Drug Impaired Driving: A Toxicologist Perspective Bruce A. Goldberger, Ph.D. Division of Forensic Medicine Departments of Pathology and Psychiatry University of Florida College of Medicine

Decedent Driver: Blood THC – 62 ng/mL

“A poison in a small dose is a medicine, and a medicine in a large dose is a poison.” Alfred Swaine Taylor (1859)

Legal Definition of Impairment It is unlawful and punishable as provided in Chapter 322 and in S for any person who is under the influence of alcoholic beverages or controlled substances, when affected to the extent that the person’s normal faculties are impaired or to the extent that the person is deprived of full possession of normal faculties, to drive or be in actual physical control of any motor vehicle within this state. Such normal faculties include, but are not limited to, the ability to see, hear, walk, talk, judge distances, drive an automobile, make judgments, act in emergencies, and, in general, normally perform the many mental and physical acts of daily life.

The Role of Alcohol in Traffic Accidents (Grand Rapids Study)

Drug Impaired Driving  More difficult to prosecute than alcohol- impaired driving  Under-reported, under-recognized  Drugs are constant factor in traffic crashes  Full impact unknown Source: DHHS and NHTSA

Which Drugs Can Affect Driving? 1. Any drug that can affect the brain’s perception, collection, processing, storage or critical evaluation processes. 2. Any drug that affects communication of the brain’s commands to muscles or organ systems that execute them. 3. For the most part, drugs that affect the central nervous system.

Psychoactive Substances CNS Depressants CNS Stimulants Other substances

Contemporary Analytes Opioids Buprenorphine Buprenorphine Codeine Codeine Fentanyl Fentanyl Hydrocodone Hydrocodone Hydromorphone Hydromorphone Methadone Methadone Morphine Morphine Oxycodone Oxycodone Oxymorphone Oxymorphone Tapentadol Tapentadol Tramadol Tramadol Benzodiazepines Alprazolam Alprazolam Clonazepam Clonazepam Diazepam Diazepam Lorazepam Lorazepam Temazepam Temazepam

Contemporary Analytes Sedative Hypnotics Butalbital Carisoprodol/Meprobamate Diphenhydramine/Doxylamine Zolpidem

Contemporary Analytes Inhalants Emerging Psychotropic Drugs Synthetic Cannabinoids Synthetic Cannabinoids Substituted Amphetamines Substituted Amphetamines Cathinones Cathinones

Toxidrome Constellation of signs and symptoms associated with the ingestion of a specific poison.

Signs and Symptoms: Depressants  Confusion  Poor divided attention  Sedation  Droopy eyelids  Slowed reaction times  Memory effects  HGN  Poor balance  Poor coordination  Unsteadiness  Slurred speech  Disorientation  Low b.p.  Low pulse

Signs and Symptoms: Stimulants  Hypervigilant  Excitability  Anxious  Self absorbed  Agitated  Paranoid  Delusional  Obsessive activity  Rapid speech  Thought blending  Tremors  Hand wringing  jaw clenching  Dilated pupils  Elevated b.p.  Elevated pulse

Signs and Symptoms: Opiates  Euphoria  Sedation  Confusion  Stupor  Droopy eyelids  Slowed reaction times  Slowed reflexes  Poor balance  Poor coordination  Constricted pupils  Low pulse  Low b.p.

Signs and Symptoms: Marijuana  Relaxed  Sedation  Confused  Poor divided attention  Memory effects  Poor balance  Poor coordination  Reddening of eyes  Eyelid tremors  Elevated pulse  Elevated b.p.

Signs and Symptoms: Stimulant Withdrawal  Hypersomnolence  Fatigue  Exhaustion  Withdrawal  Agitated  Paranoia  Delusions  Tremors  Chills Stimulant withdrawal can mimic depressant effects

Recognition of the Drug-Impaired Driver First Choice: DRE Non-DRE Officer

What is the Basis for the Opinion of Impairment?  Drug effect (pharmacology and toxicology)  Opinion rarely based upon the drug report alone  Must also evaluate the toxicological findings in context of the case

DRE Matrix HGN Vertical nystagmus Lack of convergence Pupil size Reaction to light Pulse rate Blood pressure Body temperature Other indicators

What the Toxicologist cannot do….  Determine impairment in a specific individual from a drug concentration alone  Determine exactly how much drug was taken  Determine exactly when a drug was taken

Drug Interpretation Issues  Individual response  Multiple drug use  Tolerance  History of drug use (chronicity  Health status  Metabolism  Genetic/Ethnic differences

Alcohol. The continued use of per se concentration limits for alcohol is recommended. However, it is time to reevaluate the current limit of 0.08 g/dL. Prescription drugs. A valid prescription constitutes an affirmative defense against a per se standard, although impaired drivers can be prosecuted under the impairment arm of a drugged driving law if they exhibit clinical signs and symptoms of impairment. Without a valid prescription, any potentially impairing medication present in the blood constitutes per se evidence of drugged driving. Alcohol and prescription drugs. Based on available evidence of additive or supra-additive impairing effects of alcohol and other drugs, the alcohol per se concentration should be lowered in these contexts to ≥0.05 g/dL. Illegal/illicit drugs. Any illegal/illicit drug present in the blood of a driver suspected of impairment should constitute per se evidence of drugged driving. Over-the-counter medications. Drivers demonstrating impaired driving behavior should be prosecuted under the impairment arm of the drugged driving law. (JAT, DuPont, Goldberger, Gold and Reisfield, 2012