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Drugs & Toxicology
Chapters 9 & 10
Drugs
• Are natural or synthetic substances designed to affect the subject psychologically or physiologically
Narcotic Drugs
• Are analgesics, meaning they relieve pain by a depressing action on the central nervous system– Effects blood pressure, pulse rate, and
breathing rate
• Regular use can lead to physical dependence
• Most common narcotic drugs are the opiates
Heroin
• Morphine is readily extracted from opium and is used to synthesize heroin
• Addicts frequently dissolve heroin in water by heating it in a spoon and then injecting in the skin
• Heroin produces a “high” that is accompanied by drowsiness and a sense of well being that generally lasts 3-4 hours
Codeine
• Also present in opium, but it is usually prepared synthetically from morphine
Oxycontin
• Is not derived from opium or morphine
• It does have the same physiological effects on the body as do opium narcotics
• Is prescribed to a million patients for treatment with chronic pain
Methadone
• Is a well known synthetic opiate
• Is pharmacologically related to heroin
• Eliminates the addict’s desire for heroin while producing minimal side effects
Hallucinogens
• Marijuana is the most well known member of the class
• Cause marked changes in normal thought processes, perceptions, and moods
• Marijuana is the most controversial drug in this class because its long term effects on health are still largely unknown
Marijuana
• Refers to the preparation derived from the plant Cannabis
• The chemical substance largely responsible for the hallucinogenic properties of marijuana is tetrahydrocannabinol, or THC
• THC content varies in different parts of the plant, generally decreasing in the following sequence: resin, flowers, leaves, with little THC in the stem, roots, or seeds
Marijuana
• The THC rich resin is known as hashish
• Marijuana does not cause physical dependency, but the risk of harm is in heavy, long term use
Other Hallucinogens
• Include LSD, mescaline, PCP, psilocybin, and MDMA (ecstasy)
LSD
• Is synthesized form lysergic acid, and can cause hallucinations that can last for 12 hours
PCP
• AKA phencyclidine• Is often synthesized in clandestine laboratories
and is often smoked, ingested, or sniffed• Is often mixed with other drugs such as LSD or
amphetamine and is sold as a powder (angel dust), capsule, or tablet
• Oral intake of PCP first leads to feelings of strength and invulnerability, which may turn to depression, tendencies toward violence, and suicide
Depressants
• Are another class of drugs• Are substances used to depress the functions of
the central nervous system• Calm irritability and anxiety and may induce sleep• Include alcohol (ethanol), barbiturates,
tranquilizers, and various substances that can be sniffed, such as airplane glue, model cement, or aerosol gas propellants such as freon
Alcohol
• Enters the body’s bloodstream and quickly travels to the brain where it acts to suppress the brain’s control of though processes and muscle coordination
Barbiturates
• AKA downers
• Are normally taken orally
• Create a feeling of well being, relax the body, and produce sleep
Tranquilizers
• Produce a relaxing tranquility without impairment of high thinking faculties or inducing sleep
Sniffing
• Has immediate effects such as exhilaration, but impairs judgment and may cause liver, heart, and brain damage or even death
Stimulants
• Are substances taken to increase alertness or activity, followed by a decrease in fatigue and a loss of appetite
• Includes amphetamines, sometimes known as “uppers” or “speed”, and cocaine, which in its free base form is known as crack
Amphetamines
• Amphetamines and methamphetamines often are injected intravenously
• Cause an initial rush followed by an intense feeling of pleasure that is followed by a period of exhaustion and a prolonged period of depression
Cocaine
• Is extracted from the leaves of Erythroxylin coca
• Causes increased alertness and vigor, accompanied by the suppression of hunger, fatigue, and boredom
Crack
• Is cocaine mixed with baking soda and water, then heated
• Is often smoked in glass pipes, and like cocaine, stimulates the brain’s pleasure center
Club Drugs
• Refers to synthetic drugs that are used at nightclubs, bars, and raves
• Substances that are often used as club drugs include, but are not limited to, MDMA (ectasy), GHB (gamma hydroxybutyrate), Rohypnol (Roofies), ketamine, and methamphetamine
Ecstasy
• AKA methylenedioxymethamphetamine• Is a synthetic mind altering drug that exhibits
many hallucinogenic and amphetamine-like effects
• Enhances self awareness and decreases inhibitions• Seizures, muscle breakdown, stroke, kidney
failure, and cardiovascular system failure often accompany chronic abuse
GHB & Rohypnol
• Are central nervous system depressants that are often connected with drug facilitated sexual assault, rape, and robbery
Ketamine
• Is primarily used as a veterinary animal anesthetic that in humans causes euphoria and hallucinogens
• Can also cause impaired motor functions, high blood pressure, amnesia, and mild respiratory depression
Anabolic Steroids
• Are synthetic compounds that are chemically related to the male sex hormone testosterone
• Are often abused by individuals who are interested in accelerating muscle growth
• Side effects include unpredictable effects on mood and personality, depression, diminished sex drive, halting bone growth, and liver cancer
Toxicology
• Is the study of the adverse effects of chemicals or physical agents on living organisms
Toxicologists
• Toxicologists are charged with the responsibility for detecting and identifying the presence of drugs and poisons in body fluids, tissues, and organs
• Work in crime labs and medical examiners offices, but may also reach into hospital labs and health care facilities to identify a drug overdose or monitor the intake of drugs
Toxicology
• Toxic substances may– Be a cause of death– Continue to death– Cause impairment– Explain behavior
Aspects of Toxicology
• Dosage• The chemical or physical form of the substance• The mode of entry into the body• Body weight and physiological conditions of the
victim, including age and sex• The time period of exposure• The presence of other chemicals in the body or in
the dose
Lethal Dose
• LD50
• Refers to the dose of a substance that kills half the test population, usually within 4 hours
• Expressed in milligrams of substance per kilogram of body weight
Symptoms of Poisoning
Type of Poison Symptom/Evidence
Caustic poison (lye) Burns around the lips and mouth
Carbon monoxide Red or pink patches on chest & thighs
Sulfuric acid Black vomit
Hydrochloric acid Greenish-brown vomit
Nitric acid Yellow vomit
Phosphorus Coffee brown vomit, onion or garlic odor
Cyanide Burnt almond odor
Arsenic, mercury Pronounced diarrhea
Methyl (wood) or isopropyl alcohol Nausea, vomiting, unconsciousness, blindness
To Prove a Case
• Prove a crime was committed
• Motive
• Intent
• Access to poison
• Access to victim
• Death was caused by poison
• Death was homicidal
Forensic Autopsy
• Look for– Irritated tissues– Characteristic odors– Mees line
• Single transverse white bands on nails
• Order toxicological screens– Postmortem concentrations should be done at the scene
for comparison– No realistic calculation of dose can be made from a
single measurement
Human Specimens for Analysis
• Blood• Urine• Vitreous humor of eye• Bile• Gastric contents• Liver tissue• Brain tissue• Kidney tissue• Hair• Nails
Toxicology of Alcohol
• Alcohol, or ethyl alcohol, is a colorless liquid normally diluted with water and consumed as a beverage
• It is the most abused drug• Like any depressant, alcohol principally effects the
central nervous system, particularly the brain • 40% of all traffic deaths are alcohol related• About 5% is excreted unchanged in breath,
perspiration, and urine• 90% is detoxified by the liver
Toxicology of Alcohol
• Alcohol appears in the blood within minutes after it has been taken by mouth and slowly increases in concentration while it is being absorbed from the stomach and the small intestine into the bloodstream– It takes 30 –90 minutes for full absorption
Rate of Absorption
• Depends on – Time taken to consume the drink– The alcohol content– The amount of alcohol consumed– Food present in the stomach– Physiology of the consumer
Blood Alcohol Content
• The extent to which the individual may be under the influence of alcohol is usually determined by either measuring the quantity of alcohol present in the blood system or by measuring the alcohol content in the breath
• Is expressed as percent weight per volume of blood
• Legal limits in all states is 0.08%
Blood Alcohol Content
• Parameters affecting BAC– Body weight– Alcoholic content– Number of beverages consumed– Time between consumption
Blood Alcohol Content
• Burn off rate of 0.015% per hour but can vary– Male
• BAC Male= 0.071 x (# oz) x (% alcohol)/ body weight
– Female • BAC Female= 0.085 x (# oz) x (% alcohol)/body weight
Field Tests
• Preliminary tests– Used to determine the degree of suspect’s
physical impairment and whether or not another test is justified
• Psychophysical tests– 3 basic tests exist
• Horizontal gaze nystagmus (HGN)• Nine step walk and turn (WAT)• One leg stand (OLS)
Field Tests
• Horizontal gaze nystagmus (HGN– Follow a pen or small flashlight, tracking left to right
with one’s eyes– Wavering at 45 degrees indicates BAC of 0.10
• Nine step walk and turn (WAT)– Comprehend and execute two or more simple
instructions at a time
• One leg stand (OLS)– Maintain balance, comprehend and execute two or
more simple instructions at one time
The Breathalyzer
• More practical in the field• Collects and measures alcohol content of
alveolar breath• Breath sample mixes with 3 ml of 0.025%
potassium dichromate in sulfuric acid and water– Measures light absorption of potassium
dichromate before and after the reaction with alcohol
Controlled Substances
• Are drugs that are restricted by law
• Law was enacted in 1970 listing illegal drugs, their category and their penalty for possession, sale or use– Called Controlled Substances Act– Was created to prevent and control drug use
Controlled Substances Act
• Established 5 schedules of classification for controlled dangerous substances on the basis of a drug’s– Potential for abuse– Potential for physical and psychological
dependence– Medical value
Schedule I Drugs
• High potential for abuse
• No currently acceptable medical use in the US
• A lack of accepted safety for use under medical supervision
• Includes marijuana, heroin, ecstasy, and LSD
Schedule II Drugs
• High potential for abuse
• A currently accepted medical use with severe restrictions
• Abuse may lead to severe psychological or physical dependence
• Include cocaine, PCP, morphine, amphetamines, methamphetamines, ritalin
Schedule III Drugs
• Lower potential for abuse than the drugs in I or II
• A currently accepted medical use in the US• Abuse may lead to moderate physical
dependence or high psychological dependence
• Include all barbiturate prescriptions not covered under II, codeine, and anabolic steroids
Schedule IV Drugs
• Low potential for abuse relative to drugs in III
• A currently accepted medical use in the US• Abuse may lead to limited physical or
psychological dependence relative to drugs in III
• Include darvon, phenobarbital, and some tranquilizers such as diazepam (valium) and chlordiazepoxide (librium)
Schedule V Drugs
• Low potential for abuse relative to drugs in IV• Currently accepted medical use in the US• Abuse may lead to limited physical or
psychological dependence relative to drugs in IV• Include opiate drug mixtures that contain
nonnarcotic medicinal ingredients– Codeine found in cough medicine
Drug Identification
• The challenge or difficulty of forensic drug identification comes in selecting analytical procedures that will ensure a specific identification of a drug
• 3 ways to identify drugs– PDR- Physician’s Desk Reference– Field Tests- presumptive tests– Laboratory Tests- conclusive tests
What Can be Tested for Drugs
• Blood• Urine• Hair• Gastric contents• Bile• Liver tissue• Brain tissue• Kidney tissue• Spleen tissue• Vitreous humor of the eye
PDR
• Is used to identify manufactured pills, tablets, and capsules
• Is updated each year• Can be a quick and an easy identifier of the legally
made drugs that may be found at a scene• Reference book gives a picture of a drug, whether
it is a prescription, over the counter, or a controlled substance, as well as more detailed information about the drug
Presumptive Tests
• Include – Spot or color tests– Microcrystalline test
• A reagent is added that produces a crystalline precipitate which is unique for a certain drug
– Chromatography
Spot or Color Tests• 5 types
– Marquis• Turns purple in the presence of most opium derivatives and orange-
brown with amphetamine
– Dillie-Koppanyl• Turns violet-blue in the presence of barbiturates
– Duquenois-Levine• Turns a purple color in the presence of marijuana
– Van Urk• Turns blue-purple in the presence of LSD
– Scott test• Turns blue in the presence of cocaine
Confirmatory Tests
• Include – Spectrophotometry
• Ultraviolet (UV)
• Visible
• Infrared (IR)
– Mass spectrometry
Spectroscopy
• The interaction of electromagnetic radiation with matter
• Measured using a spectrophotometer– An instrument used to measure and record the
absorption spectrum of a chemical substance
Mass Spectrometry
• In a mass spectrometer, an electron beam is directed at sample molecules in a vacuum chamber
• The electrons break apart the sample molecules into many positive charged fragments– Are sorted and collected according to their
mass to charge ratio by an oscillating electric or a magnetic field