Drugs in Our Society
What is a drug?
n Any
chemical which causes a change in the structure and/or function of living
tissue
n Pharmacology:
the study of how drugs change living systems
Types of Drugs
n
Prescription
drugs: administered by a physician
n brand name: manufactures name
n generic name: common name
n
Over the counter
drugs: no prescription needed
n
legal or social
drugs
n
ex. Caffeine,
nicotine, alcohol
n
Illicit or street
drugs
n
ex. LSD, PCP,
heroine, cocaine
n
Misc. substances
n
ex. Glue,
gasoline, paint
Effects in General
n Depend
on :
n set:
expectation
n setting:
environment
n motivation
n Drugs
can:
n change
the endocrine system
n replace
hormones, inhibit hormones
n change
the nervous system
n mimic,
inhibit, or prevent neurochemical transmission
Make up of Drugs
n Drugs
are often combined with other ingredients
n diluents
and solvents: expand size
n sweetners,
flavors, dyes: make more palatable
n preservatives
and stabilizers: increase shelf life
n sterile
dosage forms: make quantity and quality uniform
Make up of Street Drugs
n Usually
combined with sugar, talc, or other unknown drugs
n quantity
of drug is extremely variable
n can
contain by-products of chemical synthesis
n NEVER
STERILE
Drug Travel in the Human Body
1. ABSORPTION:
n
ORAL: slow
n absorbed through
the small intestine
n full stomach will slow absorption
n goes to the liver once absorbed
n some drugs are destroyed by acidic stomach
n
TOPICAL: skin
n
INJECTIONS:
n INTRAVENOUS: most rapid effect (~16 sec), skips
absorption step
n INTRAMUSCULAR OR SUBCUTANEOUS:
n Slower than IV, good for drugs that react to stomach
acid
n
INHALATION:
n fast absorption (8 sec) due to large surface area
Drug Travel in the Human Body
2. DISTRIBUTION:
n blood carries drug throughout body
n drug can leave blood and go into tissues
Drug Travel in the Human Body
3. METABOLISM:
n breakdown of drug
n broken down by liver enzymes
Drug Travel in the Human Body
4. ELIMINATION
n Kidneys in the form of urine
n Bile
Classification of Drugs
n Based
on effect on body
n consists
of a continuum of stimulants and depressants
The Stimulants
n Effects:
n euphoria
(feeling of well being)
n anxiety
n muscle
tremors
n convulsions
n Examples:
n nicotine,
caffeine, cocaine, convulsants (strychnine)
The Depressants
n Effects:
n initial excitement
n tranquility
n sedation
n sleep
n unconsciousness
n death
n Examples:
n general
anesthetics, alcohol, barbiturates, anti-anxiety drugs, anticonvulsant drugs
Common Drugs
n Caffeine:
n usual
sources - coffee beans, tea leaves, cocoa beans
n amount
found in some products:
n brewed coffee = 80-150 mg per 5 oz. cup
n decaf coffee = 2-4 mg per 5 oz. cup
n tea = 30-75 mg per 5 oz. Cup
n Coca-Cola = 34 mg per 12 oz.
n Mt. Dew = 52 mg per 12 oz.
n Vivarin = 200 mg per tablet
Caffeine:
n acute overdoses:
n10x
dose of 1 cup of coffee = restlessness, increased heart rate, difficult
sleeping
n100x
dose of 1 cup of coffee = seizures
n normal effects:
nincreases
alertness, increases muscle capacity to do work, increases urine formation
(diuretic)
COCAINE
n
Source: coca
shrub (leaves contains 1% cocaine)
n
History:
n
South American
Indians chewed leaves (500 AD)
n
became popular
drug in US in 1960’s
n
Pharmacology:
n
blocks pain to
brain in local area
n
short acting
n
euphoria, mood
elevation
n
reduction of
fatigue
n
constricts blood
vessels
n
increases heart
rate and blood pressure
n
Overdose:
seizures, occasional heart stoppage, irregular rapid heart beat, damage to
heart tissue
n
Chronic use:
psychological dependency
MARIJUANA
n
Annual plant that
has various strains
n
THC content
depends on plant:
n
whole plant =
.02%-2% THC
n flowers = 10-15%, leaves = .5-5%, stems = .1%
n
resin = 3%-20% THC
n
hashish/oils =
10-90% THC
n
Routes of
administration:
n
inhalation (50-60%
of THC is lost)
n
oral
n
Absorption:
n
in lungs - 100%
absorbed
n
stomach - 50-80%
absorbed
n
Metabolism: lasts
28-56 hours, traces remain for weeks
n
Excretion: urine
and feces
MARIJUANA continued
n
Effects of body:
n
redness of eyes,
dryness of eyes
n
no effect on
pupil size
n
increase heart
rate
n
no effect on
glucose levels
n
cancer of lungs
(50% more tar than cigarettes)
n
inhibits vomiting
(cancer patients)
n
tolerance
n
effects recall
and time perception
n
driving
(overestimation of speed)
n
anti-motivational?
n
Decreases hormone
levels and sex drive
TOBACCO
n
55 million
Americans smoke; 350,000 will die this year
n
There are over
2000 chemicals associated with smoke
n 1,290 flavorants
n
the major drug in
tobacco is nicotine
n
burning tobacco
produces carbon monoxide
Effects of Tobacco
n
Constricts blood
vessels in skin
n
causes wrinkles in
time
n
increases heart
rate and blood pressure
n
increases oxygen
need to heart
n
decreases skin
temperature due to the decreased oxygen going to tissues
n
lungs:
n
chronic
bronchitis, emphysema, shortness of breath, and cancer (20 pack year = 1-2
packs/day/20 years)
n
decreases hunger
n
increases
spontaneous abortions
n
decreases birth
weights
n
increases death
rates of fetuses
ALCOHOL
n TYPES:
nmethyl
- wood alcohol
nethyl
- grain alcohol
nisopropyl
- rubbing alcohol
npropylene
glycol - antifreeze
Alcohol continued
n Alcohol
dependence is 2nd only to nicotine
n 14
million drinkers in the US
n 50%
of all highway deaths are alcohol related
n 64%
of homicides are alcohol related
n 34%
of rapes are alcohol related
Alcohol continued
n
Absorption:
n
mainly from the
intestines
n
changes with
food, rate of consumption, and concentration of alcohol
n
Distribution:
n
follows body
water
n
crosses brain
barrier and placental barrier
n
Metabolism:
n
alcohol =>
acetaldehyde => calories
n
the liver can
handle 1 drink/hour
n
Excretion:
n
2-5% through the
breath
n
carbon dioxide
and water
Alcohol continued
n
Effects:
n
dilation of blood
vessels
n
increased urine
production
n
inhibits sexual
performance
n
sleep inducer
n
Hangover:
n fatigue, nausea, headache, sound sensitivity
n accumulation of acetaldehyde and congeners
n dehydration
n tissue damage
n long term: liver damage
n fatty liver - reversible
n hepatitis - flu like symptoms
n cirrhosis - liver cells die and develop scar tissue