Medicines and
drugs
Stimulants
stimulants
•nicotine, caffeine, amphetamines
•the intention of these drugs is to have
similar effects to adrenaline which is a
natural stimulant.
•amphetamines can do this because they
have similar structures to adrenaline.
stimulants
• affect central nervous system; act on the level of
neurotransmitters which are chemicals that act as
messengers and stimulate pathways which …
• …increases activity of the brain
• Relax air passages and help facilitate breathing (treat
bronchitis)
• Reduce appetite
• largely opposite to depressants which decrease activity in
the nervous system
physiological effects
short term
 increased heart rate, blood
pressure, breathing rate
 dilation of pupils
 constriction of arteries
 sweating
 decreased appetite
 stimulating effects
 increased alertness and
concentration
long term
 increased risk of heart
disease
 increased blood pressure
 coronary thrombosis
 stomach ulcers
 tolerance
 increasing amounts cause
damage/death/overdose/letha
l dose
The last one is psychological
amphetamines
• group of drugs which mimic the effect of epinephrine
(adrenaline)
• classified as sympathomimetic drug as they mimic the effects of
epinephrine
• adrenaline or epinephrine = hormone released in times of stress
e.g. pain, cold, fear, … “fight or flight”
• response to increased adrenaline in the body:
•
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increased heart beat/blood pressure
Increased blood flow to brain and muscles
Increased air flow to lungs
Increased mental alertness
compare
• Common: both amphetamines and epinephrine have
a phenyl-ethyl-amine chain which consists of a
benzene ring linked to an amine group by a carbon
Change the
chain
• Different: functional groups
• amphetamines:
• primary amine
NH2 to CH3
And you have
Meth.
amine
ethyl
• epinephrine:
• 3 hydroxyl groups
• secondary amine
phenyl
(benzene
With one
Less H due
to side chain)
nicotine
• A nicotine molecule contains the following
functional groups: a tertiary amine, aromatic
benzene ring structures with nitrogen atoms in
them, and double bonds (alkene functional group).
It is lipid soluble so it can cross the blood –brain barrier bringing rapid effects on
brain activity. Increases levels of adrenaline and alters concentrations of neurotransmitters.
physiological effects nicotine
short term effects
 increased heart
rate
 increased blood
pressure
 reduced urine
output
 Stimulating effects
(increase
concentration,
relieve tension,
counter fatigue)
long term effects
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Increase risk of heart disease
Peptic ulcers (esophagus or stomach)
Coronary thrombosis (blood clot in
coronary artery)
increased risk of cancer or stroke
emphysema
bronchitis
shortage of breath
coughing
bad breath
yellowing of teeth or fingers
adverse effect on pregnancy
addiction to tobacco
reduction in capacity of blood to carry
oxygen;
withdrawal symptoms / weight gain (on
quitting);
caffeine
• Caffeine is a respiratory
stimulant. When
consumed in large
amounts it can cause
anxiety, irritability and
sleeplessness. It is a weak
diuretic i.e. causes the
body to lose more water
than it takes in
• Its structure is similar to
nicotine.
structure of caffeine
• aromatic rings containing both carbon
and nitrogen – (like nicotine)
• tertiary amine group
• two amide groups (- N – C = O)
Caffeine
Nicotine
*don’t use
methyl groups
as similarity
caffeine
consumption in
small amounts
•Burn energy faster
•increased mental
alertness
• greater ability to
concentrate
•diuretic; dehydration
large amounts
•can cause anxiety,
irritability, nausea
•headaches
•insomnia
•dependence