Toxicology Forensic Toxicology the use of toxicology and

Toxicology • Forensic Toxicology – the use of toxicology and other disciplines such as analytical chemistry, pharmacology, and clinical chemistry to aid medical or legal investigation of death, poisoning, and drug use. – Toxicology – the branch of science concerned with the nature, effects, and detection of poisons FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -1

Toxicology • Toxin – An antigenic poison or venom of plant or animal origin, especially one produced by or derived from microorganisms and causing disease when present at low concentration in the body. – Examples: recreational drugs, alcohol, poison FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -2

Types of Drugs • A drug can be defined as a natural or synthetic substance that is used to produce physiological or psychological effects in humans or other higher order animals. • Narcotic drugs are analgesics, meaning they relieve pain by a depressing action on the central nervous system. This effects functions such as blood pressure, pulse rate and breathing rate. • The regular use of a narcotic drug will invariably lead to physical dependence. • The most common source for these narcotic drugs is opium, extracted from poppies. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -3

Opiates • Morphine is readily extracted from opium and is used to synthesize heroin. • Addicts frequently dissolve heroin in water by heating it in a spoon, and then inject in the skin. • Heroin produces a “high” that is accompanied by drowsiness and a sense of well-being that generally last for three to four hours. • Codeine is also present in opium, but it is usually prepared synthetically from morphine. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -4

Other Opiates • Oxy. Contin, with the active ingredient oxycodone, is not derived from opium or morphine, but does have the same physiological effects on the body as do opium narcotics. • Oxy. Contin is prescribed to a million patients for treatment of chronic pain. • Methadone is another well-known synthetic opiate. • Methadone, which is pharmacologically related to heroin, appears to eliminate the addict’s desire for heroin while producing minimal side effects. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -5

Hallucinogens • Another class of drugs is hallucinogens; marijuana is the most well-known member of this class. • Hallucinogens cause marked changes in normal thought processes, perceptions, and moods. • Marijuana is the most controversial drug in this class because its long-term effects on health are still largely unknown. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -6

Marijuana • Marijuana refers to a preparation derived from the plant Cannabis. • The chemical substance largely responsible for the hallucinogenic properties of marijuana is known as tetrahydrocannabinol, or THC. • The THC content of Cannabis varies in different parts of the plant, generally decreasing in the following sequence: resin, flowers, leaves, with little THC in the stem, roots or seeds. • The THC-rich resin is known as hashish. • Marijuana does not cause physical dependency, but the risk of harm is in heavy, long-term use. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -7

Other Hallucinogens • Other hallucinogens include LSD, mescaline, PCP, psilocybin, and MDMA (Ecstasy). • LSD is synthesized from lysergic acid, and can cause hallucinations that can last for 12 hours. • Phencyclidine, or PCP, is often synthesized in clandestine laboratories and is often smoked, ingested, sniffed. • Phencyclidine is often mixed with other drugs, such as LSD, or amphetamine, and is sold as a powder (“angel dust”), capsule, or tablet. • Oral intake of PCP first leads to feelings of strength and invulnerability, which may turn to depression, tendencies toward violence, and suicide. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -8

Stimulants • The drug classification of stimulants includes amphetamines, sometimes known as “uppers” or “speed, ” and cocaine, which in its free-base form is known as crack. • Stimulants are substances taken to increase alertness or activity, followed by a decrease in fatigue and a loss of appetite. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -9

Stimulants • Amphetamine and methamphetamine, often injected intravenously, cause an initial “rush, ” followed by an intense feeling of pleasure. • This is followed by a period of exhaustion and a prolonged period of depression. • Cocaine, extracted from the leaves of Erythroxylin coca, causes increased alertness and vigor, accompanied by the suppression of hunger, fatigue, and boredom. • Crack is cocaine mixed with baking soda and water, then heated. • Crack is often smoked in glass pipes, and like cocaine stimulates the brain’s pleasure center. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -10

Club Drugs • The term club drugs refers to synthetic drugs that are used at nightclubs, bars, and raves (allnight dance parties). • Substances that are often used as club drugs include, but are not limited to, MDMA (Ecstasy), GHB (gamma hydroxybutyrate), Rohypnol (“Roofies”), ketamine, and methamphetamine. • GHB and Rohypnol are central nervous system depressants that are often connected with drugfacilitated sexual assault, rape, and robbery. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -11

Club Drugs • MDMA or Ecstasy, is a synthetic mind-altering drug that exhibits many hallucinogenic and amphetaminelike effects. • Ecstasy enhances self-awareness and decreases inhibitions, however, seizures, muscle breakdown, stroke, kidney failure, and cardiovascular system failure often accompany chronic abuse. • Ketamine is primarily used as a veterinary animal anesthetic that in humans causes euphoria and hallucinations. • Ketamine can also cause impaired motor functions, high blood pressure, amnesia, and mild respiratory depression. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -12

Anabolic Steroids • Yet another category of drugs is the anabolic steroids. • These are synthetic compounds that are chemically related to the male sex hormone testosterone. • Anabolic steroids are often abused by individuals who are interested in accelerating muscle growth. • Side effects include unpredictable effects on mood and personality, depression, diminished sex drive, halting bone growth, and liver cancer. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -13

Depressants • Depressants are another class of drugs. • Depressants are substances used to depress the functions of the central nervous system. • Depressants calm irritability and anxiety and may induce sleep. • These include alcohol (ethanol), barbiturates, tranquilizers, and various substances that can be sniffed, such as airplane glue, model cement, or aerosol gas propellants such as freon. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -14

Depressants • Alcohol (ethyl alcohol) enters the body’s bloodstream and quickly travels to the brain, where it acts to suppress the brain’s control of thought processes and muscle coordination. • Barbiturates, or “downers, ” are normally taken orally and create a feeling of well-being, relax the body, and produce sleep. • Tranquilizers, unlike barbiturates, produce a relaxing tranquility without impairment of highthinking faculties or inducing sleep. • Sniffing has immediate effects such as exhilaration, but impairs judgment and may cause liver, heart, and brain damage, or even death. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -15

Toxicology of Alcohol • The analysis of alcohol exemplifies the primary objective of forensic toxicology—the detection and isolation of drugs in the body for the purpose of determining their influence on human behavior. • Alcohol, or ethyl alcohol, is a colorless liquid normally diluted with water and consumed as a beverage. • Like any depressant, alcohol principally effects the central nervous system, particularly the brain. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -16

Alcohol Levels • Alcohol appears in the blood within minutes after it has been taken by mouth and slowly increases in concentration while it is being absorbed from the stomach and the small intestine into the bloodstream. • When all the alcohol has been absorbed, a maximum alcohol level is reached in the blood; and the postabsorption period begins. • Then the alcohol concentration slowly decreases until a zero level is again reached. • Factors such as time taken to consume the drink, the alcohol content, the amount consumed, and food present in the stomach determine the rate at which alcohol is absorbed. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -17

Alcohol Levels • Elimination of alcohol throughout the body is accomplished through oxidation and excretion. • Oxidation takes place almost entirely in the liver, while alcohol is excreted unchanged in the breath, urine, and perspiration. • The extent to which an individual may be under the influence of alcohol is usually determined by either measuring the quantity of alcohol present in the blood system or by measuring the alcohol content in the breath. • Experimental evidence has verified that the amount of alcohol exhaled in the breath is in direct proportion to the blood concentration. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -18

Alcohol & Circulatory System • Humans have a closed circulatory system consisting of a heart, arteries, veins, and capillaries. • Alcohol is absorbed from the stomach and small intestines into the blood stream. • Alcohol is carried to the liver where the process of its destruction starts. • Blood, carrying alcohol, moves to the heart and is pumped to the lungs. • In the lungs, carbon dioxide and alcohol leave the blood and oxygen enters the blood in the air sacs known as alveoli. • Then the carbon dioxide and alcohol are exhaled during breathing. FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -19

Mouse Party Activity • Synapse - a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter • Neurotransmitter - a chemical substance that is released at the end of a nerve fiber by the arrival of a nerve impulse and, by diffusing across the synapse or junction, causes the transfer of the impulse to another nerve fiber, a muscle fiber, or some other structure FORENSIC SCIENCE An Introduction By Richard Saferstein PRENTICE HALL © 2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 5 -20