drugs of abuse- COCAINE AND NICOTINE Flashcards
where is cocaine extracted from?
from the leaves of the Erythroxylum coca plant
what are the pharmacokinetics of cocaine?
cocaine is rapidly metabolised to inactive metabolites
plasma and liver cholinesterases can also metabolise it
effects of cocaine dont last for long
this contributes to the addictive potential of the drug
what makes cocaine particularly addictive?
eurphoric association with rapid onset of action
rapid metabolism so try to take more to restore euphoric effect
what are the effect of cocaine in the body
local anaesthetic-
blocks sodium channels so reduces neural activity at site
blocks the NA reuptake exporter - more of the NT in the synapses so enhances the dopaminergic/NA/serotinin effects
what is the significance of ionisation of a drug
want a drug to be unionised in blood stream so that it can enter target tissue easier
once it is at its target it is better if it is ionised because then it has a more potent effect
what does cocaine do to the dopamine affinity and efficacy for the dopamine receptor?
it doesnt change either
all it does is increase the number of NTs in the synapse but doesnt affect the ability for the molecule to bind and does not `affect the affect of the NT on the receptor
how does cocaine cause euphoria?
dopaminergic neurones project from the ventral tegmental area to the nucleus accumbens
these dopaminergic neurones secrete dopamine which binds to the dopamine receptor and produce a feeling of euphoria
cocaine blocks the dopamine reuptake exporter to the euphoric effects are increased
how can cocaine produce hyperthermia
increases locomotor activity, inc agitation, inc involuntary muscle contraction which will all increase body temperature
if this is combined with an hot environment such as club then this can cause hyperthermia
how is nicotine administrated and their dosages?
nicotine spray 1mg
nicotine gum 2-4mg
cigarettes 9-17mg
nicotine patch 15-22mg
which is the best method for bioavailability of nicotine?
nicotine patch has about a 70% bioavailability.
cigarettes have a 20% bioavailability
why is cocaine metabolised faster then nicotine?
because cocaine can be metabolised in the blood, nicotine cannot
nicotine still has a very fast metabolism
how does nicotine work?
stimulates the nicotinic acetylcholine receptors
directly stimulates the dopaminergic neurone which triggers the euphoric pathway
what are the positive uses of nicotine?
There is evidence that nicotine actually protects against Parkinson’s disease, as it increases brain cytochrome
P450, which metabolise a lot of neurotoxins in the brain.
It is also protective against Alzheimer’s disease, as
nicotine decreases β-amyloid toxicity and the build up of amyloid precursor proteins (APP).
