What Can Dead People Tell Us? Postmortem Toxicology for Attorneys

Transcription

1 What Can Dead People Tell Us? Postmortem Toxicology for Attorneys Dr. Allison A. Muller Diplomate, American Board of Applied Toxicology Principal/Owner: Acri Muller Consulting, LLC Learning objectives List 3 things that happen to the body after death that relate to drugs Define the terms pharmacokinetics and pharmacodynamics Explain one way that postmortem changes affect drug levels State one example of how a drug level cannot be tied to a cause of death State one example of how a drug level can be tied to a cause of death 2 1

2 First some definitions Pharmacokinetics 3 First some definitions Pharmacodynamics 4 2

3 First some definitions Volume of distribution 5 First some definitions Lipophilicity 6 3

4 Changes to the body after death 7 Postmortem redistribution (PMR) the basics 8 4

5 Sources of drug levels Vitreous humor Urine Bile Tissue Blood Femoral Heart May be ante mortem (hospital blood) 9 Example of test results Detailed Findings: Analysis and Comments Result Units Rpt. Limit Specimen Source Analysis By Caffeine Positive mcg/ml Hospital Blood LC/TOF MS Nicotine Positive ng/ml Hospital Blood LC/TOF MS Amphetamine 66 ng/ml Hospital Blood LC MS/MS Methamphetamine 180 ng/ml Hospital Blood LC MS/MS Other than the above findings, examination of the specimen(s) submitted did not reveal any positive findings of toxicological significance by procedures outlined in the accompanying Analysis Summary. 10 5

6 Units of measurement Weight Abbreviation Conversion Factor Gram G 1 g = 1000 mg Milligram mg 1 mg = 1000 mcg = g Microgram Mcg 1 mcg = mg = g Kilogram Kg 1 kg = 1000 g 11 Know the menu for toxicology testing 12 6

7 Example of test results Analysis Summary of Reporting Limits: All of the following tests were performed for this case. For each test, the compounds listed were included in the scope. The Reporting Limit listed for each compound represents the lowest concentration of the compound that will be reported as being positive. If the compound is listed as None Detected, it is not present above the Reporting Limit. Please refer to the Positive Findings section of the report for those compounds that were identified as being present Acode 52409B Amphetamines Confirmation, Blood (Forensic) Hospital Blood Analysis by High Performance Liquid Chromatography/TandemMass Spectrometry (LC MS/MS) for: Compound Amphetamine Ephedrine MDA MDEA Methamphetamine Norpseudoephedrine Rpt Limit 10 ng/ml Compound Phendimetrzine Phenmetrazine Phentermine Phenylpropanolamine Pseudoephedrine Rpt Limit 10 ng/ml 10 ng/ml Acode 8062B Postmortem Toxicology Expanded w/o Alcohol, Blood (Forensic) Hospital Blood Analysis by Enzyme Linked Immunosorbent Assay (ELISA) for: Compound Barbiturates Rpt Limit ng/ml Compound Cannabinoids Rpt Limit 10 ng/ml 13 Drug levels and cause of death: a link? Simple, right? Compare levels to a table and voila! Therapeutic vs. toxic vs. lethal levels 14 7

8 Interpreting toxicology lab reports Minimum threshold Therapeutic versus toxic ranges 15 Pitfalls when interpreting drug levels postmortem Site of sampling Time of sampling PMR Referring to lists of lethal concentrations Trauma 16 8

9 Details needed to assess postmortem case Medical/ drug history Autopsy Death scene evidence Tox/lab reports 17 Heroin postmortem 18 9

10 Fentanyl postmortem 19 Ethanol postmortem 20 10

11 Case example (1) Patient prescribed fentanyl patch for pain Opioid naïve patient No patches found on body at autopsy Levels of fentanyl postmortem deemed to be in lethal range Cause of death related to this prescription opioid pain patch? 21 Case example (2) Woman found dead following an auto accident Was in car underwater for several days before being found History of drug abuse. In addiction treatment Heroin metabolites found postmortem Syringes found in car Was she high at the time of the accident? 22 11

12 Case example (3) Man was sold heroin at 7 pm Found dead in his home at 12 midnight Toxicology findings: heroin metabolites, diazepam, methamphetamine Was the death due to the drug he was sold at 7 pm? 23 Case example(4) Man has a negative ( ) postmortem toxicology screen for opiates but has a history of oxycodone use for chronic pain 24 12

13 Allison A. Muller, PharmD, Diplomate American Board of Applied Toxicology (215)