Alcohol Flashcards
Alcohol- MOA
Increases duration of GABA channel opening and acts at GABA/ Cl.
Acts on other NT’s receptors, and disrupts membrane fluidity
Alcohol absorption
passive diffusion in stomach but mostly in the SI.
Affected by food, gastric rate, and concentration
Alcohol distribution and BAC
Distributes through all of the body water
BAC therefore depends on BW: M vs F, young vs old, weight, dehydration
What BAC corresponds to psychomotor impairment
.1
what BAC is the legal limit
.08
What happens at BAC .3-.4%
alcohol becomes as strong as a surgical anesthetic
What order kinetics is alcohol metabolism?
Why?
zero order- alcohol metabolism is independent of concentration and time
Even a small amount of alcohol saturate the receptors
What system/s metabolize alcohol
Both in liver
alcohol dehydrogenase system
CYPP450 (microsomal) ethanol oxidizing system- this system causes lots of drug interactions
Describe the alcohol dehydrogenase pathway
EtOH –> acetaldehyse via (Alcohol dehydrogenase
acetaldehyde –> acetate via aldehyde dehydrogenase
Acetate is broken down to CO2 and Water via metabolism which provides calories –> dec appetite –> nutrient deficiencies
CNS side effects of alcohol
dec inhibitions
reduces REM sleep
respiratory depression
coma/death- linear slope from anesthesia to death
Process of alcohol intoxication that leads to death
Inhibitions dec –> Anxiolytic –> sedation –> hypnosis –> anesthesia –> respiratory depression –> coma –> death
most alcohol related deaths are from the respiratory depression
Non CNS effects of Alcohol
cutaneous vasodilation resulting in flushing and feelings of warmth but actually heat loss. At higher doses leads to HTN, cardiomyopathy, arrhythmias, and can be fatal
Inhibits ADH –> diuretic
moderate amounts improve lipid profile
Appetite- large amounts suppress apetite –> nutrient deficiencies ie Korsakoff and wernicke (thiamin and niacin)
Liver- dose dependent toxicity- fatty change leads to hepatitis, cirrhosis, and hepatic failure
pancreatitis can be fatal
Gout exacerbation
Hyperestrogenemia
Emesis and other GI issues
Fetal alcohol syndrome
Alcohol and drug interactions- mechanism
in the beginning it is a CYP450 inducer dec drugs metabolized by this system.
As liver damage progresses that system slows down
Signs of Fetal Alcohol syndrome
microcephaly
mental retardation
abnormal- face, joints, and heart
Alcohol tolerance
pharmacokinetic tolerance= more efficiently metabolized
pharmacodynamic tolerance= less sensitive to the drug
Behavioral tolerance= learn how to not act drunk when you are
What two issues are caused by B1 deficiency
Thiamine deficiency results in Wernikes and Korsakoff encephalopathy
Wernikes encephalopathy
reversible
ataxia, opthalmoplegia, confusion
Korsakoff encephalopahty
Irreversible
apathy, antero and retrograde amnesia, confabulations
What are the signs of hyperestrogenemia
gynecomastia
Testicular shrinkage
Emesis issues with alcohol
Mallor Weiss tear
Boerhaave syndrome
aspiration
GERD
Withdrawal- alcohol
starts 6-24 hours after last drink
last 5 days
characterized by irritability, insomnia, tachycardia, palpitations, hallucinations, delirium, tremors, grand mal seizures, arrhythmias
seizures and arrhythmias can be deadly
Alcohol withdrawal treatment
benzos- diazepam, lorazepam, oxazepam- work on same receptor. oxazepam and lorazepam are not dependent on hepatic metabolism (preferred bc alcoholics may have liver damage.
phenytoin- control seizures
betablockers, clonidine- control autonomic effects
vitamins and thiamine for nutrient deficiencies
do you give antipsychotics in alcohol withdrawal
NO!, inc seizures
Drugs to give after alcohol withdrawal has subsided and now patient is focused on kicking the addiction
Disulfram –> block acetaldehye dehydrogenase causing a buildup of acetaldehyde –> flushing, HA, N/V, hepatotoxicity
Naltrexone- long acting opiod agonist- reduces cravings, cause hepatotoxicity
Acamprosate- dec cravings to help maintain abstinence, may act on GABA receptors. Less potential for hepatotixicity.
Naltrexone + acamprosate work well together and are better than either one alone
