Toxicology Chapter 9 Toxicology Toxicology study of poisons

Toxicology Chapter 9

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.

(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.

Method of Administration/Exposure 1) Ingestion – substance is eaten and transferred to bloodstream through lining of mouth, stomach, & small intestine.

Method of Administration/Exposure 2) Inhalation – substance is inhaled into lungs and absorbed into bloodstream during respiration.

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).

Method of Administration/Exposure 4) Absorption: substance is absorbed through the skin and into the bloodstream.

Toxicity • Toxicity: the degree to which a substance is poisonous or can cause injury. • Depends on these factors: 1. 2. 3. 4. 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)

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 • •

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.

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

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 19 th century, it had acquired the nickname "inheritance powder, " perhaps because impatient heirs were suspected to use it to accelerate their inheritances.

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

Read Article: Who Killed Alexander Litvinenko? 1. 2. 3. 4. Who was Alexander Litvinenko? Why was he poisoned? What was he poisoned with? What symptoms did he experience? 5. What was the mechanism of death? 6. Why did it take so long for doctors to determine what he was poisoned with?

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 – These drinks were banned in Nov. 2010.

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

Federal Law Potential for Abuse Used in Medicine? Examples Schedule 1 Illegal Drugs High No Heroin, LSD, MDMA (ecstasy), marijuana Schedule 2 High Yes – but restricted Opium, Morphine, Codeine, Oxycodone, Cocaine, Amphetamine, Methamphetamine Schedule 3 Moderate Yes Anabolic steroids, Ketamine, Phenobarbital, Tylenol plus codeine Schedule 4 Low Yes Diazepam (Valium) Schedule 5 Low Yes Low-grade stimulants, low-dose narcotics, cough suppressants

Drugs and Crime • Arrests for drug abuse have been rising steadily since the early 1990 s. – Drug offenders account for more than half of federal prisons inmates & 20% of state prison inmates.

Controlled Substances • Five Classes of Controlled Substances: 1) Stimulants 2) Hallucinogens 3) Narcotics 4) Anabolic steroids 5) Depressants

Jigsaw Activity • Read the article, outline specifics with regards to each controlled substance. • Share with group. • You are responsible for understanding the information on each of the 5 classes.

Other Organic Toxins • Organic toxins – toxins produced by living organisms that will interfere with another organism’s metabolism • Examples: 1) Venom – bee sting, snake bite 2) 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.

Other Organic Toxins 3) Bacterial Toxins – Botulism 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

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

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.