Forensic Science: Fundamentals & Investigations, Chapter 9 1

Chapter 9 Drug Identification and Toxicology By the end of this chapter you will be able to:

o Identify the five types of controlled substances o Relate signs and symptoms of overdose with a

specific class of drugs or toxins o Describe the role of various types of toxins in

causing death o Discuss agents that may be used in bioterrorism o Define and describe the goals and practice of

toxicology All Rights Reserved South-Western / Cengage Learning © 2012, 2009

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Introduction

Forensic toxicology helps determine cause-and-effect relationshipsbetween

o Exposure to a drug or other substanceand

o Toxic or lethal effects from that exposure

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Introduction

People can be exposed to toxic substances: o intentionally—

by treating illness or relieving pain o accidentally—

by harmful combinations or overdoses o deliberately—

by harming or killing others, or by suicide

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Poison—Murder, Accidental Overdoses, and Drug Offences

o Poisoning causes less than ½ of 1% of all homicides

o Accidental drug overdoses are more commono Drug offenders

• More than 50% of the federal prison population• About 20% of the population in state prisons

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Controlled Substances

1. Hallucinogens2. Narcotics3. Stimulants4. Anabolic steroids5. Depressants

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Controlled Substances—Hallucinogens

o Often derived from plantso The effect and intensity of response to these

drugs varies from person to person. o Affects the user’s perceptions, thinking,

self-awareness, and emotions

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Controlled Substances—Hallucinogens

o Affects of an overdose often include • Increased heart rate • Increased blood pressure• Panic attacks, anxiety, or psychosis

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Controlled Substances—Hallucinogens

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Controlled Substances—Narcotics

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Controlled Substances—Stimulants

o Increases feelings of energy and alertness

o Suppresses appetiteo Afterwards, depression often resultso Overdose affects include high blood

pressure, agitation, confusion, seizureso Stimulants tend to be highly addictive

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Controlled Substances—Stimulants

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Controlled Substances—Anabolic Steroids

o A chemical structure similar to testosteroneo Promote cell and tissue growth increasing bone

mass and body muscle. o Popular with weightlifters, bodybuilders, and

other athleteso What are some of the negative side effects?

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Controlled Substances—Depressants

o Affects the central nervous system by increasing GABA activity, a neurotransmitter

o Increased GABA causes drowsiness and slowed brain activity

o Relieves anxiety and produces sleepo Side effects include slurred speech and loss of

coordinationo Mixing depressants with alcohol and other drugs

increases potency and health risks

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Controlled Substances—Alcohols

o In what way are alcohols toxic? o How is grain alcohol produced? o What are the classic symptoms of a

hangover? o What is the effect of alcohol on the central

nervous system? o What can chronic alcohol abuse cause?

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Controlled Substances—Bacterial Toxins

o Tetanus (also called Lockjaw)• Produced by the Clostridium tetani bacteria • Causes violent muscle spasms

o Botulism • Produced by Clostridium botulinum—botulism • Paralyzes muscles• Causes irreversible damage to nerve endings• Extremely deadly in very small amounts• Most poisonous biological substance

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Controlled Substances—Pesticides and Heavy Metals

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Controlled Substances—Pesticides and Heavy Metals

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Controlled Substances—Bioterrorism Agents

Ricin o A poisonous protein in the castor bean o Lethal in extremely small amountso Enters the body in various ways:

• inhaled as a mist or a powder • ingested as food or drink• injected into the body

o Causes death within a few hours

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Controlled Substances—Bioterrorism Agents

Anthrax o Bacillus anthracis, which forms endosporeso Spreads to humans from infected animals o Enters the human body through:

• Inhalation; causing breathing problems that usually result in death

• Ingestion; becoming fatal in 25% to 60% of cases • Absorption via the skin; leading to death in about

20% of untreated cases

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. . . . . . . . . Summary. . . . . . . .

o Forensic toxicology seeks to identify poisons or drugs in criminals and victims.

o Toxicology is important in studying cases of drug overdose and sporting violations.

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. . . . . . . . . . . . . Summary. . . .

o Controlled substances fall into five main groups:• Hallucinogens • Narcotic• Stimulants• Steroids• Depressants

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. . . . . . . . . . . . . . . . . Summary

o Poisons can be produced by living organisms. o Pesticides and heavy metals are common

poisons. o Bioterrorism agents include ricin and anthrax.