Sudden death and benzodiazepines

A pharmacovigilance approach for assessing the occurrence of suicide-related events induced by antiepileptic drugs using the Japanese adverse drug event report database

Increased suicidality after antiepileptic drug (AED) treatment remains controversial. This study aimed to investigate the occurrence of suicide-related events (SREs) in Japan. SREs signals with AEDs used orally were evaluated by calculating reporting odds ratios (RORs) and information components (ICs) using the Japanese Adverse Drug Event Report (JADER) database from April 2004 to December 2021. Additionally, factors affecting the occurrence of SREs and time-to-onset from the initial AED treatment were analyzed. Of 22 AEDs, 12 (perampanel hydrate, nitrazepam, levetiracetam, clonazepam, clobazam, sodium valproate, phenobarbital, lamotrigine, lacosamide, gabapentin, zonisamide, and carbamazepine) showed signals of SREs. Patients in their 20 and 30 s, female sex, and concomitant use of multiple AEDs affected the occurrence of SREs. In six AEDs, the median time-to-onset of SREs in patients taking all AEDs was <100 days. The pharmacovigilance approach revealed that several AEDs displayed suicidality signals. Female patients, those in their 20 and 30 s, undergoing combination therapy with ≥2 AEDs, and patients early (<100 days from the initial treatment) in the course of AED therapy should be cautioned about SREs.

Superparamagnetic Fe3 O4 @SiO2 core-shell composite nanoparticles for the mixed hemimicelle solid-phase extraction of benzodiazepines from hair and wastewater samples before high-performance liquid chromatography analysis

Magnetic Fe3 O4 /SiO2 composite core-shell nanoparticles were synthesized, characterized, and applied for the surfactant-assisted solid-phase extraction of five benzodiazepines diazepam, oxazepam, clonazepam, alprazolam, and midazolam, from human hair and wastewater samples before high-performance liquid chromatography with diode array detection. The nanocomposite was synthesized in two steps. First, Fe3 O4 nanoparticles were prepared by the chemical co-precipitation method of Fe(III) and Fe(II) as reaction substrates and NH3 /H2 O as precipitant. Second, the surface of Fe3 O4 nanoparticles was modified with shell silica by Stober method using tetraethylorthosilicate. The Fe3 O4 /SiO2 composite were characterized by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. To enhance their adsorptive tendency toward benzodiazepines, cetyltrimethylammonium bromide was added, which was adsorbed on the surface of the Fe3 O4 /SiO2 nanoparticles and formed mixed hemimicelles. The main parameters affecting the efficiency of the method were thoroughly investigated. Under optimum conditions, the calibration curves were linear in the range of 0.10-15 μgmL(-1) . The relative standard deviations ranged from 2.73 to 7.07%. The correlation coefficients varied from 0.9930 to 0.9996.

The Large Role of Prescription Drugs in Accidental Drug Deaths

Drug abuse may involve illicit drugs, prescription drugs, or the combination of illicit and prescription drugs, with or without the use of alcohol. Historically, illicit drugs have been responsible for many of the drug-related deaths investigated by medical examiner and coroner offices. However, in more recent years, deaths resulting from prescription drugs have become increasingly more common. This study reviewed all accidental (unintentional) drug deaths that were investigated at a medical examiner's office over a one-year time frame. The study revealed that prescription drugs made up the largest category of drug deaths, followed by prescription drug/illicit drug combinations, followed by illicit drugs. Drugs capable of causing or contributing to significant respiratory insufficiency such as opioids, benzodiazepines, relaxants (defined as muscle relaxants or sleep medications), and alcohol, or some combination thereof, were detected in 197 out of 256 (77%) of all accidental drug deaths, and were detected in 132 out of 138 (95%) of all prescription drug deaths (cases without any illicit drugs detected). These prescription drugs were most often found in combination, and their similar respiratory depressant effects can be cumulative and deadly.

Reactivity of commercial benzodiazepine immunoassays to phenazepam

Phenazepam is a long acting benzodiazepine that is not controlled in Canada, the United States or many European countries. The abuse of phenazepam has gained recent attention due to the number of hospitalizations and fatalities resulting from overdose. The compound is relatively potent with recommended doses of 0.5-1.0 mg, or 1/10th the recommended dose of diazepam, and is easy to obtain locally or from international suppliers via the internet. Increased risk of phenazepam overdose is attributed to its potency and the forms in which it is supplied. Individuals without scales or balances are prone to estimate dose amounts of powder visually, which can result in significant errors. The detection of phenazepam has been described using various methods including GC, GC/MS and LC/MS, but no data regarding the sensitivity of commercially available immunoassays exist. In this study, phenazepam-spiked urine samples were analyzed using five commercial instruments and two point of care devices. The concentrations of phenazepam required for detection ranged from 140-462 ng/mL, which is comparable to those of other benzodiazepines. Laboratorians and clinicians should be confident that phenazepam will be detected via most commercial drugs of abuse screens in patients after significant ingestion.

A fast liquid chromatography-tandem mass spectrometry method for determining benzodiazepines and analogues in urine. Validation and application to real cases of forensic interest

A fast liquid chromatographic/tandem mass spectrometric method was developed for the simultaneous determination in human urine of seventeen benzodiazepines, four relevant metabolites together plus zolpidem and zopiclone. The sample preparation, optimized to take into account the matrix effect, was based on enzymatic hydrolysis and liquid-liquid extraction. The separation of the twenty-three analytes was achieved in less than eight minutes. The whole methodology was fully validated according to UNI EN ISO/IEC 17025:2005 rules and 2006 SOFT/AAFS guidelines. Selectivity, linearity range, identification (LOD) and quantitation (LOQ) limits, precision, accuracy and recovery were evaluated. For all the species the signal/concentration linearity was satisfactory in the 50-1000 ng/mL concentration range. The limits of detection ranged from 0.5 to 30 ng/mL and LOQs from 1.7 to 100.0 ng/mL. Precisions were in the ranges 5.0-11.8%, 1.5-11.0% and 1.1-4.4% for low (100 ng/mL), medium (300 ng/mL) and high (1000 ng/mL) concentration, respectively. The accuracy, expressed as bias% was within ± 25 % for all the analytes. The recovery values, evaluated at 300 ng/mL concentration, ranged from 56.2% to 98.8%. The present method for the determination of several benzodiazepines, zolpidem and zopiclone in human urine proved to be simple, fast, specific and sensitive. The quantification by LC-MS/MS was successfully applied to 329 forensic cases among driving re-licensing, car accidents and alleged sexual violence cases.

Benzodiazepines: sample preparation and HPLC methods for their determination in biological samples

Benzodiazepines (BDZs) belong to a group of substances known for their sedative, antidepressive, muscle relaxant, tranquilizer, hypnotic and anticonvulsant properties. Their determination in biological fluids is essential in clinical assays as well as in forensics and toxicological studies. Researchers focus on the development of rapid, accurate, precise and sensitive methods for the determination of BDZs and their metabolites. A large number of analytical methods using different techniques have been reported, but none can be considered as the method of choice. BDZs are usually present at trace levels (microgram or nanogram per milliliter) in a complex biological matrix and the potentially interfering compounds must be isolated by various extraction techniques before analysis. An extended and comprehensive review is presented herein, focusing on sample preparation (pretreatment and extraction) and HPLC conditions applied by different authors. These methods enable bioanalysts to achieve detection limits down to 1-2 ng/ml using UV/diode array detection, readily available in most laboratories, and better than 1 ng/ml using electron capture detection, which is lower than that obtained using a nitrogen phosphorus detector. MS interfaced with electrospray ionization offered a similar sensitivity, while negative chemical ionization MS or sonic spray ionization MS provided sensitivity down to 0.1 ng/ml.

Deaths in the first two weeks of maintenance treatment in NSW in 1994: identifying cases of iatrogenic methadone toxicity

A study was undertaken to estimate the frequency of iatrogenic methadone toxicity in the first 2 weeks of maintenance treatment in NSW. Cases were identified from a list of all 1994 methadone-associated deaths using data on methadone patients held by the NSW and Queensland Health Departments. The likely causes of death were determined from data collected from coronial files. A forensic toxicologist experienced in the area gave an independent opinion. Of the 14 deaths in the first 2 weeks of maintenance, at least 10 were primarily caused by the toxic effects of methadone prescribed by NSW doctors. The rate of fatal iatrogenic methadone toxicity was 2.2 per thousand admissions to maintenance. Victims of fatal iatrogenic toxicity often displayed signs of methadone intoxication in the days before their death. They invariably died several hours after taking the fatal dose, usually after seeming to go to sleep. Often friends or family were concerned about their welfare, were unable to rouse them from their "sleep" and frequently reported the deceased was "snoring" loudly for some time before their demise. The author recommends that patients entering methadone maintenance should be informed of the risks and should be required to give written consent to treatment. To prevent fatal methadone toxicity, patients should receive daily medical assessment during the first 1-2 weeks of maintenance.

Does age matter? Comparing case fatality rates for selected poisonings reported to U.S. poison centers

BACKGROUND

As the elderly population continues to grow, the number of geriatric patients reported to poison centers continues to increase. We believe that older poisoned patients are at an increased risk of death compared to younger adult patients. The objective of this study was to compare the risk of death from selected poisoning between younger (<59) and older (>59) adults.

METHODS

We included adult cases reported to U.S. poison centers between 1995 and 2002. To limit potential confounders, our analysis included single substance ingestions of theophylline, digoxin, benzodiazepines, tricyclic antidepressants, calcium channel antagonists, acetaminophen, and salicylate. We determined the case fatality rate for each poisoning for younger and older adults. We calculated crude odds ratios for each poison and then used logistic regression to adjust for covariates.

RESULTS

Overall we found an increase in the relative rate of death for each poison (range 1.2 to 7.1). After adjustment, each 10-year increase in age was associated with a 36% increase in the odds ratio for death as an outcome. Our findings were limited by the use of poison center data, which does not include data on covariates that may be potential confounders.

Liquid chromatography–electrospray ionisation mass spectrometry for the determination of nine selected benzodiazepines in human plasma and oral fluid

A new simple and rapid liquid chromatographic-mass spectrometric technique was designed for the determination of nine benzodiazepines in plasma and oral fluid. Benzodiazepines were extracted from alkalinised spiked and clinical plasma and oral fluid samples using a single step, liquid-liquid extraction procedure with diethyl ether. The chromatographic separation was performed with a Xterra RP18, 5 microm (150 x 2.1 mm i.d.) reversed-phase column using deuterated analogues of the analytes as internal standard. The recovery ranged from 70.3 to 86.9% for plasma and 63.9 to 77.2% for oral fluid. The limits of detection ranged from 0.5 to 1 ng/ml in plasma and 0.1 to 0.2 ng/ml for oral fluid. The method was validated for all the compounds, including linearity and the main precision parameters. The procedure, showed to be sensitive and specific, was applied to real plasma and oral fluid samples. The method is especially useful to analyse saliva samples from drivers undergoing roadside drug controls.

Forensic intoxication with clobazam: HPLC/DAD/MSD analysis

Clobazam (Castillium, Urbanil), a benzodiazepine often used as an anxiolytic and in the treatment of epilepsy, is considered a relatively safe drug. The authors present a fatal case with a 49-year-old female, found dead at home. She had been undergoing psychiatric treatment and was a chronic alcoholic. The autopsy findings were unremarkable, except for multivisceral congestion, steatosis and a small piece of a plastic blister pack in the stomach. Bronchopneumonia, bronchitis and bronchiolitis were also diagnosed. Anhigh-performance liquid chromatography (HPLC)/diode array detector (DAD)/mass spectrometry detection (MSD) with electrospray method was developed in order to detect, confirm and quantify clobazam in the post-mortem samples. In the chromatographic separation, a reversed-phase column C18 (2.1 x 150 mm, 3.5 microm) was used with a mobile phase of methanol and water, at a 0.25 ml/min flow rate. Carbonate buffer (pH 10.5) and 20 microl of prazepam (100 microg/ml) as internal standard were added to the samples. A simple and reliable liquid-liquid extraction method for the determination of clobazam in post-mortem samples was described. Calibration curves for clobazam were performed in blood, achieving linearity between 0.01 and 10 microg/ml and a detection limit of 1.0 ng/ml. The clobazam concentration found in post-mortem blood was 3.9 microg/ml, higher than the reported therapeutic concentration (0.1-0.4 microg/ml). The simultaneous acquisition by photodiode array detection and mass spectrometry detection results allowed benzodiazepines to be identified with sufficient certainty. An examination of all the available information suggested that death resulted from respiratory depression due to clobazam toxicity.

Alprazolam is relatively more toxic than other benzodiazepines in overdose

AIMS

To describe alprazolam poisoning and the relative toxicity of alprazolam compared with other benzodiazepines.

METHODS

A database of consecutive poisoning admissions to a regional toxicology service was searched to identify consecutive benzodiazepine deliberate self poisonings, which were coded as alprazolam, diazepam or other benzodiazepine. Major outcomes used were length of stay (LOS), intensive care (ICU) admission, coma (GCS < 9), flumazenil administration and requirement for mechanical ventilation. Prescription data were obtained for benzodiazepines for the study period.

RESULTS

There were 2063 single benzodiazepine overdose admissions: 131 alprazolam overdoses, 823 diazepam overdoses and 1109 other benzodiazepine overdoses. The median LOS for alprazolam overdoses was 19 h which was 1.27 (95% CI 1.04, 1.54) times longer compared with other benzodiazepines by multiple linear regression. For patients with alprazolam overdoses, 22% were admitted to ICU which was 2.06 (95% CI 1.27, 3.33) times more likely compared with other benzodiazepines after multivariate analysis adjusting for age, dose, gender, time to ingestion and co-ingested drugs. Flumazenil was administered to 14% of alprazolam patients and 16% were ventilated, which was significantly more than for other benzodiazepine overdoses (8% and 11%, respectively). Twelve percent of alprazolam overdoses had a GCS < 9 compared with 10% for other benzodiazepines. From benzodiazepine prescription data, total alprazolam prescriptions in Australia increased from 0.13 million in 1992 to 0.41 million in 2001. Eighty five percent of prescriptions were for panic disorder, anxiety, depression or mixed anxiety/depression.

CONCLUSIONS

Alprazolam was significantly more toxic than other benzodiazepines. The increased prescription of alprazolam to groups with an increased risk of deliberate self poisoning is concerning and needs review.

Effects of high-dose intravenous buprenorphine in experienced opioid abusers

Sublingual buprenorphine, a long-acting, partial mu-opioid agonist, is as effective as methadone in the treatment of heroin dependence, with a better safety profile due to its antagonist activity. However, the safety of therapeutic doses (8 to 16 mg) that might be diverted for intravenous (i.v.) use has not been demonstrated. To evaluate the safety and possible ceiling effects of buprenorphine administered i.v. to experienced opioid users, buprenorphine was administered to 6 nondependent opioid abusers residing on a research unit; the doses tested, in separate sessions, were 12 mg buprenorphine sublingual, i.v./sublingual placebo, and escalating i.v. buprenorphine (2, 4, 8, 12, and 16 mg). Physiologic and subjective measures were collected for 72 hours post-drug administration. Buprenorphine minimally but significantly increased systolic blood pressure. Changes in heart rate or oxygen saturation among the 7 drug conditions were not statistically significant. The mean maximum decrease in oxygen saturation from baseline was greatest for the 8-mg i.v. dose. Buprenorphine produced positive mood effects, although with substantial variability among participants. Onset and peak effects occurred earlier following i.v. administration: peak i.v. effects occurred between 0.25 and 3 hours; peak sublingual effects occurred at 3 to 7 hours. Duration of effects varied among the outcome measures. The dose-response curves were flat for most parameters, particularly subjective measures. Side effects were mild except in one participant who experienced severe nausea and vomiting after the 12-mg i.v. dose. Buprenorphine appears to have a ceiling for cardiorespiratory and subjective effects and a high safety margin even when taken by the i.v. route.

Acute toxic effects of club drugs

This article summarizes the short-term physiological toxicity and the adverse behavioral effects of four substances (GHB, ketamine, MDMA, and Rohypnol) that have been used at latenight dance clubs. The two primary data sources were case studies of human fatalities and experimental studies with laboratory animals. A safety ratio was calculated for each substance based on its estimated lethal dose and its customary recreational dose. GHB (gamma-hydroxybutyrate) appears to be the most physiologically toxic; Rohypnol (flunitrazepam) appears to be the least physiologically toxic. The single most risk-producing behavior of club drug users is combining psychoactive substances, usually involving alcohol. Hazardous drug-use sequelae such as accidents, aggressive behavior, and addiction were not factored into the safety ratio estimates.

The role of benzodiazepines in elderly suicides

AIMS

In Sweden, suicides by drug poisoning have decreased in the population at large during the past two decades. However, drug poisoning suicides increased among the elderly during this period. Suicides by benzodiazepine poisoning increased in this age group despite a reduction in prescription sales of these drugs. This study aims therefore to determine the role of benzodiazepines in suicide late in life.

METHODS

Information concerning all definite suicides and deaths due to "undetermined" causes recorded among Swedish citizens aged 65 and above during 1992 - 96 was obtained from the Cause-of-Death Register. Death certificates were scrutinized to determine the type of drug employed in drug-related suicides. Results of the post mortem screening for drugs and alcohol were then examined.

RESULTS

A benzodiazepine was implicated in 216/548 (39%) of the drug poisoning suicides recorded among the elderly. Death certificates revealed that a benzodiazepine was the sole agent in 72% of these cases. Flunitrazepam or nitrazepam were implicated in 90% of the single benzodiazepine suicides. In addition to the suicides classified as drug poisonings, 82 cases were found in which a drug may have contributed to the cause of death. Benzodiazepines predominated. The terminal cause of death was drowning, often in the victim's own bathtub, in three-quarters of these cases. The annual fatality ratios for the newer benzodiazepine-like hypnotics zopiclone and zolpidem appear to be on the rise.

CONCLUSION

Benzodiazepines, especially the hypnotics flunitrazepam and nitrazepam, are common in drug poisoning suicides in the elderly and should be prescribed with caution for this age group.

Tissue distribution of nitrazepam and 7-aminonitrazepam in a case of nitrazepam intoxication

We report a case of nitrazepam poisoning in which the distribution of nitrazepam and 7-aminonitrazepam was determined in body fluids and tissues. A 52-year-old woman was found dead in a shallow ditch (approximately 5 cm in depth), in the winter. Ambient temperature was 2-8 degrees C. The postmortem interval was estimated to be approximately 1 day and no putrefaction was observed. The cause of death was thought to be drowning due to nitrazepam overdose and cold exposure. Blood concentrations of nitrazepam and 7-aminonitrazepam were very site dependent (0.400-0.973 microg/ml and 0.418-1.82 microg/ml). In addition, the concentration of the same analytes in the bile were 4.08 and 1.67 microg/ml, respectively, and in the urine: 0.580 and 1.09 microg/ml, respectively. A high accumulation of both substances was observed in various types of brain tissue (2.17-6.22 microg/g and 2.49-5.11 microg/g). Only small amounts of nitrazepam and 7-aminonitrazepam were detected in the liver (0.059 and 0.113 microg/g, respectively). Large differences in the observed concentrations of nitrazepam and 7-aminonitrazepam among arterial and venous blood samples were thought to be mainly due to dilution of arterial blood by water entering the circulation through lungs at the time of death. Bacterial metabolism of nitrazepam may also have contributed to the observed differences.

Fatal methadone toxicity: signs and circumstances, and the role of benzodiazepines

OBJECTIVE

To describe the signs and symptoms and circumstances of fatal methadone toxicity and investigate the role of benzodiazepines in these deaths.

METHODS

Data were extracted from 1994 New South Wales (NSW) coronial files and cause of death established independently. Cases were grouped according to the likely source of methadone. Data describing the clinical history and circumstances of death were extracted from witnesses' and police statements.

RESULTS

Methadone contributed to the deaths of 57 of the 87 adult coronial cases in which it was detected in NSW in 1994. The most commonly reported early signs of severe methadone toxicity were ataxia, slurred speech and evident euphoria. The late signs were unconsciousness, loud snoring and brown pulmonary oedema fluid coming from the mouth or nose. Death occurred an average 5.1 and 6.0 hours after oral ingestion and intravenous injection of methadone, respectively. Benzodiazepines were significantly more likely to have contributed to deaths from methadone toxicity among maintenance patients and people taking methadone tablets for pain relief than deaths involving diverted methadone syrup and deaths to which methadone did not contribute (OR 4.8, 95% 1.7 to 14.4).

CONCLUSIONS AND IMPLICATIONS

Benzodiazepines may contribute to deaths from methadone toxicity by increasing upper airways obstruction. Victims would have had a greater chance of survival if they had either been placed in the coma position or given mouth-to-mouth ventilation and an ambulance had been called. Benzodiazepines are more likely to contribute to fatal methadone toxicity in newly admitted maintenance patients and those taking methadone tablets for pain relief.

Determination of delorazepam in urine by solid-phase microextraction coupled to high performance liquid chromatography

An SPME-HPLC-UV method for the determination of delorazepam, a representative benzodiazepine, in spiked human urine samples was developed for the first time. The performances of two commercially available fibers, a carbowax/templated resin (Carbowax/TPR-100) and a polydimethylsiloxane/divinylbenzene (PDMS/DVB), were compared, indicating the latter as the most suitable for urine samples analysis. All the aspects influencing adsorption (extraction time, pH, temperature, salt addition) and desorption (desorption and injection time, desorption solvent mixture composition) of the analyte on the fiber have been investigated. In particular, short extraction times were necessary to reach the equilibrium and very short desorption times were employed. The procedure required simple sample pre-treatment and was able to detect 5 ng/ml in spiked urine, regardless of the complexity of the matrix.

Toxicological interactions between alcohol and benzodiazepines

BACKGROUND

We review recentfindings on the toxicological interactions between alcohol (ethanol) and benzodiazepines, and the combined use of benzodiazepines and alcohol in fatal poisoning. Acute ingestion of alcohol combined with benzodiazepines is responsible for several toxicological interactions that can have significant clinical implications. In general, metabolism of these drugs is delayed when combined with acute alcohol ingestion although some reports suggest otherwise. Alternately, the drugs metabolized during chronic alcohol ingestion have an increased clearance. The net effect may also be influenced by internal (e.g., disease, age) and external (e.g., environment, diet) factors. Fatal poisoning involving coadministration of alcohol and benzodiazepine, especially triazolam, continues to be a serious problem.

Hypothermia and undressing associated with non-fatal bromazepam intoxication

A 42-year-old woman with a history of depression was found unconscious, lying near her car in an early autumn morning. The lower part of her body was undressed and there were multiple purple spots and excoriations on the body suggesting at first a sexual assault. On admission to the intensive care unit, she presented a hypothermia with a central temperature of 28.4 degrees C. The biological samples obtained at the hospital were analysed. Blood concentration of bromazepam was 7.7 mg/l, which is above the highest level reported till now in a case of fatal intoxication.

Direct LC analysis of five benzodiazepines in human urine and plasma using an ADS restricted access extraction column

An alkyl-diol-silica (ADS) precolumn was used for the direct and on-line extraction of several benzodiazepines from serum and urine. The protein component of the biological sample was flushed through the ADS column, while simultaneously extracting the benzodiazepine compounds in the pores of the ADS stationary phase. The role of hydrophobic interactions in the extraction mechanism was confirmed. Column switching was employed to elute the extracted analytes from the ADS column into a high-performance liquid chromatography reverse-phase C18 column for the isocratic separation and UV detection of the benzodiazepines. Sample preconcentration via large volume injections was possible, improving the limits of detection. The calculated clonazepam, oxazepam, temazepam, nordazepam and diazepam detection limits were 38.8, 24.2, 31.7, 31.3, 45.0 ng/ml in serum, respectively, and 48.4, 24.5, 31.7, 33.1, 52.9 ng/ml for urine, respectively. The method was linear over the range of 50-10000 ng/ml in both matrices with an average linear coefficient (R(2)) value of 0.9918. The injection repeatability and intra-assay precision of the method were evaluated over ten injections, resulting in a percent relative standard deviation <5%. The ADS extraction column was robust, providing many direct injections of biological fluids for the extraction and subsequent determination of benzodiazepines.

Flunitrazepam: an evaluation of use, abuse and toxicity

The benzodiazepine flunitrazepam is extensively prescribed to patients with insomnia in many countries, but has also become popular among alcohol- and drug abusers. Several reports indicate that it is used as a date rape drug and suggest that it may precipitate violent behavior. Furthermore, flunitrazepam is involved in many fatal intoxications in Sweden. This study was designed and conducted to explore the negative consequences of flunitrazepam abuse in Sweden, and to assess the trends in its use and abuse. The occurrence of flunitrazepam in cases referred to the Department of Forensic Chemistry in Linköping, Sweden 1992-1998, was investigated in detail. The detections were studied separately for different groups; medicolegal death investigations, drug abuse cases, driving under influence cases, and other medicolegal cases. These data were further compared with the sales, and seizures by the Swedish Customs and the Swedish Police. During 1992-1998, 641 fatalities occurred, where the cause of death was attributed to intoxication with flunitrazepam solely (130) or in combination with other drugs, or concomitant conditions (511). In 78% of all driving under influence cases, where flunitrazepam was detected, the analyses also disclosed the presence of illicit drugs. A similar association was seen in drug abuse cases. The seizures reported by the Swedish Customs revealed a substantial and increasing illegal trade. Cases, where flunitrazepam seemingly induced violent behavior were identified, and one of these is described in some detail. It is concluded that the abuse pattern and the toxicity of flunitrazepam should be kept in mind by forensic investigators and that this panorama also should be considered when decisions about the registration and classification of flunitrazepam are made in different countries.

Pharmacokinetic interactions between acute alcohol ingestion and single doses of benzodiazepines, and tricyclic and tetracyclic antidepressants -- an update

Recent reports of interactions between alcohol and benzodiazepines, tricyclic and tetracyclic antidepressants during their acute concomitant use are reviewed. Acute ingestion of alcohol (ethanol) with tranquilizers or hypnotics is responsible for several pharmacokinetic interactions that can have significant clinical implications. In general, metabolism of these drugs is delayed when combined with alcohol but some reports have suggested otherwise. The amount of alcohol consumed, the presence or absence of liver disease, and differences in the dosage and administration of these drugs may account for the observed discrepancies. In recent years, the cytochrome P450 (P450 or CYP) isoenzyme that catalyses the metabolism of these drugs has also been identified. However, since changes in the pharmacogenetic metabolism of benzodiazepines and tricyclic and tetracyclic antidepressants are mainly governed by CYP2C19 and CYP2D6, caution is needed when used together with alcohol.

Determination of flunitrazepam and its metabolites in blood by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

A selective assay of flunitrazepam (F) and its metabolites 7-aminoflunitrazepam (7-AF), N-desmethylflunitrazepam (N-DF) and 3-hydroxyflunitrazepam (3-OHF) with liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS, positive ions) is described. The drugs were isolated from serum, blood or urine using a solid-phase extraction procedure previously applied to various drugs of abuse. F-d3 and 7-AF-d3 were used as internal standards. The drugs were separated on ODS column in acetonitrile-50 mM ammonium formate buffer, pH 3.0 (45:55, v/v). After analysis of mass spectra taken in full scan mode, a selected-ion monitoring detection was applied with following ions: m/z 284 (7-AF and F), 287 (7-AF-d3 and F-d3), 314 (F), 300 (N-DF and 3-OHF), 317 (F-d3), 330 (3-OHF). The limits of detection were: 0.2 microg/l for F and 7-AF, 1 microg/l for N-DF and 3-OHF. The method was linear in the range 1-500 microg/l, the recoveries ranged from 92 to 99%. The method was applied for determination of F and metabolites in clinical and forensic samples. LC-APCI-MS seems to be a method of choice for these compounds.

Methods for the measurement of benzodiazepines in biological samples

A review of methods for the measurement of benzodiazepines in biological specimens published over the last five years is presented. A range of immunoassay procedures using EIA, ELISA, FPIA, agglutination or kinetic interaction of microparticles, or RIA methods are now available. Cross reactivities to benzodiazepines are variable such that no one kit will recognise all benzodiazepines and their relevant metabolites at concentrations likely to be encountered during therapeutic use. Prior hydrolysis of urine to convert glucuronide metabolites to immunoreactive substances improves detection limits for many benzodiazepines. Several radioreceptor assays have now been published and show good sensitivity and specificity to benzodiazepines and offer the advantage (over immunoassay) of being able to detect these drugs with equal sensitivity. Solvent extraction techniques using a variety of solvents were still popular and offer acceptable recoveries and lack of significant interference from other substances. A number of papers describing solid phase extraction procedures were also published. Direct injection of specimens into a HPLC column with back flushing were also successfully described. Seventy two chromatographic methods using HPLC, LC-MS, GC and GC-MS methods were reviewed. HPLC was able to achieve detection limits for many benzodiazepines using UV or DAD detection down to 1-2 ng/ml using 1-2 ml of urine or serum (blood). ECD detectors gave detection limits better than 1 ng/ml from 1 ml of specimen, which was an order of magnitude lower than for NPD. EI-MS offered similar sensitivity, whilst NCI-MS was capable of detection down to 0.1 ng/ml. Methods suitable for the separation of enantiomers of benzodiazepines have been described using HPLC. Electrokinetic micellar chromatography has also been shown to be capable of the analysis of benzodiazepines in urine.