WK 4: mental health Flashcards
opiate toxicity treatment
naloxone
what happens to codeine in the body
prodrug metabolised to morphine
what metabolises codeine
CYP2D6
what happens to subjects who are ultra-rapid metabolizers based upon CYP2D6
higher than expected Morphine levels -an initial overdose with more SE and shorter duration of pain control
what can happen in an ultrametabolizer mother who is breast feeding and prescribed codeine
infant death
why can genotype CYP2D6 vary the metabolism of codeine
it is highly polymorphic
other opiates that are affected by genetic polymorphism (3)
hydrocodone
oxycodone
tramadol
tramadol and its active metabolite effect=
bind to mu opiate receptors in CNS causing inhibition of ascending pathways, altering pain pathways and perception of pain
+inhibits NE and 5-HT reuptake -descending pain pathways
why is tramadol affected by polymorphism
as one pathway for its metabolism is oxidation via CYP2D6 to a much more active metabolite
systemic effects of ultrametabolizer and tramadol
greater analgesia
stronger miosis
higher incidence of nausea
what enzyme metabolises thiopurine drugs (azathiopurine)
Thiopurine methyltransferase (TPMT)
what does enzyme TPMT*3 mutation mean
extremely low activity
low activity of TPMT*3 –>
risk of myelosuppression is increased
