Alcohol Flashcards
Three alcohols to worry about
ethanol, ethylene glycol, methanol
What do you give an alcoholic who comes to the ED with withdrawal?
Thiamine + a benzo (lorazepam) + dextrose if comatose
Treatments for alcohol dependence?
Disulfiram, naltrexone, acamprosate
EtOH metbolism
Zero order kinetics. EtOH is converted to acetaldehyde by alcohol dehydrogenase (requires NAD/NADP). Acetaldehyde converted to acetate by aldehyde dehydrogenase
Acetaldehyde effects
N/V, flushing
Why do Asian people’s cheeks turn red with they have a sip of wine?
Asian flush. SNP in aldehyde dehydrogenase. It doesn’t degrade acetaldehyde as quickly, so it builds up.
Disulfiram MOA
Inhibits acetaldehyde dehydrogenase, leads to buildup of acetaldehyde which makes you feel like crap whenever you have a drink.
Naltrexone MOA
Mu antagonist. It decreases reward feeling and craving
Other drugs with disulfiram like effect
Sulfonylureas, cefotetan, ketoconazole, procarbazine, metronidazole
Acamprosate MOA
GABAa agonist / NMDA antagonist. Oral drug
Treatment for tylenol OD?
N-acetylcysteine
Normal acetaminophen metabolism
Sulfated or glucuronidated
Acetaminophen metabolism in alcoholics
CYP2E1 is induced –> increases NAPQI pathway. NAPQI = toxic. NAPQI is eliminated by mercaptopuric acid conjugation. When mercaptopuric acid runs out –> hepatotoxicity from NAPQI
What happens at BAL of <50?
Limited muscle coordination
What happens at BAL of 50-100?
Pronounced uncoordination
What happens at BAL of 100-150?
Mood and personality changes; intoxication over legal limit
What happens at BAL 150-400?
N/V, ataxia, amnesia, dysarthria
What happens at BAL > 400?
Coma, respiratory insufficiency, death
What factors affect BAL?
Vd, BMI, gender. More body water = lower BAL. More fat = higher BAL. Female = higher BAL.
EtOH effect on receptors?
Increase GABA release and receptor density
Inhibits NMDA / upregulated receptors in alcoholics
Increased synaptic DA (increased VTA/NA reward)
Increased ACTH
Increased beta endorphin (activates mu)
Increased synaptic 5-HT
Increased CB1 (modulates DA/GABA/Glu)
EtOH liver ADEs
Decreased gluconeogenesis, fatty liver, cirrhosis, liver failure, hepatocellular carcinoma
EtOH GI ADEs
Bleeding from portal HTN/retching, nutrient deficiency
Fomepizole MOA
Inhibits alcohol dehydrogenase. Allows ethylene glycol/methanol to be excrete unmetabolized
Treatment for methanol poisoning
Fomepizole. (Can also use EtOH as a competitive antagonist)
Treatment for ethylene glycol poisoning
Fomepizole
Effects of ethylene glycol poisoning
Acidosis + nephrotoxicity
Effects of methanol poisoning
Acidosis + blindness (retinal damage)
