Alcohol Flashcards
Alcohol
Ethanol - hydroxyl group
properties of ethanol
water soluble = crosses membranes
small
polar + non-polar regions
sugar sources
beer, scotch, whiskey - grains
gin, vodka - potatoes
rum - molasses
tequila - agave
brandy - fruits
Pharmacokinetics
Drug interactions with the body
absorption
EtOH is mostly absorbed in the small intestine (not altered by stomach’s low pH)
food = slows absorption (lower peak BAC)
distribution
distributed through tissue (especially aqueous)
greater body volume and greater water volume (larger and leaner) = lower BAC
rapidly distributed (small molecule) = quick rise in BAC
acute effects
brain - decreased judgement, decreased anxiety, increased emotions, increased aggression
circulation - dilated blood vessels in skin (autonomic response), decreased blood clotting
disturbed neural connections that facilitate REM = less REM sleep
suppressed hippocampus = blackout drunk
metabolism
zero order kinetics = linear elimination curve: the amount of ethanol eliminated is constant per unit time, regardless of plasma concentration
biphasic: 1. BAC rises = stimulant 2. BAC declines = depressant
Mechanism
interacts with brain receptors = changes neurophysiology
EtOH modulates glutamate and GABA receptor activity
reduced electrical activity: at higher concentrations = inhibition of glutamate NMDA-voltage gated Ca2+ channels, at lower concentrations = strong potentiation of GABA-A
= neuronal inhibition (through hyperpolarization after neuronal activation)
lethal doses = asphyxiation by shutting off brainstem
GABA-A receptors
cys-loop ligand-gated channel
heteropentameric receptors
hyperpolarize cells - conduct negative chloride current into neurons
NMDA receptors
ionotropic glutamate receptor
heterotetrameric receptors
depolarization - conduct positive currents into neurons
Addiction
EtOH increases rate of firing in dopamine pathway = increased dopamine release
= increased inhibition of GABA interneurons + decreased stimulation of glutamatergic GABA interneurons = disinhibition
= more dopamine
physiological effects
autonomic - vasodilation = warm skin but decreased core temp
loss of stomach mucosal lining - ulcers
spins: EtOH permeated inner ear - when BAC decreases, it diffuses out of cupula first, making it more dense than the endolymph - sensory fibers perceive it as motion
Tolerance
presence of alcohol = upregulation of enzymes in liver
the more you drink, the more you can drink
long term effects
liver - fat deposits = cirrhosis
brain - cell death
cancer
