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Forensic Toxicology PowerPoint Presentation

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Description : Check out this medical PowerPoint presentation titled "Forensic Toxicology" by Robert Almeida, MS, D-ABFT-FT, TC-NRCC. This medical PowerPoint presentation talks about forensic toxicology, a branch of forensic science that deals with the investigation of drugs, chemicals, and other toxins in biological and non-biological specimens in order to determine their presence, concentration, and effects on the body. Forensic toxicologists work to identify and quantify drugs or other toxic substances in various specimens such as blood, urine, hair, and tissue samples. They also evaluate the effects of these substances on the human body, and determine the cause of death or illness in cases where toxic exposure is suspected.

Tags : Forensic Toxicology, nvestigation of drugs, chemicals, toxins in biological, Forensic toxicologists, toxic substances

Published on : Mar 15, 2023 | Views : 1336 | Downloads : 2

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Slide 1-

Forensic Toxicology Robert Almeida, MS, D-ABFT-FT, TC-NRCC Supervisor, Forensic Toxicology Rhode Island Department of Health
Slide 2-

Overview Introduction to FT Impaired Driving Program Local and National Statutes FT DUI Testing Protocol/ Process Analytical Instruments Pharmacology of Drugs and Ethanol
Slide 3-

Forensic Toxicology The analysis of biological specimens (ex. body fluids, tissues & organs) to determine the presence or absence of drugs and/or poisons for medico-legal purposes.
Slide 4-

Forensic Toxicology Did drugs and/or alcohol cause or contribute to an individual’s death or behavior?
Slide 5-

Forensic Toxicology Drugs and Poisons in Biological Samples Three Sub-disciplines: Post-mortem toxicology: Autopsy specimens Manner and cause of death Urine drug testing: Pre-employment or on the job drug use Drug maintenance program Human performance toxicology
Slide 6-

Human Performance Toxicology “Behavioral toxicology” How drugs influence human performance or behavior Physically and psychologically Legal consequences of alcohol and drug use Law Enforcement: Impaired-driving Drug facilitated sexual assault Other criminal acts while under the influence of a drug
Slide 7-

“Drunk” Driving Alcohol/ Ethanol Related Correlation between ethanol in the blood and the level of impairment Statutes: Motor Vehicle Offenses All fifty states Blood Alcohol Concentrations/ set measurements: Driving Under the Influence (DUI): 0.08% Driving While Impaired: 0.02% D.O.T./Federal: 0.04% Additional/Aggravated Offenses per Statutes Proposed legislation
Slide 8-

“Drunk” Flying March 2016 @ 7:00 AM Detroit to Philadelphia Fifty year old AA co-pilot arrested in the cockpit Operating an aircraft while under the influence of alcohol Legal limit: 0.04% Breathalyzer: 0.08% Misdemeanor
Slide 9-

Drugged Driving Laws All states have laws against drugged-driving *No set measurements for DUID. Why? Alcohol is a simpler compound and therefore processed more easily than drugs. No close link between blood and drug levels and measured impairment. Interactions occur with drug-drug and drug-alcohol combinations. Emergence of new designer drugs and their effects.
Slide 10-

Rhode Island DUID Statute Zero tolerance per se law Took effect July 1, 2006 Guilty of DUID: “…operates a vehicle while under the influence of any intoxicating liquor, drugs, or any controlled substance...” Guilty of DUID: “…blood presence of any controlled substances”
Slide 11-

DEA Controlled Substances Uniform Controlled Substances Act Categorize drugs according to their potential danger to the public Five tiers (I-V) Accepted medical use and potential for abuse/ dependence Include illicit and prescription drugs
Slide 12-

Impaired Driving Operation of a motor vehicle while under the influence of alcohol and/or drugs DUI, OUI, DWI, DUID Drugged driving: use of impairing substances: Illegal drugs Chemicals/Inhalants Misuse of prescription drugs Misuse of over the counter medications
Slide 13-

Effects of OH and Drugs on Driving Reaction time: increased or decreased Impaired judgement/decision making Impaired vision Inability to multi-task Impaired coordination Inability to process information or detect hazards
Slide 14-

Effects of Drugs on Driving Attention: Divided, not focused Tracking: Staying in lane of travel: Weaving/ Wrong-way Maintaining proper distance Perception: Predominately visual Environment Glare Dark and light
Slide 15-

Pharmacodynamics/ -kinetics Pharmacodynamics: The study of effects of drugs in the body “what a drug does to us” Categories
Slide 16-

Drug Classifications Classes of drugs and/or metabolites: CNS Stimulants CNS Depressants Narcotics Hallucinogens Inhalants Overlap with CNS effects
Slide 17-

CNS Stimulants Cocaine Amphetamine (Adderall), MDA (Sally), Methamphetamine, MDMA (Ecstasy, Molly) Methylphenidate (Ritalin) Schedule II drugs
Slide 18-

CNS Stimulants Physiological and psychological effects: Increased brain activity/alertness Quick speech/ movements Restlessness/ agitation/ fidgety/ pacing Hyperactivity Increased BP, HR Feelings of euphoria/ superiority/ paranoia Highly addictive Withdrawal symptoms
Slide 19-

Cocaine DUID Case 35 YO male driver PO observed MV approaching at a high rate of speed Estimated 60 mph Tailgating Aggressive behavior: Yelling and argumentative Dilated pupils Toxicology findings: Positive cocaine
Slide 20-

CNS Depressants Psychological/ Behavioral Effects: Sleeping, lessen anxiety Difficulty thinking and processing thoughts Impaired judgement Diminished concentration, memory, attention Drowsiness Physiological Effects: Slurred speech Increased reaction time Muscular incoordination/ loss of balance
Slide 21-

Ethanol/ Ethyl Alcohol C2H5OH Colorless liquid, generally diluted in water Most frequently seen drug in FTL CNS Depressant Potentiation with other CNS depressants, ex. narcotics, barbiturates, tranquilizers May mask other drugs present Blood alcohol level is proportional to the concentration of ethanol in the brain
Slide 22-

CNS Depressants Reduce anxiety, induce sleep, or dull senses Drugs: Barbiturates Benzodiazepines Narcotics Anti-histamines/Allery: Diphenhydramine (Benadryl) Sleeping aids- Ambien, Sominex Muscle relaxants- Soma, Flexeril Cold/Flu meds
Slide 23-

Benzodiazepines Anti-anxiety OCD Panic disorders Tablet or IV form Most commonly seen Rx med. Diazepam/ Valium Alprazolam/ Xanax Clonazepam/ Klonopin Benzene ring, Diazepine ring Long or short acting Designer “Benzos”
Slide 24-

Narcotic Analgesics Most commonly prescribed drug Potent painkillers Opiates/ Opioids Strong CNS depressants Highly addictive Sedation/ sleepiness, nodding off Respiratory suppression Receptors Schedule II Schedule I
Slide 25-

Opiates/ Opioids Rx or illicit: Morphine/ heroin Codeine Oxycodone Hydrocodone Methadone Tramadol Fentanyl Fentanyl analogs
Slide 26-

Zolpidem Prescription Drug Trade name: Ambien CNS depressant Fast acting sedative hypnotic Prescribed for short-term treatment of insomnia Dose taken immediately before bedtime Do not take with alcohol or CNS depressants DEA Schedule IV controlled substance Known to cause sleep-walking, -eating, -driving Top 10 drugs found in impaired motorists
Slide 27-

Zolpidem DUI Case 2014 Fifty-four year old female Reports of a MV operator driving over neighborhood lawns and striking her SUV into her garage Officers report female sitting in the driver’s seat with the engine running and MV pinned up against the garage door The gear was in “Drive” Driver staring straight ahead in a trance-like state. PO request that the SUV be put into “Park” and she stated “It is and my friend is driving”
Slide 28-

Zolpidem DUI Case 2014 She then put the SUV into reverse. Disoriented Mumbled speech Incapable of answering simple questions Unsteady on her feet Denied using alcohol or drugs that day Toxicology finding: Negative alcohol Positive Zolpidem Repeat offender from two years prior
Slide 29-

Inhalants Chemical products More frequently used by younger people “Huffing” Used to change one’s mental state Effects on driving: Impaired thought process Hallucinations Delusions Dizziness Muscular incoordination Disorientation
Slide 30-

Inhalants Glue Gasoline Paint thinner Dust-off Sharpies Spray Paint Nitrous oxide
Slide 31-

“Huffing” Case 23 YO male driver Slumped over steering wheel Driving through a parking lot A witness honked her horn Accelerated the MV, went over a curb, and hit a parked car PO found computer dusting spray Toxicology finding: 1,1-difluoroethane
Slide 32-

Hallucinogens Altered perception of reality Visual Auditory Emotions Marijuana (THC) Synthetic Cannabinoids Bath Salts LSD PCP Psilocybin/ Psilocin
Slide 33-

Marijuana Cannabis plant THC active component Hashish, hash oil Smoked or eaten Used for treating chronic pain and nausea Addictive Withdrawal Attributed to decreased motivation Increased inactivity Hallucinogen and CNS depressant
Slide 34-

Marijuana Targets cannabinoid receptors in the brain: Effect: Perception Memory Mood Sleep Appetite Most frequently found illicit drug in drivers involved in a motor vehicle accident
Slide 35-

Pharmacodynamics/ -kinetics Pharmacodynamics: The study of effects of drugs in the body “what a drug does to us” Pharmacokinetics: The study of drugs in the body “what we do to a drug” ADME:
Slide 36-

Absorption- Ethanol Alcohol appears in the blood within minutes after consumption: Stomach and small intestines Complete in generally 30-90 minutes Maximum BAC is reached Post-absorption
Slide 37-

Absorption Rate- Ethanol Depends on: Amount of alcohol consumed Type of drink Time of consumption Presence of food in the stomach Health of the individual
Slide 38-

Absorption- Drugs Most concentrated at the point of entry Routes of administration: Oral: GI tract, stomach, intestines, and liver Inhalation: Through the lungs; “huffing” solvents, gases, smoking Rapid absorption Intravenous: Most efficient; drug administered directly into the bloodstream; bypass the stomach and liver
Slide 39-

Absorption- Drugs Intranasal: Insufflation; snorting; cocaine, heroin Intramuscular: Less efficient; slower transfer to the bloodstream Sublingual: Oral mucosa, tongue Rapid absorption Dermal: Patches: fentanyl, nicotine
Slide 40-

Distribution Ethanol: Carried to watery parts of the body Blood, brain, vitreous humor Transfer from blood into the tissues Distributes to heart, liver, kidney, and brain Muscle and fat more slowly Volume of distribution: theoretical value Vd= D/C Ex: Alcohol: <1; Amitriptyline: 11-18
Slide 41-

Metabolism Process of altering the drug to eliminate it from the body Detoxification process Primarily in the liver Phase I: Transform functional groups May form other active compounds (metabolites) Ex. Diaxepam/ Valium; Nordiazepam Phase II: Mostly inactive, water soluble compounds
Slide 42-

Elimination Excretion Final removal from the body Kidney and liver Exception: EtOH: also eliminated through the lungs and sweat Drugs also eliminated into breast milk Elimination rates: Zero order: constant amount cleared from the blood per unit time; ex. EtOH First order: constant fraction of drug is removed from the blood per unit time; half-lives
Slide 43-

Elimination- Ethanol Oxidation: Liver enzymes 95% to CO2 and water Excretion: 5% unchanged state Breath, sweat, and urine Amount of alcohol exhaled in breath is proportional to BAC Henry’s Law 2100:1 mL
Slide 44-

The Process of a RI DUID Case Establish probable cause: Observation of improper driving or equipment violation by a PO Evaluation /interview of the driver Standardized Field Sobriety Tests performed outside of MV Blood collection Blood samples taken and submitted to the FTL
Slide 45-

Blood vs. Urine Blood specimen necessary to determine impaired driving Blood is circulating throughout the body In equilibrium with the brain Present in the CNS Urine is an end-product of biological processes: Absorption, Distribution, and Metabolism Pooled sample over time Drugs present for days-weeks May not be present in the blood
Slide 46-

Blood vs. Breath Breath is an easily obtainable, non-invasive sample for testing alcohol use. Provides a fast and accurate result. Breathalyzer instrument cannot detect drugs
Slide 47-

FTL Evidence
Slide 48-

Specimen Tubes
Slide 49-

DUI Scope of Testing Ethanol/Volatiles/Inhalants Drugs: 2 steps Preliminary screening Presumptive result Classes of drugs Confirmatory testing: Specific/directed testing Two different test methods necessary to report a positive result
Slide 50-

Alcohol Testing Headspace Gas chromatography Separation technique Partition effect: Stationary phase Mobile phase Flame ionization detector RT Well established and accepted Highly specific and sensitive
Slide 51-

Gas Chromatograph
Slide 52-

GC Volatiles Chromatogram
Slide 53-

Headspace Gas Chromatograph
Slide 54-

Terminology Sensitivity: Measure of the method’s ability to detect an analyte Distinquish true negatives from true positives Limits of detection and quantification Specificity: Measure of the method’s ability to correctly identify an analyte Cross-reactivity Ex. Immunoassays, Confirmatory tests
Slide 55-

Forensic Drug Testing A two step process: Preliminary screening: Immunoassay Confirmatory testing: GC GC/MS LC/MS Well established and accepted techniques
Slide 56-

Comprehensive Drug Testing Classes of drugs and/or metabolites: CNS Stimulants CNS Depressants Narcotics Hallucinogens Inhalants Illicit and Rx
Slide 57-

Prescription and OTC Drugs Anti-depressants Anti-psychotics Muscle relaxants Anti-seizure Cardiovascular Cold/Flu Meds Cough syrups Anti-histamines Sleeping aids
Slide 58-

Preliminary Tests First step in forensic drug testing “Immunoassay” Presumptive Screens Qualitative assays Classes of drugs Disadvantages: Limited scope of testing False negatives and positives are possible Not forensically defensible without confirmation
Slide 59-

ELISA Test Enzyme linked immunosorbent assay Competitive binding Antibody-Antigen reaction Advantage: Automated High sensitivity Applicable to blood and post-mortem specimens Disadvantage: Low specificity
Slide 60-

ELISA Screening Test Antibody-Antigen Reaction
Slide 61-

ELISA Process Antibody coated plates Sample + Conjugate Incubation/ competitive binding Wash Substrate Reader Measures absorbance of conjugate in sample and standards Inversely Proportional
Slide 62-

ELISA Principle
Slide 63-

ELISA Preliminary Testing
Slide 64-

ELISA Tecan System
Slide 65-

Confirmatory Testing Second phase of forensic drug testing All positive screening tests require confirmatory test utilizing a more specific and sensitive chemical principle. Qualitative or quantitative analysis Gas or liquid chromatograph Mass spectrophotometer detector GC/MS or LC/MS
Slide 66-

Confirmatory Testing Detect and identify specific drugs present Broad scope of analytes, including metabolites Detect minute amounts Forensically defensible Widely accepted methodology Extensive scientific literature and information Requires separation of the drug from the sample matrix Labor intensive Expensive instrumentation
Slide 67-

Analytical Overview Blood specimen Isolate the drug/analyte of interest Chemical property of the drug Liquid-liquid extraction Solid phase extraction Analysis: HPLC, GC, GC/MS Data Processing/Review/Interpretation
Slide 68-

Liquid-liquid Extraction Most frequently used technique pH adjustment with buffer, acid, or base Extract with an organic solvent Hexane, chloroform, dichloromethane Property of the drug of interest: ? Acidic, neutral, or basic drug/ functional groups Good recoveries but time consuming
Slide 69-

Solid Pase Extraction Commercially prepared columns Contains sorbent/ resin/ silica Series of steps Acid, neutral, basic drugs Fully automated Analyze
Slide 70-

Solid Pase Extraction
Slide 71-

Solid Phase Auto-extractor
Slide 72-

Mass Spectrometer Detector Coupled with GC or LC Identifying technique Inlet, electron ionization, bond breaking and fragmentation, analyzer, detector Resulting in a drug “fingerprint” MS database/ library Highly accurate, sensitive, and specific
Slide 73-

GC/MS System
Slide 74-

GC/MS TIC SKF-525A: Proadifen Internal Standard 2 unknown peaks
Slide 75-

GC Mass Spectra GC/MS Cocaine chromatogram
Slide 76-

GC/MS System
Slide 77-

Interpretation A toxicologist can: Test the sample Interpret the analytical result Testify clearly to the effects of drug present in the driver
Slide 78-

Interpretation A toxicologist cannot: Determine impairment in a specific individual from a single blood result Determine how much drug was taken Determine exactly when a drug was taken
Slide 79-

Interpretation Is the driver impaired? Cannot give an opinion based solely on positive toxicology results Need information gathered by the investigator at the scene Observations, situation, environment, SFSTs
Slide 80-

Drug Interpretation Issues No legal guidelines Case-by-case basis Polypharmacy/multiple drug use: Synergistic effect with other like drugs Mixed classes Individual tolerance Metabolites
Slide 81-

2018 Toxicology Stats 188 DUI cases submitted 96.3% DUI cases positive for ethanol or drugs 50% Positive Ethanol Ave. BAC= 0.18 g% ethanol 66% Positive Drugs Drugs: THC, Fentanyl, Cocaine, Methadone, Benzodiazepines 22%: Ethanol + Drugs
Slide 82-

Conclusion Individual impairment increases as a drug’s concentration increases in the body Ethanol and drugs effect a driver’s ability to safely operate a MV and increase the risk of a MV crash Do not mix alcohol and drugs
Slide 83-

Robert Almeida, MS, D-ABFT-FT, TC-NRCC Supervisor, Forensic Toxicology 401.222.5565 robert.almeida@health.ri.gov