Alcohol and Hypnotics Flashcards
How long does it take for alcohol to be absorbed from the gut?
peak in 40 minutes on an empty stomach - supa fast
What is the optimum concentration for bioavailability?
20% EtOH
What is the volume of distribution of alcohol? Where does it distribute?
.7L/kg, easily goes to all tissues
Where is alcohol metabolized?
In the liver, but some in the gut (especially in men)
True or False: Alcohol is metabolized via first order metabolism.
False! Zero order, i.e. a fixed amount per unit time
Does alcohol have a half life?
No
What are the two metabolites involved with alcohol?
alcohol dehydrogenase, aceetaldehyde dehydrogenase
What is the principle metabolite? Is it toxic? What is it broken down into and where?
acetaldehyde-toxic. further broken down in liver to acetate
What are the acute CNS effects of alcohol (2)?
1) continuous CNS depressant
2) anticonvulsant in amounts that cause general CNS depression
Alcohol causes continuous CNS depression, just like ___ and ___
general anesthetics and barbiturates
which part of the cortex is depressed at low concentrations?
those involved in highly integrated functions
what causes the “stimulant” effects of alcohol?
depression of inhibitory control mechanisms
what succeeds the initial phase of alcohol?
general impairment of nervous function. muddled thoughts and awkward movements
what is caused by high concentrations of alcohol?
general anesthesia
What determines the CNS effects?
proportional to the concentration of alcohol in the blood
What follows the anticonvulsant properties of alcohol?
followed by a long period of hyperexcitability
What are the consequences of the hyperexcitability period?
alcohol is contraindicated in epilepsy and alcohol withdrawal in heavy users may cause seizures
alcohol + which drugs can cause enhancement of CNS depression?
sedatives, hypnotics or tranquilizers
What else can alcohol be used for?
topical antiseptic and astringent (not for sterilizing)
What does alcohol do to respiration?
response to CO2 is depressed- can be dangerous
What does alcohol do to the GI tract? In who is it therefore contraindicated?
increase in gastric juices: contraindicated in peptic ulcer
what does alcohol do to the kidneys?
diuretic, inhibition of ADH
what does alcohol do to the liver?
accumulation of fat: increased NADH/NAD ratio + mobilization of fat from peripheral tissues
What does alcohol do to the CV system?
vasodilation. no significant until severe intoxicating levels are reached
Physical dependence?
yes
What does metabolic tolerance mean?
increased metabolism and inducible enzymes in liver. alcoholics will have cross tolerance with barbiturates
What does functional tolerance mean?
changes the dunctional properties of many membranes (changes lipid environment of cell membranes). chronic alcohol leads to more rigid membranes, therefore more alcohol for same effect
What does functional tolerance lead to?
dependence (withdrawal)
what does behavioral tolerance mean?
recovery of ability to funtion socially in spite of the drug. can also refer to how others perceive the drug user
What are the consequences of dependence?
abstinence syndrome, “purposeful behavior”
What is alcoholism?
tolerance + physical dependence + withdrawal avoidance
How do you treat alcoholism acutely?
Benzodiazepines to “taper off” over weeks. prevent respiratory failure, prevent seizures and arrhythmias during withdrawal
How do you treat alcoholism chronically?
behavior modification, Disulfram for aversive therapy (prevents metabolism of acetaldehyde), Naltrexone = opiate antagonist
What’s up with methanol?
misguided ethanol substitute that has very toxic breakdown products.
What do you use to treat methanol poisoning?
ethanol and dialysis
