Stimulants

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Stimulants

• PHS

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Stimulants

• Stimulants are chemical substances that enhance
  the activity of the brain and the central nervous
  system.
• They cause increased alertness and wakefulness.
  In many cases they also act to decrease appetite.

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Sympathomimetic Drugs

• Sympathomimetic drugs are chemical substances
  that mimic the effects of the hormone, adrenalin.
• Generally they cause constriction of the arteries
  and increase metabolism.

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Neurotransmitters

• Neurotransmitters work to transmit electrical
  neuro-impulses across a synapse.
• Many stimulants enhance the neuro-impulse
  transmission systems.

L dopamine
Serotonin
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Stimulants

• The structures of many stimulants mimic
  chemical structures and are closely related to
  the neurotransmitters found in the body.

L Dopamine
Serotonin
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Amphetamines - Historical Development

• Amphetamines were initially developed as a
  cure-all for helping long haul truckers stay
  awake
• They were also used for weight control, to help
  athletes to perform better and train longer
• As amphetamine abuse became more common, it
  became evident that the dangers of abuse far
  outweighed therapeutic uses.

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Amphetamines

• Amphetamine was first marketed in the 1930s as
  Benzedrine, an over-the-counter inhaler to treat
  nasal congestion.
• It was also used in the treatment of the sleeping
  disorder, narcolepsy, and the behavioral syndrome
  called minimal brain dysfunction (MBD), which
  today is called attention deficit hyperactivity
  disorder (ADHD).
• During World War II, amphetamines were used to
  keep the fighting men going especially under
  intense battle conditions.

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Amphetamines

• Amphetamines closely mimic the chemical
  structure of adrenalin.

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Amphetamines

• Amphetamines act by
• constricting arteries, increasing perspiration
  activity and stimulating brain activity.
• increasing heart rate and blood pressure,
• increasing wakefulness, restlessness, agitation
  and insomnia.

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Amphetamines --Harmful Effects

• Highly addictive and toxic
• Long term use leads to deterioration of a number
  of body systems.
• Chronic abuse produces a psychosis that resembles
  schizophrenia and is characterized by paranoia,
  picking at the skin, preoccupation with one's own
  thoughts, and auditory and visual hallucinations.
  
• Severe depression and violent or erratic behavior
  are also common among meth addicts.

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Ecstasy

• Ecstasy is a powerful stimulant that has
  some characteristics in common with adrenalin and
  L-dopamine as well.

Repeated use of Ecstasy ultimately may damage the
cells that produce serotonin, which has an
important role in the regulation of mood,
appetite, pain, learning and memory.
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Ecstasy - Effects

• Because it mimics L-Dopamine, it has been
  used to relieve symptoms of Parkinsons Disease.
• Results in mental relaxation, increased
  sensitivity to stimuli and hallucinations.
• It can be produce fatal effects even from a
  single exposure

Attempts to synthesize new amphetamines led to so
called designer drugs, all of which are highly
dangerous.
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Nicotine

• Nicotine is an alkaloid found in the nightshade
  family of plants (Solanaceae)
• It constitutes approximately 0.63.0 of dry
  weight of tobacco

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Nicotine -Short Term

• Sympathomimetic
• Increases concentration and relieves tension
• Increased heart rate
• Increased blood pressure
• Reduction in urine output

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Nicotine Long Term

• Highly addictive
• Increased risk of heart disease and coronary
  thrombosis
• Increased stomach acid and risk of peptic ulcers
• Chronic lung disease
• Increased risk of cancer

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Nicotine -- Addiction and Withdrawal

• Highly addictive
• Cessation of smoking difficult
• Cravings
• Nausea, weight gain, insomnia, irritability, and
  depression

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Caffeine Characteristics

• Alkaloid
• Widely used stimulant found in coffee and tea.
• Added to some pain killers to speed up their
  effects.
• Not addictive in usual sense but mild withdrawal
  symptoms observed in some cases

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Caffeine Effects

• Increases alertness, concentration, and
  restlessness
• Diuretic
• Potential dependence

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Theobromine

• Found in chocolate
• Effects similar to caffeine.
• Structure is similar to that of caffeine but the
  methyl group on the nitrogen between the two
  carbonyl groups is missing

Theobromine
Caffeine
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Theobromine

• Although theobromine does not cause harmful
  effects with humans, it is highly toxic to some
  domestic animals, including dogs and horses.
• With the animals, theobromine can lead to cardiac
  arrhythmias and seizures.

Theobromine
Theobromine has a bitter flavor, which gives dark
chocolate its typical bitter taste.
Caffeine