Drugs Flashcards
Mechanisms by which nerves inhibit NT activity
Uptake at pre/post junctions, metabolism intracellular or in synapse, or receptors on pre-junction to inhibit release
How does Cocaine work?
Will inhibit NA re-uptake, will also inhibit Na+ channels, Dopamine (dependence) and serotonin (depression) reuptake
How does Methamphetamines and ephidrines work?
Promote non-exocytotic release of NA
What is the catecholamine production pathway
Tyrosine to L-DOPA via tyrosine hydrxylase, then to dopamine by dopa decarboxylase, then to NA by dopamine b-hydroxylase then to Adrenalin by PENM transferase
Roles of Dopamine
Movement (Parkinson’s), behaviour (Schizophrenia), Dependence in the nucleus accumbens in basal ganglia and ventral tegmentum in brainstem, Pituitary function (pro-lactin function)
What was the first anaesthethic
Cocaine applied topically to the eye
Different definitions of Locaal and general anesthetic and analgesia
Analgesic - target pain and sensory pathways if pain
Local anaesthetic - regionalised inhibition of pain/sensory pathways
General - LOC, not regionalised, depresseses CNS effects of pain
What are the mechanisms local anesthetics and some common ones
Short acting - procaine
Long acting - lignocaine, bupivicaine and ropivicaine
Other - Benzocaine
Lignocaine is lipophobic and must be deprotonated to cross the membrane, will then have a H+ added before it can inhibit the Na+ channel. Benzocaine is hydrophobic and therefore will cross the membrane and act on Na+ channels. Hence Benzocaine is quicker acting. Binds to S6 region of domain IV intracellularly
What is the selectivity of Local anesthetics? and why?
Sensory>ANS>Motor due to the size of neuron
Dose dependent side effects
Cardio and respiration can be compromised, hypersensitivity isn’t dose dependent
What are some commonly used general anestetics
Propofol and thiopentate via IV
What is the thought process behind epilepsy treatment
® Benzodiazepines will incrase GABA receptor activity
® Phenytoin will inhibit Glutamate
® Ethosuximide (inhibits Ca2+ T-type channel)
® Inhibit NMDA receptor (Felbemate)
Ultimately increase inhibitory and decrease excitatory signals
What is the effect of phenytoin
Will Inhibit Na+ channels an prevent the release of glutamate
What is the action of Benzodiaziopines
Will enhance the GABA A ion channel excitibility to GABA and increase the rate of Cl- channel opening
Describe the action of barbituates
Will cause the constitute opening of Cl- channels, easier to overdose than benzodiazipines
