Presentation on theme: "Drugs and Toxicology Forensic Science Glatt 2013-2014."— Presentation transcript:
Drugs and Toxicology Forensic Science Glatt 2013-2014
Drugs Drug- a natural or synthetic substance designed to affect humans (or other animals) either psychologically (mind), physiologically (body) or BOTH. – Non-controlled Substances- Over-the Counter and/or age restricted yet legal substances Legal does not imply safe or non-addictive – Must use as directed and can be addictive (Caffeine, Tylenol PM, Nicotine, Alcohol ect…) Examples: Aspirin, Cough Medicines, nicotine, alcohol ect… – Controlled Substances- drugs whose sale, possession, and use are restricted because of the potential for psychological and physical dependence and abuse. Examples Include: Heroin (I), Cocaine (II), Anabolic Steroids (III), Xanax (IV), and Codeine (V) ect…
Drug Dependence Psychological Dependence- need or desire to use drug to create a sense of well-being and to escape from reality – Seek relief from social or emotional stress – May increase with increased use Physical Dependence- physiological illness or withdrawal effects result from not having the drug – Generally considered more severe and can be life threatening – Illness is due to withdrawal effects Body builds tolerance and adjusts to drug being present in system Body is thrown out of “equilibrium” without drug present – Phys. Dependence will increase with increased use – Withdrawal effects Includes chills, vomiting, stomach cramps, convulsions, insomnia, pain, hallucinations and even death Onset, severity, and duration of psychological and physiological dependency varies from drug to drug and from person to person
Classification of Controlled Substances Schedule I—high potential for abuse; no currently accepted medical use in the U.S.; a lack of accepted safety for use under medical supervision Examples: heroin (diacetylmorphine), LSD, marijuana, ecstasy (MDMA) Schedule II—high potential for abuse; a currently accepted medical use with severe restrictions; abuse may lead to severe psychological or physical dependence Examples: cocaine, morphine, amphetamines (including methamphetamines), PCP, Ritalin Schedule III—lower potential for abuse than the drugs in I or II; a currently accepted medical use in the U.S.; abuse may lead to moderate physical dependence or high psychological dependence Examples: intermediate-acting barbiturates, anabolic steroids, ketamine
Classification of Controlled Substances Schedule IV—low potential for abuse relative to drugs in III; a currently accepted medical use in the U.S.; abuse may lead to limited physical or psychological dependence relative to drugs in III Examples: stimulants and depressants including Valium, Xanax, Librium, phenobarbital, Darvon Schedule V—low potential for abuse relative to drugs in IV; currently accepted medical use in the U.S.; abuse may lead to limited physical or psychological dependence relative to drugs in IV Examples: codeine found in low doses in cough medicines
Hallucinogens Hallucinogens- substances that can change normal thought processes, perceptions, and moods – Many are derived from plants – Examples Marijuana (most common) LSD, PCP, Mescaline Ketamine (Special K) MDMA or Ecstasy, GHB, Rophenol or Ruffies (date rape drug) – Affects of an overdose often include Increased heart rate Increased blood pressure Panic attacks, anxiety, or psychosis
Narcotics Narcotics- are analgesics or substances that relieve pain by suppressing the central nervous system. – Highly addictive – Includes Opium and its derivatives, heroin (“horse” or “smack”) and codeine – Hydrocodone (Vicodin, Lortab), methadone, morphine, oxycodone (Percocet, OxyContin) and Tylenol 3 (acetaminophen and codeine) are man-made narcotic painkillers that are often abused Most are prescribed yet controlled substances – Effects of overdose are related to slowed central nervous system Difficulty breathing, low blood pressure, confusion, sleepiness, clammy skin, small pupils, coma, and death
Stimulants Stimulant- are substances that increase the actions of the central nervous system – Highly addictive – Increased energy, alertness – Suppressed appetite and fatigue – Increased anxiety and depression when drug wears off Overdose affects include high blood pressure, agitation, confusion, seizures – Examples include caffeine, nicotine, amphetamines ( uppers or “bennies”, methamphetamine (“speed” or “crank”), cocaine, and crack (recrystallized cocaine)
Anabolic Steroids Anabolic Steroids- are substances that promote cell division and tissue growth – Created in laboratory Originally used to treat hypogonadism (condition in which testes produce low amounts of testosterone) Also currently used to treat delayed puberty, impotence, and muscle wasting caused by HIV infection. – Commonly used illegally and abused by weightlifters and other athletes. – Mild side effects include increased acne, increased body hair, balding – Severe side effects include high blood pressure, increased cholesterol levels, impaired fertility in males, blood clotting, kidney and liver cancers, and heart attacks
Depressants Depressants- are substances that decrease the action or suppress the central nervous system. – Often prescribed to lower anxiety or promote sleep – Reduce body functions by increasing the activity of the neurotransmitter (brain chemical) called GABA – Examples include alcohol, barbituates, benzodiazepines – Side effects include slurred speech, loss of coordination, and state of intoxication similar to that of alcohol – Overdose may slow heart rate, breathing rate, and cause coma or death
Drugs and Crime In US, as much as 75 % of evidence being examined in forensic laboratories is considered drug related – Either drugs themselves or evidence from drug related crimes
TOXICOLOGY Forensic toxicology- is the combined study of chemistry, biology, and physiology concerned with the study of the adverse effects of chemicals on living organisms. – A toxicologist is a scientist or medical personal who specializes in the study of symptoms, mechanisms, treatments and detection of drugs, toxins, and venoms in the body Cause and effect relationship of ingesting drugs, toxins or venoms is also determined – State of inebriation due to alcohol or drug use – Poisoned or natural caused death – Role or influence of alcohol or drugs in a perpetrator or victims actions also studies the harmful effects of chemical, biological and physical agents in biological systems that establishes the extent of damage in living organisms.
Forensic Toxicology Postmortem—medical examiner or coroner Criminal—motor vehicle accidents (MVA) Workplace—drug testing Sports—human and animal Environment—industrial, catastrophic, terrorism
Aspects of Toxicity Toxicity- the degree to which a substance is poisonous or can cause injury, or has an effect upon someone (drugs) 1. Dosage or concentration 2. The chemical or physical form of the substance 3. The mode of entry into the body 4. Body weight and physiological conditions of the victim, including age and sex 5. The time period of exposure 6. The presence of other chemicals in the body or in the dose SYNERGIZING EFFECT – 2 Drugs mixed together leads to an increased effect of both drugs when taken separately – Alcohol and other depressants – Dangerous risk of overdose
Lethal Dose LD 50 refers to the dose of a substance that kills half the test population, usually within four hours Expressed in milligrams of substance per kilogram of body weight
Human Specimens for Analysis Blood Urine Vitreous humor of eyes Bile Gastric contents Liver tissue Brain tissue Kidney tissue Hair/nails
Techniques Used in Testing Acid or Base – Initial test can narrow down the type of substance or drug present.
Techniques Used in Testing SCREENING TESTS – Presumptive Tests – chemical indicators are used to test for the possible presence of certain drugs Indicators detect and “indicate” the possible presence of drug or poison by turning a specific color – Marquis Solution (formaldehyde in sulfuric acid) » Turns purple in presence of heroin, morphine, and most opium derivatives (narcotics) » Also turns orange-brown when mixed with amphetamines and methamphetamines – Dillie-Koppanyi » Turns violet-purple in presence of barbituates – Duquenois-Levine » Turns purple in the presence of marijauna – Van Erk (3 solution test) » Turns blue purple in the presence of LSD (“acid”) – Scott Test (3 solution test) » Indicates or detects cocaine – Thin-Layer Chromatography – Gas chromatography – Thin Layer Chromatography Screening tests are not admissible in court as certain substances can result in false positives. Initial screening tests are therefore followed by confirmatory tests
Techniques Used in Testing Confirmation Tests Gas Chromatography/Mass Spectrometry – Gas Chromatography- used to separate the individual compounds in a mixture or solution – Mass Spectroscopy- used to conclusively identify unknown samples. Compounds are bombarded with a stream of electrons causing them to break apart into fragments Mass to charge (M/Z) of each fragment is measured and graphed
Alcohol—Ethyl Alcohol (C2H5OH) Most abused drug in America About 40 percent of all traffic deaths are alcohol-related Toxic—affecting the central nervous system, especially the brain Colorless liquid, generally diluted in water Acts as a depressant Alcohol appears in blood within minutes of consumption; 30–90 minutes for full absorption Detoxification—about 90 percent in the liver About 5 percent is excreted unchanged in breath, perspiration, and urine
BAC: Blood Alcohol Content Expressed as percent weight per volume of blood Legal limit in all states is 0.08 percent Parameters influencing BAC: Body weight Alcohol content Number of beverages consumed Time since consumption – Alcohol is metabolized at a rate of approximately 1 drink per hour.
BAC Calculation Blood Alcohol Content.08 legal limit Male BAC = Female BAC = 0.071 (oz) (% alcohol) body weight 0.085 (oz) (% 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—three basic tests: Horizontal gaze nystagmus (HGN): follow a pen or small flashlight, tracking left to right with one’s eyes. In general, wavering at 45 degrees indicates 0.10 BAC. Nine-step walk and turn (WAT): comprehend and execute two or more simple instructions at one time One-leg stand (OLS): maintain balance; comprehend and execute two or more simple instructions at one time