Medicines and
drugs
Stimulants
stimulants
• What are stimulants?
• Examples?
• What medical uses do they have?
stimulants
•nicotine, caffeine, amphetamines
•the intention of these drugs is to have
similar effects to adrenaline (or
epinephrine) which is a natural
stimulant.
•amphetamines (synthetic) 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 acts as messengers and
stimulate pathways which …
• …increases activity of the brain
• largely opposite to depressants which
decrease activity in the nervous system
amphetamines
• group of drugs which mimic the effect of adrenaline
• classified as symphatomimetic drug as it stimulates the
symphatetic nervous system
• adrenaline or epinephrine = hormone released in times
of stress e.g. pain, cold, fear, …
• 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
physiological effects
short term
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increased brain activity
increased heart rate,
increased blood pressure,
increased breathing rate
increased air flow in air
passages
shakes
increased alertness and
concentration
sleeplessness
decreased appetite
long term
 increased risk of heart
disease
 increased blood pressure
 coronary thrombosis
 stomach ulcers.
 tolerance:
 increasing amounts cause
damage/death/overdose/letha
l dose
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 chain (ethyl).
• Different: functional groups
• amphetamines:
• primary amine
• epinephrine:
• 3 hydroxyl groups
• secondary amine
nicotine
• A nicotine molecule contains the following
functional groups: a tertiary amine, benzene ring
structures with nitrogen atoms in them
(=heterocyclic rings).
• Nicotine increases levels of adrenaline in the brain
physiological effects nicotine
short term effects
 increased heart
rate
 increased blood
pressure
 reduced urine
output
 increased
concentration
long term effects
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increased risk of cancer or stroke
heart disease / thrombosis
stomach ulcers
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 psychoactive
stimulant (=acts on CNS).
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
• benzene rings containing both carbon
and nitrogen atoms (heterocyclic rings)
• tertiary amine group
• two amide groups (- N – C = O)
caffeine
consumption in small
amounts
• increased mental
alertness
• greater ability to
concentrate
•diuretic; dehydration
large amounts
•can cause anxiety,
irritability, nausea
•dependence