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Toxicology Chapter 9
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Toxicology Toxicology: study of poisons and drugs and their effect on the body. Poison: a naturally-occurring or manufactured substance that can cause severe harm or death. Toxin: a poisonous substance naturally produced by certain plants, animals, and bacteria that is capable of causing disease or death in humans.
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(cont’d) Drug: 1) Any chemical substance that affects the processes of the mind or body. 2) A substance used in the diagnosis, treatment, or prevention of a disease. 3) A substance used recreationally Ex. narcotic, hallucinogen.
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Method of Administration/Exposure
Ingestion – substance is eaten and transferred to bloodstream through lining of mouth, stomach, & small intestine.
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Method of Administration/Exposure
2) Inhalation – substance is inhaled into lungs and absorbed into bloodstream during respiration.
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Method of Administration/Exposure
3) Injection – substance is injected through the skin (transdermal injection) into muscle tissue (intramuscular) or directly into a blood vessel (intravenous).
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Method of Administration/Exposure
4) Absorption: substance is absorbed through the skin and into the bloodstream.
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Toxicity Toxicity: the degree to which a substance is poisonous or can cause injury. Depends on these factors: Dose (how much was taken) Duration (frequency & length of exposure) Method of exposure (ingested, inhaled, injected, absorbed) Interactions with other substances in body (ex. alcohol or prescription drugs)
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How do you Test for the Presence of Poisons & Drugs?
Body fluids (ex. urine) Stomach contents Internal Organs (ex. liver) Vitreous humor fluid of the eye Breathalyzer Hair Skin
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When someone is poisoned, investigators classify that exposure as...
Intentional – Drugs taken to treat an illness or relieve pain. Accidental – Unintentional overdoses or harmful combinations. Ex. legal prescriptions (ex. pain killers) & alcohol (2:07) Ex. heroin and alcohol (My 23-year-old cousin died of this!!!) Deliberate – An exposure intended to kill/harm someone; suicide.
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History of Poisoning Greek Philosopher Socrates was one of the earliest victims of poisoning. Found guilty of “refusing to recognize the gods” and “corrupting the youth”, he was sentenced to death by hemlock poisoning in 399 B.C
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History of Poisoning Rich families & royalty of Europe used arsenic & cyanide to settle disputes. Arsenic became a favorite murder weapon of the Middle ages and Renaissance, particularly among ruling classes in Italy. Because the symptoms are similar to those of cholera, which was common at the time, arsenic poisoning often went undetected. By the 19th century, it had acquired the nickname "inheritance powder," perhaps because impatient heirs were suspected to use it to accelerate their inheritances.
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Poisoning Very common in literature, but not a very common form of murder. Less than 0.5% of homicides result from poisoning. Common poisons today include: arsenic, cyanide, strychnine, and chemicals normally used as fertilizers and antifreeze. Acute Poisoning: high dose over short time Ex. cyanide poisoning causes symptoms immediately Chronic Poisoning: low doses over longer time Ex. mercury and lead accumulate slowly in body and produce symptoms gradually
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Read Article: Who Killed Alexander Litvinenko?
Who was Alexander Litvinenko? Why was he poisoned? What was he poisoned with? What symptoms did he experience? What was the mechanism of death? Why did it take so long for doctors to determine what he was poisoned with? Answers: Former agent in Russia’s KGB Spoke out against the Kremlin Radioactive polonium Vomiting, hair loss, collapsing of internal organs, decline in white blood cells Internal organs collapsing Polonium is very rare and very expensive, bizarre & expensive way to kill someone
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Accidental Drug Overdoses
More common than deaths from deliberate poisoning. Ex. Whitney Houston, John Belushi, Heath Ledger, Chris Farley, River Phoenix, Steve Clark, Janis Joplin, Jim Morrison, Jimi Hendrix. In the News: FDA to ban caffeinated alcohol drinks Update: These drinks were banned in Nov
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Drugs and Crime Illegal Drugs: drugs with no current medical use (Schedule 1). Ex. heroin, LSD Controlled Substances: legal drugs whose sale, possession, and use are restricted because of the effect of the drugs and the potential for abuse. Ex. narcotics, depressants, stimulants
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Federal Law Potential for Abuse Used in Medicine? Examples Schedule 1 Illegal Drugs High No Heroin, LSD, MDMA (ecstasy), marijuana Schedule 2 Yes – but restricted Opium, Morphine, Codeine, Oxycodone, Cocaine, Amphetamine, Methamphetamine Schedule 3 Moderate Yes Anabolic steroids, Ketamine, Phenobarbital, Tylenol plus codeine Schedule 4 Low Diazepam (Valium) Schedule 5 Low-grade stimulants, low-dose narcotics, cough suppressants
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Drugs and Crime Arrests for drug abuse have been rising steadily since the early 1990s. Drug offenders account for more than half of federal prisons inmates & 20% of state prison inmates.
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Activity: Marijuana Debate
Background: Marijuana is classified as a Schedule 1 drug under the Controlled Substances Act. Accordingly it is currently legislated as having “no accepted medical use in treatment in the United States.” At the federal level, marijuana can be used for research purposes only and it is otherwise illegal to possess. However it is commonly argued that marijuana can be effectively used to manage a host of medical problems. The past few decades have seen a number of initiatives that have resulted in legalization for medical use at the state level. The resulting tension between federal and state authority has led to a number of high profile confrontations between the Drug Enforcement Administration (DEA) and hospices openly dispensing marijuana in cooperation with state and local agencies. Should the use of marijuana be legalized for medical purposes, yes or no? In order to make an educated decision, you will read some personal stories and read some background information on the topic. Then you will enter into a debate and come to a conclusion.
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Activity: Marijuana Debate
Everyone – Read both stories. Come up with pro/con list based on stories and your own prior knowledge. Each partner should read a different list. Partner 1 – Read list of Pros. Partner 2 – Read list of Cons. Discuss and debate with your partner. Agree on whether or not to legalize marijuana. If you decide to legalize it, would it be just for medical purposes or for all purposes? Write an argument paragraph using facts to justify your position. Discuss as a class.
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Controlled Substances
Five Classes of Controlled Substances: Stimulants Hallucinogens Narcotics Anabolic steroids Depressants
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1) Hallucinogens Often derived from plants
Affect perception, thinking, self-awareness, emotions Examples: Mescaline from a peyote cactus Marijuana Extract from mushrooms
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1) Hallucinogens (cont’d)
LSD Found on a fungus that grows on rye and other grains Odorless, colorless, tasteless Very potent mood-changer MDMA (the amphetamine ecstasy) PCP (angel dust) First developed as an anesthetic, but produced hallucinations Can cause people to lose touch with reality for weeks In powder, tablet, or capsule form
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2) Narcotics Reduce pain by suppressing central nervous system’s (CNS) ability to relay pain messages to the brain Alters mood/behavior Causes drowsiness and sleep. Very addictive Street drugs: Opium Heroin (derived from opium) Prescribed drugs (derived from opium): Morphine Hydrocodone (Vicodin, Lortab) Oxycodone (Percocet, OxyContin) Codeine (Tylenol 3)
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3) Stimulants Increased energy, alertness, productivity, endurance.
Suppresses appetite. Depression results when drug wears off. Highly addictive. Examples: Amphetamines (Speed) Methamphetamines (more potent than amphetamines) Cocaine/crack
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4) Anabolic Steroids Promote cell and tissue growth and division.
Produced in the lab. Have structure similar to testosterone. Originally used to treat hypogonadism (low production of testosterone) Now used to treat: delayed puberty, impotence, muscle wasting (deterioration) caused by HIV. Used (abused) by weightlifters to increase muscle and bone mass. Negative side effects: acne, increased body hair, baldness, high blood pressure & cholesterol, impaired fertility in men, blood clotting, kidney & liver cancers, heart attacks.
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5) Depressants Relieve anxiety & produce sleep
Reduce body functions (ex. heart rate) by acting on the CNS and increasing the neurotransmitter, GABA. This produces drowsiness and slows brain activity. Side effects: slurred speech, loss of coordination, similar to alcohol intoxication Overdose can lead to slowed breathing and heart rate, coma and death. Mixing depressants with alcohol increases their effect. Examples: Barbiturates Benzodiazepines
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Activity: Drugs of Abuse
Instructions Fill in the table. Be sure to include origin (where appropriate), effects, and specific types (where appropriate). Your Goal: Given a description of one of these substances, you should be able to choose which one is being described. Make sure you include distinguishing characteristics.
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Activity: “I Can Quit Anytime I Want”
Cocaine Addiction
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Other Organic Toxins Organic toxins – toxins produced by living organisms that will interfere with another organism’s metabolism Examples: Venom – bee sting, snake bite Alcohols Methanol – not directly poisonous, but is converted by liver into formaldehyde which is very toxic Ethanol – produced by fermentation of sugar in fruits, grains, and vegetables The body converts ethanol into acetaldehyde which causes dehydration when it accumulates in the blood (causing hangover symptoms) Chronic abuse causes liver damage, dangerous behavior, depression of CNS, and permanent memory loss.
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Other Organic Toxins 3) Bacterial Toxins Botulism Tetanus
Produced by Clostridium botulinum Found in contaminated food Most poisonous biological toxin known to man Paralyzes muscles by blocking the neurotransmitter acetylocholine Botox is just purified botulinum toxin! Used to treat muscle spasms, eye conditions, excessive sweating headaches, stimulate wound healing, and as a cosmetic treatment Tetanus Produced by Clostridium tetani Causes deadly nervous system disease Causes muscles to spasm (starts as “lockjaw”), interferes with breathing
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Other Organic Toxins 4) Pesticides & Heavy Metals
Pesticides – ex. DDT, aldrin, dieldrin Carcinogens, thinning of bird eggs. Metals – lead, arsenic, mercury (Mad Hatter’s Disease) Other lethal agents interfere with production of ATP or destroying cell’s ability to transmit electrical impulses: Hydrogen cyanide - gas chambers Carbon monoxide - car exhaust Potassium chloride or sodium pentothal - lethal injection
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Other Organic Toxins 5) Bioterrorism Agents Ricin
Waste product of the manufacture of castor oil from castor beans. Prevents cells from making proteins. Anthrax – inhalation of endospores Produced by Bacillus anthracis 2001 – 22 cases of anthrax infection from envelopes sent through U.S. postal service, 11 deaths.
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Case Study – Georgi Markov
List all the steps that were taken to determine what had killed Georgi Markov.
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After your Test Read Case Study: Eva Rablen
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