Forensic Toxicology and Pharmacology

# Forensic Toxicology and Pharmacology ## Introduction Forensic Toxicologists analyze evidence to determine if toxins/drugs are present. ## Toxicology - The study of drugs, poisons, toxins and also include metabolites (by products formed when the body breaks down drugs/poisons). - **Poisons:**...

# Forensic Toxicology and Pharmacology ## Introduction Forensic Toxicologists analyze evidence to determine if toxins/drugs are present. ## Toxicology - The study of drugs, poisons, toxins and also include metabolites (by products formed when the body breaks down drugs/poisons). - **Poisons:** Natural/manufactured chemicals that can cause serious harm. The Marsh test was used to test for arsenic. - Examples: Arsenic, Rat Poison - **Toxins:** Naturally occurring poisonous substances produced by living things. - Toxicologists develop specific tests and technologies to determine harmful substances. - Body fluids: stomach contents, or fluids from inside the eye. - If the person is deceased, stomach contents and tissue samples from the liver and kidney will be examined. ## History of Forensic Toxicology - “All substances are poisons; there is none which is not a poison. The right dose differentiates a poison and a remedy!” - Paracelsus - Socrates was one of the earliest victims of poisoning, infamously. - In 1600, arsenic was used as a poison as it is extremely toxic in small amounts and mimics natural disease. - 1800s: Mathieu Orfila and Robert Christison popularized methods of chemical analysis to identify arsenic in tissues. - 1918: Charles Norris, the first medical examiner in New York, and Alexander Gettler, director of the first toxicology lab developed standardizing techniques and testing to determine the cause of death. ## Science of Toxicology **Exposure to toxins, poisons and drugs: ADME** 1. **Absorption** - Either through the digestive tract, lungs, bloodstream, or skin, the chemical is introduced to your body. 2. **Distribution** - Through the circulatory system. Chemicals are carried to the brain, liver, and kidneys, and the rest of the body. 3. **Metabolism** - Forms metabolites as the chemical is broken down. - If ingested, the chemical might be digested before absorbed. - Liver: If large quantities are absorbed, the liver can only process a limited amount, and the remaining toxin is circulated throughout the body. 4. **Excretion** - Kidney → Urine - Intestines → Faces - Skin → Sweat - Lungs → Breath ## How Toxins and Drugs Affect the Body - **Acetaminophen (Tylenol)**: Destroys cells and the liver’s ability to detoxify substances. - **Cyanide:** Binds to hemoglobin on RBC instead of oxygen, leading to a lack of oxygen, loss of consciousness, and death. - **Fentanyl:** 50x stronger than heroin, affects respiratory control, results in many overdoses and accidental deaths. - **Botulinum Toxin (Botox)**: Paralysis of muscles, affecting breathing and heart death. - **Cocaine:** High blood pressure, heart attack, stroke. - **5 Classes:** Stimulants, narcotics, depressants, hallucinogens, and anabolic steroids. ## Toxicity Factors - **Dosage:** Amount taken. - **Potency:** Drugs with high strength may be lethal in small amounts. - **Duration:** Frequency and length of exposure. - **Nature of the Exposure:** Injected, inhaled, ingested, absorbed through skin. - **Toxic Metabolites from Non-Toxic Substances:** Methanol’s metabolite formic acid can cause blindness and death in small quantities. ## Symptoms of Poisoning ### Indicators - Death with no signs of trauma. - Sudden unexpected death. - Unexplained illness that recurs in cycles. - Similar symptoms found in many people at the same time. - Unexplained loss of consciousness. ## Drug Addiction, Withdrawal, and Dependency. - **Addiction:** Feelings of pleasure produced by a drug when it mimics neurotransmitters, leading to have a physiological need for the drug. - **Withdrawal:** Reduced/discontinued use of an addictive drug results in physical/mental symptoms – illness or death. - **Drug Dependency:** Intense craving for the drug but unlike addiction, doesn’t result in withdrawal when discontinued. - **Drug Tolerance:** Tolerance is when a person needs to take more of the drug to feel the same sensation. ## Characteristics of Poisons, Toxins, Drugs ### Heavy Metals - Enter the body through ingestion, inhalation, absorption through skin, or mucous membranes. - Stored in soft tissues and damage organs. ### Arsenic - Contaminates drinking water. - Overexposure leads to gastrointestinal symptoms, difficulty speaking, muscle cramps, convulsions, kidney failure, and death. - Lesser chronic exposure → skin lesions, headache, personality changes. ### Mercury - Industrial wastes dumped into the body of water, coal-fired power plant pollutant. - Exposure leads to Mad Hatter’s disease and death. - **Acute poisoning:** Muscle aches and stomach upset. - **Chronic poisoning:** Irritability, memory and balance problems, abdominal pain, nausea etc. ### Lead - Naturally occurring element, older paints. - Blue discoloration appears along the gum line in the mouth. - Nausea, abdominal pain, insomnia, kidney problems, etc. ### Potassium Chloride - Affects the heart's ability to send electric signals. ### Sodium Pentothal - Acts as a depressant and slows down the CNS. ## Pesticides and Herbicides - Aldrin, Dieldrin (pesticides): Anxiety, seizures, rapid heartbeat, muscle weakness, etc. ### Glyphosate Mixture (Herbicide) - Gastrointestinal problems, skin and eye irritation, kidney malfunction, death. ## Biofluids - Blood, urine, bile, etc. ## Toxins - Toxins of interest are substances produced by plants, animals, fungi. ### Ex: Ricin - Waste product from the manufacture of castor oil from castor beans. - Lethal to humans in small quantities. - Can be inhaled as mist/powder, ingested or injected. ## Drugs and Drug Schedules - **Illicit Drugs:** Drugs with no current medical use. - **Controlled Substances:** Legal drugs whose sale, possession, and use are restricted. ## Controlled Substances Act → 5 Schedules - **Schedule I:** No medical use, high potential for abuse. - Examples: Heroin, LSD, MDMA. - **Schedule II:** Severely restricted medical use, highly potential for abuse. - Examples: Cocaine, fentanyl, methamphetamine, methadone, morphine, oxycodone. - **Schedule II:** Accepted medical use, moderate potential for abuse, moderate - low risk dependence. - Examples: Anabolic steroids, ketamine, Vicodin, Tylenol with codeine, testosterone. - **Schedule IV:** Medical use, low potential for abuse, low risk dependency. - Examples: Xanax, Valium, sleeping pills, other tranquilizers. - **Schedule V:** Widely used for medical purposes, very low potential for abuse, has limited quantities for narcotics. - Examples: Lyrica, cod. ## Illegal Drugs ### Hallucinogens (Schedule I) - Affect perception, thinking, self-awareness, emotions. - Physical reactions include increased heart rate and blood pressure and dilated pupils, visual effects in flashbacks. ## Narcotics - Affect levels of serotonin. - Derived from natural opium/synthetic, are highly addictive, sleep inducing drugs → CNS depressants and suppress pain. - Opium has more derivatives → opiates or opioids. - Most potent is heroin. - Only illegal narcotics are under illegal drugs (heroin). ## Controlled Substances - Include stimulants, some narcotics, depressants, anabolic steroids. - Schedule II → V. ## Stimulants - Highly addictive drugs that increase feelings of energy and alertness while suppressing appetite. - Side effects: High BP, rapid heart rate. - Extreme cases bleeding into the brain and death, depression once the effect wears off. - **Examples:** Amphetamines, methamphetamines, and cocaine. ## Methamphetamines - Synthetic drug that is longer acting and more potent than other stimulants. - Physical effects: major weight loss, severe dental problems, cardiac/neurological damage, hallucinations, multiple organ failure ## Legal Narcotics - Examples: Morphine (extreme pain), codeine (mild painkiller/cough suppressant), fentanyl, hydrocodone, oxycodone. - Drug deals do fent & heroin for potency. - Side effects: severe breathing problems, permanently contracted pupils, death from overdose. ## Narcan Spray (Naloxone) - Used for opioid emergency/overdose by blocking the heroin receptors. ## Depressants - Relieve anxiety and produce sleep. - Examples: Barbiturates and benzodiazepines. - Slow down body functions, reduce coordination and ability to concentrate. - Overdose leads to slurred speech, loss of coordination, coma, death. ## Anabolic Steroids - Promote cell and tissue growth and cell division. - Today is used to treat for: - Delayed puberty and muscle wasting. - Negative effects: acne, increased body hair, severe, include increased aggression, impaired fertility, cancers and heart attacks. ## Doping - Using substances like anabolic steroids to enhance athletic performance. ## Alcohol - CNS depressant, and while it isn’t on the 5 drug schedules, it can cause death. - # of alcohol is expressed in proof, which is 2x the percentage: - 80 proof = 40% alcohol. - Liver damage from converting alcohol → acetaldehyde. - Toxic. - Blood Alcohol Concentration (BAC) ≥ 0.08% - A person is considered under the influence of alcohol. - Combining heroin + alcohol → effects. ## Processing Evidence - Drug related evidence is collected ASAP as the body will break it down. ## Evidence Detection - K9 dogs trained to detect the smell of drugs and chemicals, used in airports and schools. - Chemical wanding of bags and hands for drugs in airports. - Drugs are smuggled through luggage, boxes, or large shipping containers, or people paid to smuggle them, called mules. ## Evidence Documentation and Collection - Sources of evidence: - Pills, powders, crystals. - Substances embedded in food, paper, candy - Seeds, leaves, mushrooms. - Evidence from victims: - Hair, urine samples, and if deceased, stomach contents. ## Evidence Packaging - Collectors should wear PPE and each piece of evidence must be packaged and labeled with the date and time. - To prevent mold and contamination all plant matter and wet items are dried. ## Forensic Analysis of Poisons, Toxins, Drugs ### Preliminary Testing - First responding officers can perform preliminary drug testing. - These drug tests use color change - color change meaning the drug is present. ### Confirmatory Testing - Multistep process to provide a positive identification of the drug. 1. Isolation of the substance. 2. Identification and separation of individual ingredients (qualitative). 3. Determination of quantity (quantitative). ## Thin Layer Chromatography - Travels through porous medium to separate compounds based on chemical affinity. ### Methods 1. Gas Chromatography: Identifies and separates components. 2. Mass Spectrometry: Molecules ions, separating and displaying each substance graphically. 3. Wet Chemistry: Uses liquid solvents to separate compounds. ## Tandem Mass Spectrometry - Quickly detects low traces of drugs in blood. ## Testing for Acute/Chronic Poisoning - **Acute poisoning:** High dose over a short period, that immediately produces symptoms. - **Example:** Cyanide ingestion, inhalation. - **Chronic poisoning:** Caused by lower doses over long periods of time. - **Example:** Mercury and lead poisoning. ## Duquenois-Levine - Chemical color test used to confirm the presence of cannabinoids in plant material. ## Quizlet - **Precursors:** Substances that can be converted into an abused substance. - **Cannabinoids:** Marijuana and parts of the plant in which tetrahydrocannabinol (THC) is active. - Active ingredient in marijuana. - **Polypharmacy:** Mixture of drugs. - **Cyanomethemoglobin:** A complex of cyanide and methemoglobin to treat cyanide poisoning. - Oxidized form of hemoglobin, can’t bind to oxygen and can’t carry oxygen to tissues. - **Carboxyhemoglobin:** Hemoglobin in which oxygen is replaced by carbon monoxide. - **Thermolabile:** A substance that breaks at elevated temperatures. - **ICP-MS:** Form of mass spectrometry used to detect inorganic materials and metals. ## Toxic/Pharmacokinetics vs. Toxic/Pharmacogenetics - **Toxic/Pharmacokinetics:** How genetic factors influence toxicology and drug effectiveness. - **Toxic/Pharmacogenetics:** Study of genetic influences on the response of organisms to toxins. ## Cutting Agents - Substance added to illicit drugs to reduce the concentration. ## Cystolithic (Bear-Claw Shaped) Hairs - Hairs on the surface of a leaf → finer clothing. ## Alkaloids - Substance formed by plant tissues/bodies of animals. - **Examples:** Morphine and codeine are alkaloids of opium from poppy plants. ## Mescaline - Hallucinogen in cactus buttons. ## Psilocybin - Naturally occurring psychedelic mushrooms produced by psilocybin mushrooms. ## Clandestine Drug Laboratories - Labs set up to manufacture controlled substances without government authorization. ## LD50 - Dose of poison that kills 50% of the population. ## Phencyclidine - Schedule I drug that causes users to experience severe psychotic manifestations. ## Designer Drugs - Drugs synthesized and designed for abuse and evasion of drug laws.