drugs of abuse- cocaine/nicotine Flashcards
types of cocaine
paste (powder from the plant), or cocaine HCL (ie powder in acidic solution)- IV, snort, or eat crack ie with alkaline solution given via inhalation ie smoking
administration of cocaine- IV vs inhalation
same speed of onset in IV vs inhalation, but amount of cocaine more in blood than inhalation because cocaine has high pKa, so more ionised in acid conditions- thus in stomach (ie oral route) it’s ionised, and in cigarette smoke (also acidic ie inhalation) also ionised, so less BIOAVAILABLE
metabolism of cocaine
most broken down by liver cholinesterates into INACTIVE metabolites, OR in blood by plasma cholinesterases thus due to this combination has short half life of an hr- contributes to addictive nature
DIAGRAM use of cocaine and why+ dose
local anaesthetic- blocks sodium channels outside membrane pH higher ie closer to Pka, so more unionised, so more can get into membrane inside membrane pH lower, so more ionised ie charged, so can interact better with target ie channel as more reactive high dose used for this
cocaine pka and solubility
cocaine is alkaline with high pka, thus lower pH= more ionised
effect of cocaine on NA/dopamine/serotonin+ dose+ therefore use
leads to reuptake inhibition, as inhibits MAO-A, thus less NA broken down lower dose for this- blocks dopamine transporter, so less DA reuptake, so more left in synapse, so more projection from VTA to NA
other effects of cocacine
moderate effects are usually positive ie more energy, euphoria, talkative, but severe effects ie at high dose are negative ie anxiety, aggression etc
cardiovascular effect of cocaine and mechanisms
can lead to MI- increases NA and overall SNS= more HR/contractility and vasoconstriction= potential endothelial injury, as well as higher O2 heart DEMAND SNS also activates platelets= atherosclerosis= lower O2 heart SUPPLY Na+ transport goes down= less LV function, and inflammation as well these combined= potential MI
effectof cocaine on hyperthermia including body responses
overdose leads to muscle contraction, too much CNS activity (agitiation) and locomotor activity, which all increase body temp this combined with a hot environment eg clubbing= hyperthermia body normally responds by increasing sweat and peripheral vasodilation, but cocaine prevents this
whats in cigarette smoke
most VOLATILE (gases like nitrogen, CO), some PARTICULATE, which contains nicotine (alkaloids) and tar
types of nicotine, administration and absorption
spray (intranasal) gum (absorb through mucous membranes of mouth) cigarettes- inhalation, more nicotine than previous methods nicotine patch- contains most nicotine: best absorption
speed of onset of different types+ importance
cigarette highest, patch very slow across long period of time, spray/gum in middle cigarette also broken down quickly= addictive
metabolism of nicotine
broken down quickly into inactive metabolite- thus like cocaine short life , but NT broken down in blood
mechanism of nicotine
effects NICOTINIC receptor in VTA, which activates dopaminergic neurone= more dopamine released from NA=euphoria
CVS risk of nicotine
like cocaine, increases NA (as enhances nicotinic receptor) and SNS, leading to increased HR/BP/platelets etc= heart problems ALSO increases LDL, increasing risk of atherosclerosis
