Download Chemicals and the Body

Communication and
Structure
•Chemicals and the Body
Chemicals and the Body
• Agonists-Drugs that mimic a neurotransmitter.
• Antagonists-Drugs that stop a neurotransmitter.
Chemicals and the Body
Psychoactive Drug: A drug capable of influencing perception, mood, cognition, or
behavior.
Methods of getting a drug into the body:
Via Inhalation
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Nasal Cavity
Lungs
Smoked
Via Injection
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Subcutaneous
Intraparatineal
Intravenous
Intramuscular
Via Absorption
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Skin
Mouth
Anal Cavity (intestines)
Via Ingestion
Fat/Water Soluble Distinction
Fat Soluble:
• Stored– Bodies fat tissues
– Fat deposits
– Liver
• Storage methods make these substances potentially
poisons.
– Potential to build up to harmful levels in the body
– Active in the brain because they bind to fats.
Water Soluble:
• Not easily stored.
• Used the moment they enter the body.
• Unused material is flushed out.
Major Categories
Stimulants:
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Speed up activity in the CNS.
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Nicotine, Caffeine, Cocaine, Amphetamines
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Ritalin and Adderall
Depressants:
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Slow down activity in the CNS.
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Alcohol, Tranquilizers, Barbiturates
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Most Inhalants
Opiates:
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Relieve pain.
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Opium, Morphine, Heroin
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Methadone
Psychedelic drugs:
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Disrupt normal thought processes.
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Lysergic Acid Diethylamide (LSD),
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Mescaline (Peyote Cactus Buttons)
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Salvia Divinorum, Psilocybin (Mexican Magic Mushrooms),
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Marijuana (Tetra-Hydra-Cannibinol)
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Nutmeg, Thyme, Mace
Chemicals and the Body
Naloxone– Counters Heroin.
– Also counters the placebo effect.
Symptomatology
•
Tolerance: Increased resistance to a drug’s effects
accompanying continued use.
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Withdrawal Symptoms: Physical and psychological symptoms
that occur when someone addicted to a drug stops taking it.
– Withdrawal from a depressant can kill you
– Withdrawal from an opiate will make you wish you were dead
Therapeutic Window
Defined: (Therapeutic Index) Comparison of the
amount of a therapeutic agent that causes the
therapeutic effect to the amount that causes
toxic effects.
– Quantitatively, it is the ratio given by the dose required
to produce the toxic effect divided by the therapeutic
dose
– Commonly used measure of therapeutic index is the
lethal dose of a drug for 50% of the population divided
by the effective dose for 50% of the population
TR = LD50 / ED50