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? "All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy." Paracelsus (1493 1541) Examples of common substances that can be poisonous depending on the dose, length of exposure, or means of exposure. How does the benefit of their use compare with the danger of exposure to their effects? 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 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 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 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 1
http://www.ejnet.org/dioxin/ 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/ Forensic toxicology helps determine (a) the cause and effect 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) Hallucinogens 2) Narcotics 3) Stimulants 4) Anabolic steroids 5) Depressants 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, self awareness, 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 2
Narcotics Narcotics reduce pain by suppressing the central nervous system and can be very habit forming. 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 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 effects acne, increased body hair, baldness, high blood pressure/cholesterol, impaired male fertility, blood clotting, kidney/liver cancer, heart attacks 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 effects slurred 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 Nexium Actifed Coricidin Prednisone Allegra Cyclosporine Penicillin Aleve Dimetapp Ritalin Ampicillin Erthromycin Robitussin Amoxicillin Heparin Valium AZT Imitrex Viagra Celebrex Lipitor Xanax Cortisone 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? 3
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 Pesticides and Heavy Metals 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 used 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. Pesticides and Heavy Metals Metal compounds can damage many organs in the body. 4
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 thick walled inactive cell that can later grow under favorable conditions. can be spread to humans from infected animals. Can enter the human body through: inhalation causing breathing problems that usually result in death. ingestion vomiting, etc., fatal in 25% to 60% of cases. skin absorption leading to death in about 20% of untreated cases, death is rare with treatment 5