Zolpidem and driving impairment

Zolpidem, a non-benzodiazepine hypnotic, was identified in the blood of 29 subjects arrested for impaired driving. Zolpidem concentrations ranged from 0.05 to 1.4 mg/L (mean 0.29 mg/L, median 0.19 mg/L). In the subjects whose cases we reviewed where zolpidem was present with other drugs and/or alcohol, symptoms reported were generally those of CNS depression. Symptoms included slow movements and reactions, slow and slurred speech, poor coordination, lack of balance, flaccid muscle tone, and horizontal and vertical gaze nystagmus. In five separate cases, where zolpidem was the only drug detected (0.08-1.40 mg/L, mean 0.65 mg/L, median 0.47 mg/L), signs of impairment included slow and slurred speech, slow reflexes, disorientation, lack of balance and coordination, and "blacking out." Although no quantitative relationship between blood concentrations and degree of driving impairment is currently possible, it is reasonable to conclude that because of its specific activity as a sleep inducer, blood concentrations consistent with therapeutic doses of zolpidem have the potential to affect driving in a negative way, and that concentrations above the normal therapeutic range would further impair a person's level of consciousness and driving ability.     

Post-mortem cases involving amphetamine-based drugs in The Netherlands. Comparison with driving under the influence cases

In this study we reviewed the post-mortem cases in the years 1999-2004 that were presented at the Netherlands Forensic Institute. The concentrations of amphetamine-based drugs in femoral blood from cases of suspected unnatural death were compared with concentrations in whole blood from non-fatal cases of driving under the influence (DUI cases) and with literature. Furthermore, the combinations with other drugs and/or alcohol were investigated. Amphetamine-based drugs were present in 70 post-mortem cases and 467 DUI cases. The most detected amphetamine-based drug was MDMA, followed by amphetamine. The presence of MDA could usually be explained by metabolism of MDMA. Methamphetamine and MDEA were rarely present. Frequently, the amphetamine-based drugs were taken in combination with alcohol and/or other non-amphetamine-based drugs such as cocaine or cannabinoids. The 70 post-mortem cases were divided into 38 amphetamine-based drug caused (i.e. the amphetamine-based drug directly caused or contributed to the death) and 32 amphetamine-based drug related deaths (i.e. death was not directly caused by the amphetamine-based drug). In the latter category, other (poly)drug intoxications and death by violence or drowning were the most frequent causes of death. In 30 cases, MDMA caused death directly. The range in blood concentrations of MDMA in these cases was substantial, i.e. 0.41-84 mg/L with a median concentration of 3.7 mg/L (n=30). MDMA blood concentrations in the MDMA related deaths (n=20) and in the DUI cases (n=360) varied up to 3.7 and 4.0 mg/L, respectively. Seven victims died from the direct effects of amphetamine; the blood concentration of amphetamine ranged from 0.24 to 11.3 mg/L, with a median concentration of 1.7 mg/L (n=7). The median concentrations of amphetamine in the amphetamine related deaths (n=13) and the DUI cases (n=208) were much lower, i.e. 0.28 and 0.22 mg/L, respectively. Amphetamine blood concentrations up to 6.0 and 2.3 mg/L were seen in the drug related deaths and DUI cases, respectively. The most frequently encountered amphetamine-based drugs in the investigated deaths were MDMA and amphetamine. The majority of MDMA- and amphetamine-caused deaths, i.e. 90% of these deaths, occurred with blood concentrations above 1.5 and 0.80 mg/L, respectively. MDMA and amphetamine blood concentrations in drug related deaths and DUI cases, however, overlap the range of fatal concentrations. Therefore, MDMA or amphetamine concentrations should never be used alone to establish the cause of death.     

Carisoprodol, meprobamate, and driving impairment

This paper considers the pharmacology of the centrally acting muscle relaxant carisoprodol, and its metabolite meprobamate, which is also administered as an anxiolytic in its own right. Literature implicating these drugs in impaired driving is also reviewed. A series of 104 incidents in which these drugs were detected in the blood of drivers involved in accidents or arrested for impaired driving was considered, with respect to the analytical toxicology results, patterns of drug use in these subjects, the driving behaviors exhibited, and the symptoms observed in the drivers. Symptomatology and driving impairment were consistent with other CNS depressants, most notably alcohol. Reported driving behaviors included erratic lane travel, weaving, driving slowly, swerving, stopping in traffic, and hitting parked cars and other stationary objects. Drivers on contact by the police displayed poor balance and coordination, horizontal gaze nystagmus, bloodshot eyes, unsteadiness, slurred speech, slow responses, tendency to doze off or fall asleep, difficulty standing, walking or exiting their vehicles, and disorientation. Many of these cases had alcohol or other centrally acting drugs present also, making difficult the attribution of the documented impairment specifically to carisoprodol and meprobamate. In 21 cases, however, no other drugs were detected, and similar symptoms were present. Impairment appeared to be possible at any concentration of these two drugs; however, the most severe driving impairment and most overt symptoms of intoxication were noted when the combined concentration exceeded 10 mg/L, a level still within the normal therapeutic range.     

Post-mortem cases involving amphetamine-based drugs in the Netherlands: Comparison with driving under the influence cases

In this study we reviewed the post-mortem cases in the years 1999–2004 that were presented at the Netherlands Forensic Institute. The concentrations of amphetamine-based drugs in femoral blood from cases of suspected unnatural death were compared with concentrations in whole blood from non-fatal cases of driving under the influence (DUI cases) and with literature. Furthermore, the combinations with other drugs and/or alcohol were investigated. Amphetamine-based drugs were present in 70 post-mortem cases and 467 DUI cases. The most detected amphetamine-based drug was MDMA, followed by amphetamine. The presence of MDA could usually be explained by metabolism of MDMA. Methamphetamine and MDEA were rarely present. Frequently, the amphetamine-based drugs were taken in combination with alcohol and/or other non-amphetamine-based drugs such as cocaine or cannabinoids. The 70 post-mortem cases were divided into 38 amphetamine-based drug caused (i.e. the amphetamine-based drug directly caused or contributed to the death) and 32 amphetamine-based drug related deaths (i.e. death was not directly caused by the amphetamine-based drug). In the latter category, other (poly)drug intoxications and death by violence or drowning were the most frequent causes of death.In 30 cases, MDMA caused death directly. The range in blood concentrations of MDMA in these cases was substantial, i.e. 0.41–84 mg/L with a median concentration of 3.7 mg/L (n = 30). MDMA blood concentrations in the MDMA related deaths (n = 20) and in the DUI cases (n = 360) varied up to 3.7 and 4.0 mg/L, respectively. Seven victims died from the direct effects of amphetamine; the blood concentration of amphetamine ranged from 0.24 to 11.3 mg/L, with a median concentration of 1.7 mg/L (n = 7). The median concentrations of amphetamine in the amphetamine related deaths (n = 13) and the DUI cases (n = 208) were much lower, i.e. 0.28 and 0.22 mg/L, respectively. Amphetamine blood concentrations up to 6.0 and 2.3 mg/L were seen in the drug related deaths and DUI cases, respectively. The most frequently encountered amphetamine-based drugs in the investigated deaths were MDMA and amphetamine. The majority of MDMA- and amphetamine-caused deaths, i.e. 90% of these deaths, occurred with blood concentrations above 1.5 and 0.80 mg/L, respectively. MDMA and amphetamine blood concentrations in drug related deaths and DUI cases, however, overlap the range of fatal concentrations. Therefore, MDMA or amphetamine concentrations should never be used alone to establish the cause of death.     

Postmortem forensic toxicology of trazodone

Trazodone is a popular antidepressant medication that has been available for approximately 30 years. It has a reputation as a safe drug with relatively few reported fatalities attributed solely to it. We review the pharmacology and forensic toxicology of trazodone and report toxicology and cause and manner of death in a series of 37 deaths in which trazodone was detected. Although the normal upper therapeutic blood concentration for trazodone is about 2 mg/L, fatalities are rarely attributed solely to it at blood concentrations below 9 mg/L. Considering the pharmacology of the drug, potential interactions between other drugs with serotonin reuptake properties need to be considered, as does the increased susceptibility to the toxic effects in patients with pre-existing heart disease. In the cases reviewed, none were attributed solely to trazodone, although trazodone was frequently present together with other serotonergic drugs, such as the selective serotonin reuptake inhibitors like fluoxetine and sertraline. Ten cases had blood trazodone concentrations above 2 mg/L. Of these cases, trazodone played a primary role in the death of three subjects, with blood concentrations all greater than 9 mg/L. We confirm the conclusions of others that trazodone is a relatively safe drug except in massive overdose, although its toxicity may be influenced by the presence of other drugs and underlying pathophysiology.     

Fatal unintentional intoxications with tramadol during 1995-2005

Tramadol is an extensively used centrally acting analgesic and is considered a safe drug devoid of many serious adverse effects of traditional opioids. However, recently, toxicity and an abuse potential of tramadol have been reported. This study examined fatal unintentional tramadol intoxications among Swedish forensic autopsy cases between 1995 and 2005. All fatal intoxications were selected, in which toxic concentrations of tramadol (>1 microg/g femoral blood) had been detected, and where the forensic pathologist considered the intoxication unintentional and the fatal outcome at least partly explained by tramadol. Toxicology analyses, police reports, autopsy protocols and medical records were scrutinized. A total of 17 cases (eleven men and six women) of fatal unintentional tramadol intoxications were identified. For these cases the median age was 44 years (range 18-78 years) and the median tramadol concentration was 2.0 microg/g (range 1.1-12.0 microg/g). Other pharmaceutical substances, illicit drugs or ethanol were detected in addition to tramadol in all of these cases. In fact, intoxication with multiple drugs was considered the cause of death in 10 (59%) cases. However, in seven cases tramadol was the only substance present in toxic concentrations. A history of substance abuse was identified in 14 (82%) subjects and a present tramadol abuse in 8 (47%). These results suggest that fatal intoxications with tramadol may occur unintentionally and that subjects with a history of substance abuse may be at certain risk. Precaution is therefore warranted when prescribing tramadol in such patients.     

Changing patterns of drug and alcohol use in fatally injured drivers in Washington State

We have previously reported on patterns of drug and alcohol use in fatally injured drivers in Washington State. Here we revisit that population to examine how drug use patterns have changed in the intervening 9 years. Blood and serum specimens from drivers who died within 4 h of a traffic accident between February 1, 2001, and January 31, 2002, were analyzed for illicit and therapeutic drugs and alcohol. Drugs when present were quantitated. Samples suitable for testing were obtained from 370 fatally injured drivers. Alcohol was detected above 0.01 g/100 mL in 41% of cases. The mean alcohol concentration for those cases was 0.17 g/100 mL (range 0.02-0.39 g/100 mL). Central nervous system (CNS) active drugs were detected in 144 (39%) cases. CNS depressants including carisoprodol, diazepam, hydrocodone, diphenhydramine, amitriptyline, and others were detected in 52 cases (14.1%), cannabinoids were detected in 47 cases (12.7%), CNS stimulants (cocaine and amphetamines) were detected in 36 cases (9.7%), and narcotic analgesics (excluding morphine which is often administered iatrogenically in trauma cases) were detected in 12 cases (3.2%). For those cases which tested positive for alcohol c. 40% had other drugs present which have the potential to cause or contribute to the driver's impairment. Our report also considers the blood drug concentrations in the context of their interpretability with respect to driving impairment. The data reveal that over the past decade, while alcohol use has declined, some drug use, notably methamphetamine, has increased significantly (from 1.89% to 4.86% of fatally injured drivers) between 1992 and 2002. Combined drug and alcohol use is a very significant pattern in this population and is probably overlooked in DUI enforcement programs.     

Determining the Toxicological Significance of Pregabalin in Fatalities

Pregabalin has become more widely prescribed and abused in recent years but is still not always included in laboratory analysis. An LC‐MS‐MS method has been developed and applied to measure pregabalin in 93 postmortem cases, including drug‐related deaths, alternative causes of death, and fatalities where pregabalin was likely to have contributed to death. Other drugs or alcohol was detected, and the most common drug types (in decreasing frequency) were antidepressants, opioids, benzodiazepines, opiates, alcohol, antipsychotics, cocaine, cardiac drugs, amphetamines, cannabis, anticonvulsants, and antihistamines. New psychoactive substances (methoxphenidine and synthetic cannabinoids) were only found in two cases. The results provide further data to assist in evaluating the significance of postmortem pregabalin concentrations and a toxicologically significant concentration of 25 mg/L is proposed. Pregabalin, especially with concomitant use of other CNS depressant drugs, presents a significant toxicological risk and existing laboratory protocols should be reviewed for their suitability to detect pregabalin.     

Acetyl Fentanyl: Trends and Concentrations in Metro Detroit

Acetyl fentanyl (N‐[1‐phenethylpiperidin‐4‐yl]‐N‐phenylacetamide) is a potent opioid analgesic with no medicinal uses. We report deaths between 2016 and 2017 at the Medical Examiner's Office in Detroit, MI where acetyl fentanyl was found in the decedent's blood and compare them to previously published deaths between 2015 and 2016. The recent cases (cohort B) had a mean acetyl fentanyl concentration of 0.9 ng/mL (range: 0.1–5.3 ng/mL) and an associated higher concentration of fentanyl along with multiple other drugs present. The older cases (cohort A) had higher concentrations of acetyl fentanyl (mean: 8.9 ng/mL; range: 0.28–37 ng/mL) with lower, yet still toxic, concentrations of fentanyl. We conclude that the cause of death in these recent cases was likely multiple drug toxicity with fentanyl and that the consistently observed lower peripheral blood concentrations of acetyl fentanyl are most likely an artifact in the manufacture of the consumed illicit fentanyl.     

Methadone‐Related Deaths – Epidemiological,Pathohistological, and Toxicological Traits in 10‐year Retrospective Study in Vojvodina,Serbia

The number of methadone‐related deaths (MRDs) during a 10‐year period (2002–2011) in the region of Vojvodina, Serbia, was increased. The cases were evaluated according to epidemiological parameters, pathohistological findings, and toxicological screening. The majority of victims were men, aged from 20 to 38. Pathohistologically, the signs of acute focal myocardial damage were present in the heart of victims with drug abuse history shorter than 2 years, while both signs of recent and chronic focal myocardial damage were developed among victims with longer drug abuse history (2–5 years). In postmortem blood samples of 54.84% of victims, methadone was detected in combination with diazepam, both in therapeutic range. Alcohol was absent in most cases. Other detected drugs were antipsychotics and antidepressants in therapeutic concentrations. These findings raise the attention to the concomitant use of methadone and benzodiazepines with the need for further studies to clarify the mechanism of death in such cases.     

Anaphylaxis After the Injection of Buprenorphine

Cause of death rulings in cases when the concentration of a drug or drugs is higher than observed following therapeutic use are generally straightforward “drug deaths.” However, when toxicology testing identifies drug concentrations consistent with therapeutic use or detects no drugs at all, then the cause of death determination is more complicated. Given the rapidity and protean manifestations of anaphylaxis, it should be considered in deaths where no other cause of death is apparent in a suspected drug death. This article reports two cases where an anaphylactic reaction was observed following either the actual or alleged use of therapeutic formulations of buprenorphine intravenously.     

GHB and driving impairment.

Gamma hydroxybutyrate (GHB) was identified in the blood of 13 subjects arrested for impaired driving. GHB concentrations ranged from 26 to 155 mg/L (mean 87 mg/L, median 95 mg/L). In eight cases, GHB was the only drug detected, and signs of impairment were consistent with those of a CNS depressant, including erratic driving (weaving, swerving, ignoring road signs), confusion, incoherent speech, unresponsiveness, lack of balance, unsteady coordination, poor performances on field sobriety tests, and varying states of wakefulness. Given the ability of GHB to induce sleep and unconsciousness, it is evident from these cases that recreational use of the drug has the potential to impair a person's driving ability.     

Zaleplon and driving impairment

Zaleplon, a sedative-hypnotic, was identified in the blood of a subject arrested for impaired driving. Symptoms reported were those of central nervous system (CNS) depression. The zaleplon concentration was determined to be 0.13 microg/mL. Symptoms included slow movements and reactions, poor coordination, and lack of balance. Although no quantitative relationship between blood concentrations and degree of driving impairment is currently possible, it is reasonable to conclude that because of its specific activity as a sedative-hypnotic, blood concentrations consistent with doses exceeding therapeutic concentrations of zaleplon have the potential to cause impairment of psychomotor function, and would impair a person's level of consciousness and driving ability.     

The prevalence of drugs in carbon monoxide-related deaths: a retrospective study, 2000-2003

The objective of this study was to review demographic characteristics and drugs detected in carbon monoxide (CO)-related deaths from cases received by the Office of the Cuyahoga County Coroner in Cleveland, Ohio, from 2000-2003. Postmortem reports were reviewed, and decedents for which CO was listed as the cause of death were included. The data were compiled into 3 groups according to the official coroner's verdict as to the manner of death: accident, suicide, and homicide. Included in this study were 122 cases: 84 (69%) accidental, 31 (25%) suicide, and 7 (6%) homicide. Accident decedents were typically white males, aged 40-59 years, residing in Cleveland. Suicide decedents were also middle-aged, white males but residing in the suburbs. Homicide decedents under the age of 6 were characteristically black (N=2), while decedents over the age of 39 were predominately white (N=3). Carboxyhemoglobin (COHb) levels in suicide cases were higher than concentrations measured in accidental deaths. The highest percentage of suicide decedents (36%) had a COHb level>70% saturation, accident decedents (36%) between 50% and 69% saturation, and homicide decedents (71%) below 50% saturation. Ethanol (N=34) was detected in 28% of deaths, and therapeutic and/or abused drugs (N=50) were detected in 41% of deaths. Illicit drugs were detected in 11% of cases (cocaine/metabolites; THC/metabolites), other drug positives were therapeutic medications. The most common drugs detected were antidepressants and antihistamines in suicides and pain medications and antihistamines in accidents.     

Tissue distribution of tramadol and metabolites in an overdose fatality

Tramadol (Ultram) is a centrally acting, synthetic analgesic agent. Although it has some affinity for the opiate receptors, tramadol is believed to exert its analgesic effect by inhibiting the re-uptake of norepinephrine and serotonin. There are several published cases of tramadol's involvement in drug-related deaths and impairment. Reports of deaths involving tramadol alone with associated tissue concentrations are rare. This report documents a case in which tramadol overdose was identified as the cause of death. The following tramadol concentrations were found in various tissues: blood, 20 mg/L; urine, 110.2 mg/L; liver, 68.9 mg/kg; and kidney, 37.5 mg/kg. Tissue distributions of the two primary metabolites, N-desmethyl and O-desmethyl tramadol, are also reported. In each tissue or fluid except urine, the tramadol concentration was greater than either metabolite, consistent with other reports of drug-impaired drivers and postmortem cases. The O-desmethyl metabolite concentration was greater than the N-desmethyl metabolite concentration in all tissues; this is in contrast to other postmortem reports, in which the majority of cases report concentrations of O-desmethyl as less than those of N-desmethyl. This may be useful as an indicator of time lapse between ingestion and death.     

Toxicology case data reporting system

A computerized system has been organized to serve the toxicology sections of seven R.C.M.P. laboratories across Canada. Scientists may view and retrieve information concerning drugs and drug combinations, blood and liver drug concentrations, etc. from cases of sudden death or impaired driving which were analyzed in the laboratories. This has proven to be a great help in interpreting toxicology case results for the investigator or the courts and also in choosing methodology to be used in analyzing specimens for unusual drugs or poisons.