lecture 11 Flashcards
procaine and tetracaine are what kinds of LA?
esters
lidocaine, mepivicaine and bupiviciane are what kind of LA?
amide
procaine DOA
short
first discovered LA?
cocaine
what blocks reuptake of amines?
cocaine
LA must diffuse into what?
systole of the neuronal axon
benzocaine what is it? and is its solubility high or low?
topical ointments, low
what is an agent without terminal amino group?
benzocaine
aromatic ring shows what?
lipophilicity
amine group shows what?
hydrophilicity
explain the biotransformation for each kind of LA.
ester deesterification in pasma and tissue by pseudocholinesterase. amides dealkylation by CYP450 in liver
anesthetic interacts with what subunit in the pore?
alpha
how many repeat transmembrane domains in alpha subunit?
4
each domain in alpha subunit how how many membrane spanning segments?
6
____ movement increase permeability to ions
s4
LA bind to what segment and domain?
S6 , 1, 3, 4
distribution into the nerve fiber is increase by ______ pka
lower
distribution into nerve fiber is decreased by what?
low PH because more drug is protonated
the larger the diameter of the fiber, the more/less sensitive to the LA
less
in myelinated fibers, how many nodes need to be blocked to inhibit impulse propagation?
3
order of nerve blockade?
small myelinated, small unmyelinated, large myelinated, large unmyelinated
order of loss of function?
pain, temp, touch, proprioception, skeletal muscle tone
are fibers who fire more often more or less effected by LA?
more, easier to bind
adverse affects of LA
cns effects ( tremor, restlessness, convulsions), cardiac effects ( decreased automaticity, myocardial depression), vascular effects (arteriolar relaxation)
risk of hypersensitivity reactions with what type of LA? and why?
ester because of PABA
LA injected into CSF in the subarachnoid space of the spinal canal?
spinal block. risk of transient neurological syndrome
LA injected outside dura? between dura and periosteal lining of spinal canal
epidural block. slower and lower than spinal block
an epidural block in which needle inserted the lowest into caudal block
caudal block
