# 11 - toxicology and drugs

Drugs and Their Effects

• Definition of Drugs:

  • A drug is a chemical substance causing changes in physiology or psychology when consumed.

  • Distinct from food as it does not primarily provide nutritional support.

  • Methods of consumption include inhalation, injection, smoking, ingestion, absorption (skin patches), suppository, or dissolution under the tongue.

• Pharmacology:

  • Involves studying drugs that produce biological effects when administered.

Types of Drug Dependence

• Defining Drugs:

  • Drugs can be natural or synthetic substances producing physiological or psychological effects in organisms.

  • Two main aspects of drug experience:

    • Psychological Dependence: Involves the mental and emotional relationship to the drug.

    • Physical Dependence: A physiological need for the drug due to regular use, leading to withdrawal symptoms.

• Factors Influencing Dependence:

  • The nature of the drug, route of administration, dosage, frequency of use, and individual metabolism play critical roles.

  • User characteristics, expectations about effects, societal attitudes, and usage settings are major determinants.

• Common Drugs:

  • Marijuana and cocaine are examples of drugs usually not causing physical dependence.

Psychological and Physical Dependence

• Psychological Factors:

  • Personal characteristics, societal influences, expectations, and settings greatly influence psychological dependence.

  • Some drugs like alcohol, heroin, or cocaine lead to significant psychological involvement, while others like marijuana possess lower abuse potential.

• Physical Dependence:

  • Represents a body's physiological need for a substance to avoid withdrawal or abstinence syndromes.

Forensic Toxicology

• Definition:

  • A branch of science applying toxicology to legal investigations involving drug effects on humans.

• Analytical Chemistry in Toxicology:

  • Involves techniques to identify and quantify substances related to toxic effects for judicial purposes.

Differences between Forensic Chemists and Toxicologists

• Forensic Toxicology:

  • Focus on evaluating the effects of toxins or poisons in crime-related contexts.

  • Examines substances affecting biological fluids for legal cases.

• Forensic Chemistry:

  • Studies chemical properties and interactions within a laboratory or crime scene setting.

  • Works with a broader scope of materials not exclusively related to human physiology.

Methods and Techniques

• Toxicology Techniques:

  • Includes methods like UV spectroscopy, gas and liquid chromatography, mass spectrometry, and immunoassays.

• Chemistry Techniques:

  • Utilizes traditional analytical chemistry methods to identify unknown components in samples.

Types of Drugs

• By Origin and Function:

  • Natural: Naturally occurring substances (e.g., alkaloids).

  • Semi-synthetic: Modified natural substances (e.g., heroin, derived from morphine).

  • Synthetic: Entirely man-made substances.

Common Drug Classifications**:

• Analgesics: Pain relief (e.g., aspirin, morphine).

• Narcotics: Central nervous system depressants causing an analgesic effect (e.g., opium-derived drugs).

• Depressants: Drugs that reduce CNS activity (e.g., alcohol, barbiturates).

• Stimulants: Increase alertness and activity (e.g., cocaine, amphetamines).

• Hallucinogens: Alter perceptions and mood (e.g., LSD, marijuana).

Cocaine and Stimulants

• Cocaine: Origin and extraction process.

  • Cocaine HCI is derived through a detailed chemical process which yields different forms of cocaine.

• Properties of Cocaine:

  • Freebase and crack cocaine vary in solubility and functioning.

Analgesics and Their Properties

• Aspirin vs. Morphine:

  • Aspirin is anti-inflammatory; morphine is an effective painkiller with euphoric effects.

  • Aspirin reduces inflammation; morphine blocks pain signals.

Depressant Overview

• Alcohol and Benzodiazepines:

  • Both types induce relaxation but operate through different mechanisms in the brain.

Additional Drug Classifications

• Narcotics:

  • Derived from natural opiates; lead to significant addiction potential.

• Stimulants: Differentiate between natural and synthetic origins.

• Hallucinogens: Examine effects based on different ingestion methods.

Legal Classification of Drugs Under the Controlled Substances Act

• Schedules of Drugs:

  • Schedule I: No medical use - high abuse potential.

  • Schedule II: High abuse potential with severe medical restrictions.

  • Schedule III: Moderate abuse potential with accepted medical uses.

  • Schedule IV: Low abuse potential and currently accepted medical uses.

  • Schedule V: Lowest abuse potential with accepted medicinal uses.

Important Notes about Marijuana (THC)

• Cannabis Variants:

  • Different parts of the plant possess varying THC levels, with resin being the richest source.

  • Marijuana exhibits psychoactive properties with lower physical dependency risks, although heavy use can cause other health issues.