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Chapter 7 - Drugs

Chapter 7 - Drugs. Forensic Science. Drugs. A drug is a natural or synthetic substance that is used to produce physiological or psychological effects in humans or other higher-order animals. Drug Dependence.

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Chapter 7 - Drugs

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  1. Chapter 7 - Drugs Forensic Science

  2. Drugs • A drug is a natural or synthetic substance that is used to produce physiological or psychological effects in humans or other higher-order animals.

  3. Drug Dependence Psychological Dependence: conditioned use of a drug caused by underlying emotional needs Physical Dependence: Physiological need for a drug that has been brought about by its regular use. Characterized by withdrawal sickness when administration of drug is abruptly stopped.

  4. Factors that influence dependence • Physiological factors: • nature of the drug • route of administration • dose • frequency of administration • the individual’s rate of metabolism • Nondrug factors: • personal characteristics of the user • His/her expectations about the drug experience • society’s attitudes & possible responses • the setting in which the drug is used.

  5. Types of Drugs • Narcotics • Depressants • Stimulants • Club Drugs (Usually either stimulants or depressants) • Hallucinogens • Anabolic Steroids

  6. 1) Narcotic Drugs Narcotic: analgesic or pain-killing substance that depresses the central nervous system & vital body functions • From Greek word “narkotikos” which implies a state of lethargy or sluggishness • Relieves pain or induces sleep • Repeated use will produce physical dependence • Ex: morphine, codeine, heroin

  7. Narcotic Drugs cont. • The most common source for narcotic drugs is opium. • Morphine is extracted from opium & used to synthesize heroin.

  8. A) Heroin • Heroin is the opium derivative most frequently used by addicts. • It usually is injected intravenously because by injection its effects are felt almost instantaneously and with maximum sensitivity. • In addition, heroin’s high solubility in water makes its street preparation for intravenous administration rather simple.

  9. Narcotic Drugs cont. • Opiates are not derived from opium or morphine, but they have the same physiological effects on the body. Ex. methadone and oxycontin (oxycodone) • Methadone: synthetic opiate which reduces desire for heroin with minimal side effects

  10. 2) Depressants Depressants: substance used to depress the functions of the central nervous system, calm irritability and excitability, and they may induce sleep. • Alcohol (ethanol) • Barbituates • Tranquilizers • Sniffing of volatile solvents (ex. airplane glue, model cement)

  11. A) Alcohol (ethynol) • Reactions vary with user, but range from inhibited mental processes, slowed reaction times, personality changes, death, etc. • Most widely used and abused drug

  12. A) Alcohol cont. • Low doses of alcohol tend to inhibit the mental processes of judgment, memory, and concentration. • At low to moderate doses alcohol causes the user to become expansive and exude confidence, reduces coordination substantially, inhibits orderly thought processes and speech patterns, and slows down reaction time.

  13. B) Barbituates • Downers • They relax, create a feeling of well-being and produce sleep • Can produce physical and psychological dependence • Ex. Quaaludes – a sedative and muscle relaxer • Often used in medicine and usually taken as a pill

  14. C) Tranquilizers • Differ from barbituates in their action on central nervous system • They produce tranquility without impairment of high-thinking faculties or inducement of sleep. • Can cause physical and psychological dependence • Ex. Valium

  15. D) “Glue” sniffing • Sniffing volatile solvents • Are central nervous system depressants • Feeling of exhiliration and euphoria combined with impairment of function • Is very dangerous, not known if actually physically addictive

  16. 3) Stimulants • Stimulate central nervous system • Substance taken to increase alertness or activity • Many are physically and psychologically addictive • Depression may set in after stimulant wears off • Amphetamines (uppers, speed) • Methamphetamine & crystal meth • Diet Drugs • Cocaine

  17. Stimulants cont. • The two most commonly abused illegal stimulants are amphetamines and cocaine. • Their smokable forms are ice and crack, respectively. • Smoking causes a more intense drug experience than “snorting” because it causes the drug to enter the bloodstream more quickly and to reach the brain faster.

  18. A) Amphetamines • Uppers • Speed • Synthetically produced • Does not occur naturally

  19. A) Amphetamines cont. • Methamphetamines & crystal meth • very prevalent today • causes remarkable physical damage • can be manufactured easily https://www.youtube.com/watch?v=cWaWyalaAag https://www.youtube.com/watch?v=GwvXayKrCvE https://www.youtube.com/watch?v=j5SXjgrJITY

  20. B) Diet drugs • commonly used • many are legally obtained • ex. Phen-fen, dexatrim, etc • some have permanent adverse effects on the body, especially the heart

  21. C) Cocaine • Extracted from leaves of cocoa plant • Once used as anesthetic • Widely used, physically and psychologically addictive

  22. Cocaine cont. • Generates confidence, increased alertness • Sigmund Freud experimented with it. • Cocaine in its freebase form is called crack. • Crack = cocaine mixed with baking soda & water, then heated, dried, & broken into chunks & smoked

  23. Cocaine cont. • It is actually classified as a narcotic under current federal law due to its use in medicine years ago. • However, cocaine is actually a powerful central nervous system stimulant, whereas narcotics are analgesic or pain-killing substances that exert a depressant effect on the central nervous system.

  24. ** Club Drugs (stimulants & depressants) • Synthetic drugs that are used at nightclubs, bars, and raves (all-night dance parties). • Some act as stimulants; others as depressants . Examples: • MDMA(Ecstasy) • GHB (gamma hydroxybutyrate) • Rohypnol (“roofies”) • ketamine, • methamphetamine

  25. ** Club Drugs cont. • GHB and Rohypnol are central nervous system depressants that are often connected with drug-facilitated sexual assault, rape, and robbery. Both drugs are odorless, colorless, and tasteless and so will remain undetected when slipped into a drink. • The most popular club drug is Ecstasy. Health effects associated with chronic use include seizures, muscle breakdown, stroke, kidney failure, cardiovascular system failure, and damage to the areas of the brain responsible for thought and memory.

  26. 4) Hallucinogens • Drugs that cause marked alterations in normal thought processes, perceptions, and moods • Marijuana • LSD • MDMA ( Ecstasy) • PCP (Phenocyclidine or Angel Dust) • Psilocybin (mushrooms) • mescaline

  27. Marijuana • From the Cannibis plant • secretes a sticky resin = hashish • has been used legally and illegally for 3000 years • grows wild 5-15 feet tall • Most widely used illicit drug in the US • Prior to 1970, marijuana was classified as a narcotic drug.

  28. Marijuana cont. • THC (tetrahydrocannibinol): Amount varies among plants and within one plant. • Potency depends on its form • Highest to lowest = resin, flowers, leaves, stems, roots, and seeds • May have medicinal uses such as glaucoma, lessen nausea caused by anti-cancer drugs

  29. Marijuana cont. • At low doses the user may experience: • an increased sense of well-being • initial restlessness and hilarity followed by a state of relaxation • alteration of sensory perceptions • a more vivid sense of touch, sight, smell, taste, and sound • feelings of hunger • subtle changes in thought formation and expression

  30. Marijuana cont. • Two botanical features used to identify marijuana include: • short “bear claw” hairs on the upper side of the leaf • longer, nonglandular hairs on the other side • If microscopic examination cannot be obtained, thin-layer chromatography is often used to identify marijuana.

  31. LSD • Lysergic acid diethylamide • synthesized from lysergic acid derived from ergot which is a type of fungus that attaches to certain grasses and grains • described by chemist Hoffman in 1943 after he accidentally ingested some • question of whether has impact of chromosomes of offspring

  32. MDMA - Ecstasy • originally patented as an appetite suppressant • some severe adverse reactions

  33. PCP - Phenocyclidine • synthesized • often mixed with other drugs • sold as angel dust • variety of responses, many violent and aggressive

  34. 5) Anabolic Steroids • Synthetic compounds that promote/accelerate muscle growth • chemically related to male hormone, testosterone • Harmful physical side effects and may affect mood and/or behavior

  35. Drug Control Laws • Controlled Substance Act • Federal law establishes 5 schedules of classification for controlled dangerous substances based on drugs potential for abuse, potential for physical and psychological dependence, and medical value • Penalties for possession, use, sale, etc. are related to classification schedule

  36. Drug Class Schedules • Schedule I drugs have no accepted medical value in the United States; schedule II drugs may have medical use with severe restrictions. • Drugs deemed to have the highest potential for abuse and having a current medical use are listed in the II schedule of the Controlled Substances Act. • The tranquilizers Valium and Librium are classified in the IV schedule of the Controlled Substances Act.

  37. Drug Possession Penalties • A controlled substance analog is a chemical substance substantially similar in chemical structure to a controlled substance. They are considered schedule I drugs to combat the proliferation of “designer drugs”—substances that are chemically related to some controlled drugs but are not listed under schedule I. • A precursor is a chemical compound used by clandestine drug laboratories to synthesize drugs of abuse. The Controlled Substances Act provides severe penalties for a person who possesses a listed precursor chemical with the intent to manufacture a controlled substance. Precursors to PCP, amphetamines, and methamphetamines are regulated in the same manner as Schedule II substances.

  38. Drug Identification • Difficulty lies in selecting the correct analytical procedures to allow for identification • 1st perform screening tests • 2nd perform confirmation tests

  39. Screening Tests • Analysts employ screening tests to determine the identity of drugs present in a sample. • non-specific and preliminary in nature • reduce the number of possible drugs to a small and manageable number • Ex. Color test, microcrystalline tests

  40. Color Tests • A series of color tests produce characteristic colors for the more commonly encountered illicit drugs. • Marquis - opium derivatives; purple • Dillie-Koppanyi - barbituates; violet blue • Duquenois-Levine - marijuana; purple • Van Urk- LSD; blue-purple • Scott Test - cocaine; blue-pink to blue

  41. Microcrystalline Tests • a drop of a chemical reagent added to a small quantity of drug on a microscopic slide produces crystals that are highly characteristic of the drug • Two advantages of these tests are that they are rapid and they often do not require the isolation of a drug from its diluents.

  42. Identification Tests • After preliminary testing, forensic chemists employ more specific tests to identify a drug substance to the exclusion of all other known chemical substances. • Confirmation- a single test that specifically identifies a substance • Infrared spectrophotometry and mass spectrometry typically are used to specifically identify a drug substance.

  43. Chromatography • requires comparison between questioned and known drugs • analyst must have some idea as to the identity of illicit material before using the test • most satisfactory way of simultaneously separating and tentatively identifying drugs

  44. Spectrophotometry • selective absoprtion of light by drugs • Ultraviolet spectrophotometry is a useful technique for establishing the probable identity of a drug. • Infrared spectrophotometry is one of the few analytical techniques available to the chemist that can specifically identify a substance.

  45. Mass spectrophotometry • combines gas chromatography and mass spectrophotometer • allows examiner to separate components of complex drug mixture and unequivocally identify each substance present in the mixture

  46. Identification of Marijuana • possesses botanical features • cystolithic hairs on leaves • color test • thin layer chromatography

  47. Collection & Preservation of Drug Evidence • Evidence should be properly packaged, and labeled • Prevent loss of evidence and cross-contamination • Supply background information

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