Download Slide 1

Drugs
Chapter 7
Drugs
•
•
Hallucinogens – mostly naturally
occurring substances that can change
normal thought processes,
perceptions, and moods.
Stimulants – act on the nervous
system to make the user feel better
and increase his/her energy/alertness.
Drugs
•
•
Narcotics/analgesics – substances
affecting the central nervous system
to relieve pain.
Depressants – a drug that reduces
excitability and calms a person.
Poisons
• Toxicology – the study of the adverse
effects of chemicals or physical agents
on living organisms.
Poison Effectiveness
•
•
•
The chemical form of the substance
(pure arsenic versus arsenic trioxide).
Method of entry (oral versus
injection).
Condition of victim (weight, age,
general health).
Poison Effectiveness
Time period of exposure
• chronic exposure – continuing
exposure over long periods of time
• acute exposure – large dosage at one
time
Poison Effectiveness
Presence of other chemicals.
• synergism – combined effect of
substances that exceeds the sum of
their individual effects.
• antagonism – combined effect of
substances that decrease their
individual effects.
Counteracting Poisons
• Chelating agent – an organic
compound that combines with a metal
to form a ring compound.
Alcohol
• Alcohol is the most abused depressant in the
United States.
• The chemical name for alcohol is ethanol or
ethyl alcohol.
• Ethanol, like all alcohols, is toxic.
• Ethanol effects the central nervous system.
• Alcohol circulates in the blood stream
immediately after consumption.
Alcohol and the Law
• The law is concerned with the level of
blood alcohol content (BAC).
• BAC is expressed as a percent weight per
volume.
• Federal and Kansas BAC limits are both
0.08 percent.
• This means that there is 0.08 grams of pure
alcohol for every 100 mL of blood.
Alcohol Laws
•
•
•
•
•
DUI – driving under the influence
DWI – driving while intoxicated
OUI – operating under the influence
OWI – operating while intoxicated
MIP – minor in possession
Alcohol Processing
• The average person removes 0.015 percent
per hour.
• About 5% of ethanol leaves the body through
respiration, perspiration, and urine.
• About 90% of alcohol is chemically
processed (metabolized) by the liver.
• It is changed first to acetaldehyde (a poison).
• Then it is changed to acetic acid and finally to
carbon dioxide and water.
CH3CH2OH→HCH3COO
HCH3COO →CO2 + H2O
Alcohol & the Liver
Calculating BAC
0.071 (volumedconsumed , oz )  (%alcohol )
BAC male 
bodyweight
0.085  (volumedconsumed , oz )  (%alcohol )
BAC female 
bodyweight
BAC Affects
•
•
•
•
•
0.02 divided attention, slowed reaction time
0.04 Eye movement control
0.05 Coordination
0.06 Judgment
0.08 Concentrated attention, speed control
Breathalyzer Tests
• Henry’s Law - At a constant temperature,
the amount of a given gas dissolved in a
given type and volume of liquid is directly
proportional to the partial pressure of that
gas in equilibrium with that liquid.
• According to Henry’s Law the
concentration of alcohol in the breath is
proportional to the concentration of alcohol
in the blood.
The Chemistry of Breathalyzers
• An orange dichromate ion is reduced to
a green chromium (III) ion.
8H++Cr2O72- +3C2H5OH→
2Cr3++3C2H4O+7H2O