anaesthesia drugs and L-dopa Flashcards
anaesthesia
muscle relaxation
muscle relaxants are
NMJ blockers - prvemt normal action of ACh
two types pf actions of muscle relaxants
depolarising and non polarisation
depolarising
e. g. succinylcholine
- 2 ACh joined together- antagonistic to AChr
- causes constant depolar
what metabolises succinyl choline
AChE
Non-depolarising
- curare derivatives
- prevents ACh binding to the receptor
Opioids signal via
Gi/Go
Opioids and Gi/Go
- decrease conc of cAMP
- decrease conc of PKA- less phosphorylation of VOCCS
- potassium channels open
- less depolarisation
analgesia
inhibiting the feeling of pain
three opioid receptors
mu, delta , kappa - all responsible for diff roles
examples of opioids
codeine, diamorphine, tramadol
how do opioids prevent pain in dorsal horn
inhibition down from the brain to the spine
where do opioids work
site of injury- prevent inflammatory mediators from being released (allodynia)
ketamine
IV anaesthesisa
- antagonises NMDA receptors
- stopping glutamate from being excitatory
- causing inhibitory state
Propofol/ thiopental
- IV
- Hypnosis effect
- activates GABAa receptors
Propofol and GABAa
opens Cl- channels- hyperpolarisation- reduced excitability
anticonvulsant drug
used for treatment of neuropathic prom
-enhanced GABAa
- also blocks sodium/ calcium channels
- reducing the release of excitatory glutamate
local anaesthetic
produced anaesthesia by inhibiting excitation of nerve ending or by blocking conduction in peripheral nerves
- achieved by reversibly binding to sodium channels- voltage gated
- decreasing rate of depolarising and repolarisation
local anaesthetic binds more readily
to activate Na+ channels- therefore neuronal blockade is fast in rapidly firing neurones
STATE DEPENDENT BLOCKADE
seratonin
lack contributing to mood problems
-metabolised by MAOI
negative of MAOis
associated with high BP
L-dopa
dopamine is hydrophobic so cannot pass BBB
- L dopa used to treat parkinsons, to help increase control of movement due to death of DA neurones
carbidopa
prevent l-DOPA from being converted to dopamine in the periphery
COMPT inhibitors
prevents LDOPA from being converted to 3-O-mehtyldopa
DCC
converted LDOPA to dopamaine
MAO-B
converts dopamine to useless metabolites
MAO-Is
selegilline
- prevents MAO from converting dopamine to useless metabolites
Deep brain stimulation
a neurosurgical procedure where neurosimulator is implanted into he brain
-send s electrical impulses through implanted electrodes to specific targets in the brain
–> increases blood flow and therefore availability of NT
antipsychotic
excess dopamine is associated with schizophrenia
- these drugs have a high affinity for dopamine receptors
- no depolarisation
- can lead to symptoms of parkinsons
