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You have a bad cold with a runny nose, cough and bad headache. You take three different medications for the symptoms.

Possible problem?

What toxic substances do you come in contact with in your everyday life?

How does the benefit of their use compare with the danger of exposure to their effects?

"All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy."

Paracelsus (1493­1541)

Examples of common substances that can be poisonous depending on the dose, length of exposure, or means of exposure.

Chapter 9 Drug Identification and Toxicology

• identify the five types of controlled substances • relate signs and symptoms of overdose with a specific class of drugs or toxins • describe the role of various types of toxins in causing death • discuss agents that may be used in bioterrorism • define and describe the goals and practice of toxicology

Introduction

• Toxicology is the study of poisons and the identification of drugs and other substances a person may have used for medicinal, recreational or criminal purposes.

­ Poison ­ a naturally occurring or manufactured substance that can cause severe harm or death if ingested, inhaled, or absorbed through the skin

­ Drug ­ a chemical substance that affects the processes of the mind or body

Introduction

Exposure to drugs or other toxins occurs by:• ingesting them so they enter gastrointestinal system• inhaling them into the lungs• injecting them into the bloodstream• absorbing them through the skin

Introduction Toxicity ­ the degree to which a substance is poisonous or can cause injury; depends on:• dose• duration ­ frequency and length of time• nature of exposure ­ ingested vs inhaled, etc• other factors such as drug interactions

Some substances are indirectly toxic because our body metabolizes them into harmful substances

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Introduction

• Exposure is determined by analyzing (1) body fluids, (2) stomach contents, (3) skin, (4) hair, (5) or in lethal cases, internal organs and vitreous humor of the eye.

• In addition to drugs, other toxic agents include heavy metals, solvents and vapors, radiation and radioactive materials, dioxins/furans, pesticides, and plant and animal toxins

http://www.ejnet.org/dioxin/

http://www.ejnet.org/dioxin/

Introduction

Forensic toxicology helps determine (a) the cause­and­effect relationships between exposure to a drug or other substance and (b) the toxic or lethal effects from that exposure.

People can be exposed to toxic substances: • intentionally—by treating illness or relieving pain • accidentally—by harmful combinations or overdoses • deliberately—by harming or killing others or by suicide

Poison—Murder, Accidental Overdoses, and Drug Offenses

• Less than ½ of 1% of all homicides. • Most commonly used today are arsenic, cyanide and strychnine, or industrial chemicals designed for other uses (fertilizers, etc)• Accidental drug overdoses are more common. • Acute poisoning ­ caused by a high dose over a short period of time• Chronic poisoning ­ caused by lower doses over long periods of time, which produces gradual symptoms (mercury, lead)

Poison—Murder, Accidental Overdoses, and Drug Offenses

Controlled substance ­ drug or other chemical compound whose manufacture, distribution, possession, and use is regulated by the legal system due to the effects and potential for abuse.

­ some narcotics, depressants, stimulants• Many illegal drugs, such as heroin and LSD have no currently accepted medical use• More than 50% of the federal prison population and about 20% of the population in state prisons consist of drug offenders.

Controlled Substances

Five classes:1) Hallucinogens2) Narcotics3) Stimulants4) Anabolic steroids5) Depressants

Controlled Substances—Hallucinogens

• The effect and intensity of response to these drugs varies from person to person. • Often derived from plants, hallucinogens affect the user’s perceptions, thinking, self­awareness, and emotions. • Affects of an overdose include an increased heart rate, increased blood pressure, and sometimes panic attacks, seizures, anxiety, or psychosis. • Danger is not always due to the drug, but to the person's actions while under its influence

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Controlled Substances—Narcotics

Narcotics reduce pain by suppressing the central nervous system and can be very habit forming.

Controlled Substances—Stimulants

• Stimulants increase feelings of energy and alertness while suppressing appetite. • As drug wears off, depression often results. • Sometimes abused to boost endurance/productivity• Affects of an overdose can include high blood pressure, rapid heart rate, irregular heart beat, dangerous rise in body temp, agitation, confusion, seizures, death. • Stimulants tend to be highly addictive. • Amphetamines, methamphetamines (more potent), cocaine

Controlled Substances—Anabolic Steroids

• Produced in a lab & have chemical structure similar to testosterone. • Used to treat delayed puberty, impotence, severe muscle wasting caused by HIV, etc.• Promote cell and tissue growth and division, increasing bone mass and body muscle. • Popular with weightlifters, bodybuilders, etc. • Negative side effects­acne, increased body hair, baldness, high blood pressure/cholesterol, impaired male fertility, blood clotting, kidney/liver cancer, heart attacks

Controlled Substances—Depressants

• Depressants act on the central nervous system and increase activity of a neurotransmitter called GABA. • Increased GABA production results in drowsiness, slowed brain activity, reduced body functions. • Used to relieve anxiety and produce sleep. • Side effects­slurred speech, loss of coordination• Overdose slows heart rate and breathing, possibly leading to coma and death. • Mixing depressants with alcohol and other drugs increases their effects and health risks

Aspirin Coumadin NexiumActifed Coricidin PrednisoneAllegra Cyclosporine PenicillinAleve Dimetapp RitalinAmpicillin Erthromycin RobitussinAmoxicillin Heparin ValiumAZT Imitrex ViagraCelebrex Lipitor XanaxCortisone Lotrel Zyrtec

Alcohols

1. In what way are alcohols toxic? 2. How is grain alcohol produced? 3. What are the classic symptoms of a hangover? 4. What can chronic abuse of alcohol cause? 5. What is the effect of alcohol on the central nervous system?

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http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001771

Bacterial Toxins ­ Botulism

• Botulism is the most poisonous biological substance• Produced by bacteria Clostridium botulinum, it is a neurotoxin, paralyzes muscles by blocking acetylcholine.• Irreversible damage to nerve endings means muscle strength may take months to return based on if/how quickly nerves sprout new endings. • Very small amounts are extremely deadly, painful muscle spasms before death. • botulism can be in canned vegetables, cured pork/ham, smoked or raw fish, honey or corn syrup, or spores that are in the air

Bacterial Toxins ­ Tetanus

• Potentially deadly nervous system disease • "Lockjaw", as it is sometimes called, is produced by the Clostridium tetani bacteria. • Its poison blocks nerve signals from the spinal cord to the muscles, causing violent muscle spasms.• Spasms can tear muscles and break bones• Often begins in jaw and can interfere with breathing• causes about 1 million deaths per year, only 5 per year in US, primarily in people who have not been vaccinated.

Pesticides and Heavy Metals

• Pesticides­used to protect plants or food crops. • Toxic to humans as well as the insects, etc that they are designed to kill.

• Metal compounds are very poisonous and have historically been used in suicides and homicides. • stored in soft tissues and build up over time to damage organs

Pesticides and Heavy Metals

Pesticides mostly are used to protect plants or food crops. Metal compounds are very poisonous.

Controlled Substances—Pesticides and Heavy Metals

Metal compounds can damage many organs in the body.

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Other Lethal Agents

• Hydrogen cyanide, used in gas chambers• Carbon monoxide from car exhaust, etc• potassium chloride or sodium pentothal, used in lethal injections• Produce death by inhibiting enzyme activity, interfering with ATP production, or stopping the heart by preventing electrical impulses.

Bioterrorism Agents

Ricin • is a poisonous protein in the castor bean. • is lethal in extremely small amounts, 500 micrograms­the size of the head of a pin. • can enter the body in various ways:inhaled as a mist or a powder, ingested as food or drink, injected into the body. • can cause death within a few hours by preventing cells from making necessary proteins.

Bioterrorism Agents Anthrax • is caused by bacteria Bacillus anthracis, which forms microscopic endospores ­ a thick­walled inactive cell that can later grow under favorable conditions.• can be spread to humans from infected animals.

Can enter the human body through: • inhalation­causing breathing problems that usually result in death. • ingestion­vomiting, etc., fatal in 25% to 60% of cases. • skin absorption­ leading to death in about 20% of untreated cases, death is rare with treatment