Alcohol Flashcards
What is the compound known as drinking alcohol?
Ethanol
What is the most commonly detected and litigated drug in criminal cases?
Alcohol
Give examples of cases in which alcohol may play a role.
SA
Homicide
Assault
Impaired driving
What type of investigations does alcohol play an important role in?
Death
What units of measurement is blood alcohol concentration commonly reported in?
mg of alcohol in 100 mL of blood (mg/100 mL)
Often: 0.08g/100 ml
(numbers are just an example)
What is the legal BAC limit?
80 mg/100 mL
i.e., 0.08 g/100 mL
How does ethanol absorb?
By diffusion
What organs absorb ethanol?
25% through stomach, remainder through small intestine
What influences the rate of alcohol absorption?
Type of beverage and presence of food in stomach
How does food in stomach effect ethanol absorption?
Prolongs gastric emptying time (i.e., opening and closing of pylrous valve)
This delay will result in a lower peak BAC
Which organ primarily metabolizes alcohol?
Liver
How much of an ingested dose of alcohol is metabolized? What happens to the remaining amount?
96-98% metabolized
2-4% excreted in urine, breath and sweat
What is the primary enzyme responsible for alcohol metabolism?
Alcohol dehydrogenase
When might the rate of elimination of alcohol not remain constant?
If drinking pattern changes over long term (i.e., alcoholics)
Who are higher rates of alcohol metabolism observed in?
Chronic drinkers
What is the average elimination rate used for forensic purposes?
10-25 mg/100 mL/hour
Describe the pharmacological action of alcohol.
Simple molecule that readily crosses cell membrane including blood-brain barrier
Has specific and non-specific effects on CNS
Non-specific effects due to disturbing proteins in cell membranes
List the 3 non-specific effects of alcohol on neuronal membranes.
- Disturbs relationship of protein in membrane ‘2. Interacts with polar heads of phospholipids
- Alters lipid composition
List the 4 specific effects of alcohol on neuronal membranes.
- Acts at neurotransmitter binding site
- Modifies gating mechanism inside channel
- Interacts directly with channel protein
- Stimulates Gs, which is linked to adenylyl cyclase
What neurotransmitter systems does alcohol affect?
Virtually all
Describe the specific effects alcohol has on some neurotransmitters at lower concentration
Increases inhibitory effects of GABA receptors
Inhibits glutamate receptors
i.e., increases inhibitory transmission, decreases excitatory
Increases 5-HT neurotransmission
Stimulates DA transmission in the mesolimbic pathway
What effect does alcohol have on the CNS?
Is a CNS depressant
What is the initial effect of alcohol?
Disinhibition
What happens to the effects of alcohol as BAC increases?
Increase
Which correlates well with BAC - impairment or gross physical signs of intoxication?
Impairment
What does intoxication refer to?
Visible signs of drunkenness