antagonist
NALTREXONE
similar to naloxone but high oral bioavailability
used mainly for long-term treatment of addiction
Methadone
A Mµ agonist used for analgesia and for detoxification or maintenance in opioid addiction
Buprenorphine:
partial agonist is now in widespread use for addiction treatment
meperidine
opposite side effects to other opioids
