Abuse liability of flunitrazepam

Sedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and Selank

There are many nonopioid central nervous system depressant substances that share a gamma-aminobutyric acid (GABA) receptor-related mechanism of action. These sedatives-hypnotics can be indicated to treat anxiety, seizures, depression, and insomnia but are also used as substances of abuse and used to facilitate sexual assault. Barbiturates, methaqualone, and glutethimide were among the first type A GABA receptor-mediated sedative-hypnotics. Their clinical use was limited for most indications by serious adverse events and strong abuse potential but continue to be used illicitly around the world. The benzodiazepines supplanted barbiturates for most indications because they were less likely to cause severe adverse events in monotherapy. Flunitrazepam is a newer benzodiazepine that is preferentially used recreationally and to facilitate sexual assault. Flunitrazepam has greater potency and higher affinity for the type A GABA receptor than most benzodiazepines. Gamma-hydroxybutyric acid is sought illicitly for its hypnotic, euphoric and anabolic effects as well as to facilitate sexual assault. When any of these GABAergic drugs are used in high doses or with other sedative hypnotic agents, respiratory depression, coma, and death have occurred. Chronic use of these GABAergic drugs can lead to significant withdrawal syndromes. Phenibut and selank are poorly studied Russian drugs with GABAergic mechanisms that are inexplicably sold to US consumers as dietary supplements. Poison control center calls regarding phenibut have increased substantially over the past 5 years. Desired euphoriant effects account for the recreational and illicit use of many GABA-modulating agents. However, illicit use can lead to significant toxicities related to abuse, dependence, and subsequent withdrawal syndromes. Significant evaluation of developing agents with GABA properties should be conducted to determine abuse potential before public access ensues.

Designer benzodiazepines versus prescription benzodiazepines: can structural relation predict the next step?

Designer benzodiazepines are a part of the recently discovered abuse synthetic drugs called Novel Psychoactive Substances (NPS) which need to be controlled due to their constantly growing market. Most of them are derived from the medically approved benzodiazepines used nowadays yet, may possess stronger effects, more toxicity, and longer durations of action. Some differences have also been observed in their detection and characteristics, in addition to the variations discovered in postmortem redistribution and drug stability. All these major alterations in features can result from only minor structural modifications. For example, a classic benzodiazepine (BZD) like diazepam only lacks one fluorine atom which exists in its derivatized designer drug, diclazepam, making substantial differences in activity. For this reason, it is essential to study the designer drugs in order to identify their dangers and distinguish them thus rule out their abuse and control the spread of such drugs. This review would highlight the distinct characteristics of some of the most commonly abused designer benzodiazepine analogies in relation to their original prescription BZD compounds.

Early Detection of Prescription Drug Abuse Using Doctor Shopping Monitoring From Claims Databases: Illustration From the Experience of the French Addictovigilance Network

Opioid analgesics and maintenance treatments, benzodiazepines and z-drugs, and other sedatives and stimulants are increasingly being abused to induce psychoactive effects or alter the effects of other drugs, eventually leading to dependence. Awareness of prescription drug abuse has been increasing in the last two decades, and organizations such as the International Narcotics Control Board has predicted that, worldwide, prescription drug abuse may exceed the use of illicit drugs. Assessment of prescription drug abuse tackles an issue that is hidden by nature, which therefore requires a specific monitoring. The current best practice is to use multiple detection systems to assess prescription drug abuse by various populations in a timely, sensitive, and specific manner. In the early 2000's, we designed a method to detect and quantify doctor shopping for prescription drugs from the French National Health Data System, which is one of the world's largest claims database, and a first-class data source for pharmacoepidemiological studies. Doctor shopping is a well-known behavior that involves overlapping prescriptions from multiple prescribers for the same drug, to obtain higher doses than those prescribed by each prescriber on an individual basis. In addition, doctor shopping may play an important role in supplying the black market. The paper aims to review how doctor shopping monitoring can improve the early detection of prescription drug abuse within a multidimensional monitoring. The paper provides an in-depth overview of two decades of development and validation of the method as a complementary component of the multidimensional monitoring conducted by the French Addictovigilance Network. The process accounted for the relevant determinants of prescription drug abuse, such as pharmacological data (e.g., formulations and doses), chronological and geographical data (e.g., impact of measures and comparison between regions), and epidemiological and outcome data (e.g., profiles of patients and trajectories of care) for several pharmacological classes (e.g., opioids, benzodiazepines, antidepressants, and methylphenidate).

Metabolites replace the parent drug in the drug arena. The cases of fonazepam and nifoxipam

Fonazepam (desmethylflunitrazepam) and nifoxipam (3-hydroxy-desmethylflunitrazepam) are benzodiazepine derivatives and active metabolites of flunitrazepam. They recently invaded the drug arena as substances of abuse and alerted the forensic community after being seized in powder and tablet forms in Europe between 2014 and 2016. A review of all the existing knowledge of fonazepam and nifoxipam is reported, concerning their chemistry, synthesis, pharmacology and toxicology, prevalence/use, biotransformation and their analysis in biological samples. To our knowledge, fonazepam and nifoxipam-related intoxications, lethal or not, have not been reported in the scientific literature. All the available information was gathered through a detailed search of PubMed and the World Wide Web.

Enhancing sexual desire and experience: an investigation of the sexual correlates of gamma-hydroxybutyrate (GHB) use

OBJECTIVE

Various studies have dealt with gamma-hydroxybutyrate's (GHB) potential role in sexual assaults, while the sexual correlates of intentional recreational GHB use have not well been highlighted. Our study aims to explore GHB's sexual effects, the patterns of choice of sexual partners, the frequency of experienced blackouts, and endured sexual or acquisitory crimes as a result of GHB use.

METHODS

Sixty recreational GHB users filled out a questionnaire on experienced subjective, somatic, and sexual effects of GHB, the frequency of blackouts due to their GHB use, and items on their sexual experiences in relation to GHB use.

RESULTS

Of the sample, 25.9% reported increased sexual arousal as well as more intense attraction towards their sexual partners and increased sexual openness when using GHB; 34.8% had sexual intercourse with strangers, or with others, but not with their partners when using GHB; and 8.6% were victims of acquisitory crimes, whereas 3.4% were victims of a sexual assault. Furthermore, 24.6% typically experienced blackouts when using GHB.

CONCLUSION

Gamma-hydroxybutyrate seems to be a potential substitute for both stimulant and depressant substances. Increased sexual desire and disinhibition may lead to a more frequent and potentially more riskful sexual activity. Experienced blackouts need to be considered as risk factors for suffering sexual or acquisitory crimes.

Evaluation of cytotoxicity and mutagenicity of the benzodiazepine flunitrazepam in vitro and in vivo

Flunitrazepam (FNZ) is a sedative benzodiazepine prescribed for the short-term treatment of insomnia. However, there are concerns regarding possible carcinogenic or genotoxic effects of this medicine. Thus, the aim of this study was to evaluate the cytotoxic, clastogenic and aneugenic effects of FNZ in hepatoma cells from Rattus norvegicus (HTC) in vitro and in bone marrow cells of Wistar rats in vivo. These effects were examined in vitro following treatment with 0.2, 1.0, 5.0 or 10 μg/mL FNZ using a micronucleus test with a cytokinesis block or in vivo using a chromosomal aberration test following treatment with 7, 15 or 30 μg/mL/kg body weight. The results showed that the benzodiazepine concentrations tested were not cytotoxic, aneugenic or clastogenic. However, considering the adverse effects of using this benzodiazepine, more studies are required.

GABAergic modulation of human social interaction in a prisoner's dilemma model by acute administration of alprazolam

Recent work in neuroeconomics has used game theory paradigms to examine neural systems that subserve human social interaction and decision making. Attempts to modify social interaction through pharmacological manipulation have been less common. Here we show dose-dependent modification of human social behavior in a prisoner's dilemma model after acute administration of the γ-aminobutyric acid (GABA)-A modulating benzodiazepine alprazolam. Nine healthy adults received doses of placebo, 0.5, 1.0, and 2.0 mg alprazolam in a counterbalanced within-subject design, while completing multiple test blocks per day on an iterated prisoner's dilemma game. During test blocks in which peak subjective effects of alprazolam were reported, cooperative choices were significantly decreased as a function of dose. Consistent with previous reports showing that high acute doses of GABA-modulating drugs are associated with violence and other antisocial behavior, our data suggest that at sufficiently high doses, alprazolam can decrease cooperation. These behavioral changes may be facilitated by changes in inhibitory control facilitated by GABA. Game theory paradigms may prove useful in behavioral pharmacology studies seeking to measure social interaction, and may help inform the emerging field of neuroeconomics.

Evidence of clonazepam abuse liability: results of the tools developed by the French Centers for Evaluation and Information on Pharmacodependence (CEIP) network

Recent observations suggest the existence of clonazepam abuse. To determine its importance in France, a quantitative and systematic synthesis of all clonazepam data of several epidemiological tools of the Centers for Evaluation and Information on Pharmacodependence (CEIP) network has been performed in comparison with data on others benzodiazepines (BZD). Data on clonazepam and other BZD have been analysed from different epidemiological tools: OSIAP survey that identifies drugs obtained by means of falsified prescriptions, Observation of Illegal Drugs and Misuse of Psychotropic Medications (OPPIDUM) survey that describes modalities of use and data from regional French health reimbursement system. In OSIAP survey, the proportion of clonazepam falsified prescriptions among all BZD falsified prescriptions increased. During the 2006 OPPIDUM survey, the analysis of the BZD modalities of use highlights clonazepam abuse liability (for example 23% of illegal acquisition), in second rank after flunitrazepam. Studies based on data from the French health reimbursed system show that 1.5% of subjects with clonazepam dispensing had a deviant behaviour. Among BZD, clonazepam has the second most important doctor-shopping indicator (3%) after flunitrazepam. All these data provide some arguments in favour of clonazepam abuse liability in real life and the necessity to reinforce its monitoring.

Superadditive effects of ethanol and flunitrazepam: implications of using immunopharmacotherapy as a therapeutic

While benzodiazepine intoxication alone may elicit sedative and antianxiety effects, alcohol coingestion greatly amplifies this central nervous system depression. As a result, this drug combination gained notoriety for its role in cases of facilitated sexual assault and fatal overdose. We previously validated the ability of the novel antiflunitrazepam monoclonal antibody (mAb) RCA3A3 to bind flunitrazepam (FLU) in vivo and block FLU-induced impairment of locomotion and memory. A therapeutically relevant application of this high affinity mAb (K(d,app) = 200 nM), however, is to the more tenuous indication of flunitrazepam (FLU) and alcohol cointoxication. Employing a murine behavioral model, passive immunization with mAb RCA3A3 before injection of ethanol (EtOH: low-dose, 1 g/kg, or high-dose, 1.5 g/kg), FLU (0.06 mg/kg), or a cocktail of both drugs offered partial to full restoration of motor activity levels in co-drug treated and FLU-treated mouse groups (n = 12), respectively. Whereas all drug treatments left contextual learning intact, auditory cued learning was severely disrupted. Prophylactic administration of mAb RCA3A3 prevented this deficit in cued learning in FLU-treated mice but not in the FLU- and EtOH-treated mice, in which co-drug exposure exacerbated the impairment in cued fear conditioning. To substantiate this finding, a dose-response study was performed, and the changes in locomotor activity incurred by different FLU (low-dose, 0.06 mg/kg, or high-dose, 0.09 mg/kg), EtOH (1.0 g/kg, 1.5 g/kg), and mAb RCA3A3 (14.5 mg/kg, 21.8 mg/kg) dose combinations illustrated the potentiation in motor effects by concomitant exposure to FLU and EtOH. Thus, motor activity and fear conditioning results demonstrated that both the amount of FLU left unbound by antibody and the pharmacological additivity between FLU and EtOH, a GABA mimetic, were limiting factors in the therapeutic efficacy of mAb RCA3A3. In sum, our study highlights the complex nature of psychomotor impairment upon co-drug versus singular drug exposure, which may pose a unique challenge to therapeutic treatment.

Assessment of abuse potential of benzodiazepines from a prescription database using 'doctor shopping' as an indicator

BACKGROUND

Benzodiazepines are widely used for different purposes because of their pharmacological properties, but their abuse potential may represent a limitation to their use. Data suggest that this abuse potential may vary between products and available dosages. Doctor shopping (the simultaneous use of several physicians by a patient) is one of the most important ways in which prescription drugs, in particular benzodiazepines, are diverted.

OBJECTIVE

To assess the potential for abuse of several benzodiazepines using doctor shopping in a French administrative area as a proxy for abuse.

METHODS

All prescriptions reimbursed during the year 2003 in Haute-Garonne, France (one million inhabitants) for benzodiazepines that were available in ambulatory care through community pharmacies as solid oral forms were extracted from a reimbursement database. The benzodiazepines were alprazolam (0.25 mg, 0.50 mg), bromazepam 6 mg, clonazepam 2 mg, clorazepate (5 mg, 10 mg, 50 mg), diazepam (1 mg, 5 mg, 10 mg), flunitrazepam 1 mg, lorazepam (1 mg, 2.5 mg) and tetrazepam 50 mg. For each patient, the quantities prescribed, dispensed and obtained by doctor shopping (i.e. overlap between prescriptions from different prescribers) were computed. Benzodiazepines were compared using their 'doctor shopping indicator' (DSI, the percentage of each drug obtained through doctor shopping among the total reimbursed quantity).

RESULTS

About 128 000 patients received at least one benzodiazepine during the year. Four groups of benzodiazepines were identified according to their abuse potential: very high abuse potential (flunitrazepam, DSI = 42.8%); high abuse potential (diazepam 10 mg, DSI = 3.2%; clorazepate 50 mg, DSI = 2.7%); intermediate abuse potential (alprazolam 0.50 mg, bromazepam, clonazepam, DSI ranging from 1.8% to 1.9%); and low abuse potential (other benzodiazepines and dosages, DSI ranging from 0.3% to 1.1%).

CONCLUSION

The DSI can be used to assess the relative abuse liability of benzodiazepines and to detect signals of new patterns of abuse in settings where centralized records of prescription or deliveries are available for the great majority of patients.

GABAA receptor alpha2/alpha3 subtype-selective modulators as potential nonsedating anxiolytics

Nonselective benzodiazepines exert their pharmacological effects via GABAA receptors containing either an alpha1, alpha2, alpha3, or alpha5 subunit. The use of subtype-selective tool compounds along with transgenic mice has formed the conceptual framework for defining the requirements of subtype-selective compounds with potentially novel pharmacological profiles. More specifically, compounds which allosterically modulate the alpha2 and/or alpha3 subtypes but are devoid of, or have much reduced, effects at the alpha1 subtype are hypothesized to be anxioselective (i.e., anxiolytic but devoid of sedation). Accordingly, three compounds, MRK-409, TPA023 and TPA023B, which selectively potentiated the effects of GABA at the alpha2 and alpha3 compared to alpha1 subtypes were progressed into man. All three compounds behaved as nonsedating anxiolytics in preclinical (rodent and primate) species but, surprisingly, MRK-409 produced sedation in man at relatively low levels of occupancy (< 10%). This sedation liability of MRK-409 in man was attributed to its weak partial agonist efficacy at the alpha1 subtype since both TPA023 and TPA023B lacked any alpha1 efficacy and did not produce overt sedation even at relatively high levels of occupancy (> 50%). The anxiolytic efficacy of TPA023 was evaluated in Generalized Anxiety Disorder and although these clinical trials were terminated early due to preclinical toxicity issues, the combined data from these incomplete studies demonstrated an anxiolytic-like effect of TPA023. This compound also showed a trend to increase cognitive performance in a small group of schizophrenic subjects and is currently under further evaluation of its cognition-enhancing effects in schizophrenia as part of the TURNS initiative. In contrast, the fate of the back-up clinical candidate TPA023B has not been publicly disclosed. At the very least, these data indicate that the pharmacological profile of compounds that differentially modulate specific populations of GABAA receptors is distinct from classical benzodiazepines and should encourage further preclinical and clinical investigation of such compounds, with the caveat that, as exemplified by MRK-409, the preclinical profile might not necessarily translate into man.

Estimation of clonazepam abuse liability: a new method using a reimbursed drug database

Some observations suggest the existence of clonazepam abuse. The aim of this study was to assess its magnitude in real life by a new method, using a prescription database, and to assess its evolution between 2001 and 2006. Individuals from a region affiliated to the French health reimbursement system, who had a prescription of clonazepam reimbursed between 1 January and 15 February of two selected years were included. Their deliveries were monitored over a 9-month period. After a descriptive analysis, a clustering method illustrated by a factorial analysis was used to identify different subgroups of clonazepam consumers. An increase of 82% in participants who had a delivery of clonazepam between 2001 and 2006 was observed. Using the clustering method, this study identified some deviant participants. This group comprises a higher proportion of males, benzodiazepine users, and buprenorphine users. The number of deliveries by different prescribers and pharmacies are higher. The proportion of deviant participants increased between 2001 and 2006 (from 0.86 to 1.38%). Our method can be used to assess the magnitude of abuse liability of clonazepam and is also interesting for following its evolution, two important keys for assessing patterns of abuse.

Self-perceived motivation for benzodiazepine use and behavior related to benzodiazepine use among opiate-dependent patients

Clinical observations have shown a high prevalence of benzodiazepine use among opiate-dependent patients. Our objective was to identify if distinct patterns of behavior could be associated with three different self-perceived motivations for benzodiazepine use: (a) exclusive self-therapeutic motivation, (b) exclusive hedonic motivation, and (c) combined self-therapeutic and hedonic motivation. Data were collected through a self-administered questionnaire in 92 opiate users in treatment in France (Aquitaine). The behaviors associated with exclusive self-therapeutic motivation included the search for an anxiolytic effect, oral administration, use within the context of a medical prescription, and use without other substances. The behaviors associated with exclusive hedonic motivation were use in combination with other substances, the obtaining of benzodiazepines by the black market, and use of other routes of administration in search of a "blackout." Among patients who reported both motivations, there were distinct trends of behavior according to motivation.

Characterization of Escherichia coli nitroreductase NfsB in the metabolism of nitrobenzodiazepines

Nitrobenzodiazepine (NBDZ) is a sedative-hypnotic drug used in the treatment of anxiety and sleep problems. Overdose of NBDZ may cause severe neurological effects, especially for people in drug abuse or addiction. In the present study, we investigated NBDZ nitroreduction in rat enteric contents and characterized the role of enterobacterial nitroreductase in the reductive pathway. Nitroreduction of flunitrazepam (FZ) was studied in the microsomal membrane fractions of rat liver, jejunum and jejunal microflora using HPLC analysis. In the jejunal microflora, FZ was demonstrated to be significantly reduced to its amino derivative under anaerobic condition. Escherichia coli type I nitroreductase NfsB (EC 1.5.1.34) was found in rat jejunal microflora via PCR technique and Western blotting. The participation of NfsB in FZ nitroreduction was demonstrated from inhibition studies. Kinetic study of the purified recombinant NfsB indicated that nitroreduction of FZ, nitrazepam (NZ) and clonazepam (CZ) are mediated by NfsB, where CZ shows lower k(cat)/K(M) ratio than that of the other two. Finally, two other nitroreductases E. cloacae NR (EC 1.6.99.7) and S. typhimurium Cnr were also found to be responsible for FZ nitroreduction. These results provide that the reduction of NBDZ in normal flora is catalyzed by type I nitroreductase NfsB.

Modulation of human risky decision making by flunitrazepam

RATIONALE

GABA-modulating drugs produce disinhibitory effects that increase the probability of risk-taking behavior. Previous reports suggest that the misuse of the benzodiazepine flunitrazepam is associated with several forms of harmful risky behavior, including theft, violence, and intoxication-related auto accidents.

OBJECTIVES

The present study examined the dose-response relationships between acute flunitrazepam administration and human decision making under conditions of risk. The analyses also examined flunitrazepam-mediated changes in decision-making processes using a computational modeling approach, the expectancy valence model (EVM).

MATERIALS AND METHODS

Using a laboratory measure of risky decision making designed to address acute drug effects, 12 adults were administered placebo, 0.5, 1.0, and 2.0 mg/70 kg flunitrazepam in a within-subject, repeated measures counterbalanced design. Flunitrazepam was compounded and doses were administered in an 8-oz liquid solution. Primary data analyses examined subjective effects, response rates, distribution of choices between the risky and nonrisky option, and personality correlates related to peak drug effects. Individual-subject data were submitted to a computational modeling analysis (EVM) that provided parameter estimates corresponding to components of valence; updating expectancies about alternatives (learning/memory); and consistency between choices and expected outcomes (sensitivity to learned outcomes).

RESULTS

Flunitrazepam produced dose-related changes in subjective effects and response rates, and increased selection of the risky response option. High doses significantly changed decision-making processes related to the learning/memory and consistency parameters.

CONCLUSIONS

At sufficiently high doses, flunitrazepam can engender increases in risky decision making. Globally, these changes appear similar to previous effects we have observed after acute administration of alcohol and alprazolam. As suggested by the EVM outcomes, the mechanisms underlying the changes in risky decision making are more similar to alprazolam than alcohol.

Sevrage aux benzodiazépines des sujets dépendants aux opiacés en traitement de substitution

INTRODUCTION

Benzodiazepines are the most widely used psychotropic agents in the world. Abuse and dependence are reported in the general population and among drug misusers, including those dependent on heroine. Benzodiazepine use by heroine users increases their risk of overdose, not only from heroin but also substitution drugs such as methadone and more recently buprenorphine. Hence, detoxification from benzodiazepines is desirable.

OBJECTIVE

The objective of this paper was to review the literature and determine the best benzodiazepine detoxification procedure for opiate-dependent individuals receiving substitution treatment.

METHODS

Relevant studies were sought through systematic searches of Medline and Toxibase (a database focusing on substance abuse).

RESULTS

There were fewer controlled studies than expected about benzodiazepine detoxification, and all of them excluded subjects who misused opiates or were in opiate substitution treatment. The best evidence supports a procedure where the patient is switched to a long-lasting benzodiazepine and the dose then tapered by 25% of the initial dose each week. Diazepam is the drug most often used in the framework. In opiate users, diazepam may raise special problems of misuse, as suggested by clinical and epidemiologic studies. Nonetheless, diazepam is the only benzodiazepine found to be effective for this withdrawal in controlled studies and some studies indicate that unprescribed diazepam use in heroin users is sometimes motivated by the desire to alleviate withdrawal symptoms and discomfort.

CONCLUSION

Although diazepam appears to have potential for abuse, the available data does not rule out its therapeutic interest for benzodiazepine withdrawal in patients on opiate substitution treatment in an adequate treatment setting. Specific studies of this population are needed.

An abuse liability comparison of flunitrazepam and triazolam in sedative drug abusers

The present double-blind, placebo-controlled study compared the acute effects of oral administration of the benzodiazepine hypnotics flunitrazepam (6 mg/70 kg) and triazolam (1 and 2 mg/70 kg) on measures relevant to abuse liability as well as on psychomotor performance and observer- and participant-rated measures of drug effects in nine sedative drug abusers. Analysis of participant-rated measures collected 24 h after drug administration (next-day; assessing the overall effects of the drug received 24 h earlier) indicated that flunitrazepam, but neither triazolam dose, produced significant increases relative to placebo in next-day ratings of drug liking, the amount of money the drug would be worth on the street, and the amount of money the participant would be willing to pay for the drug on the street. Importantly, these abuse liability differences between flunitrazepam and triazolam were present at a dose of flunitrazepam (6 mg/70 kg) that produced overall drug effects that were comparable to, or significantly less than, those of a high triazolam dose (2 mg/70 kg). Consistent with results of a previous study in our laboratory, these results suggest that flunitrazepam may have a greater abuse liability than triazolam, and that this abuse liability difference emerges on measures taken 24 h after drug administration but not on same-day measures.

Toxicological findings in cases of alleged drug-facilitated sexual assault in the United Kingdom over a 3-year period

This paper outlines the toxicology results from 1014 cases of claimed drug-facilitated sexual assault (DFSA) analysed at the Forensic Science Service, London Laboratory between January 2000 and December 2002. Where appropriate, either a whole blood sample and/or a urine sample was analysed for alcohol, common drugs of abuse and potentially stupefying drugs. The results were interpreted with respect to the number of drugs detected and an attempt was made to distinguish between voluntary and involuntary ingestion from information supplied. Alcohol (either alone or with an illicit and/or medicinal drug) was detected in 470 of all cases (46%). Illicit drugs were detected in 344 cases (34%), with cannabis being the most commonly detected (26% of cases), followed by cocaine (11%). In 21 cases (2%), a sedative or disinhibiting drug was detected which had not been admitted and could therefore be an instance of deliberate spiking. This included three cases in which complainants were allegedly given Ecstasy (MDMA) without their knowledge. Other drugs detected included gammahydroxybutyrate (GHB) and the benzodiazepine drugs diazepam and temazepam. Another nine cases (1%) involved the complainant being either given or forced to ingest pharmaceutical tablets or an illicit drug.

Recognition and management of complications of new recreational drug use

Use of illicit drugs in clubs and large dance parties (so-called raves) is a burgeoning cultural trend. Such recreational drug use is associated with several medical complications, both acute and longlasting. Although few, if any, of the drugs currently used in recreational venues are truly new, their patterns and context of use have changed (a great deal in some instances). For some of these substances, this cultural repackaging of the drug experience has resulted in various medical disorders that have previously gone undocumented. This review aims to help treating physicians recognise and manage complications associated with the use of new drugs in clubs, including methylenedioxymethamfetamine, ephedrine, gamma-hydroxybutyrate; gamma-butyrolactone, 1,4-butanediol, flunitrazepam, ketamine, and nitrites. We also alert researchers to specific toxic effects of club-drugs on which more basic information is needed.

Self-injection of flunitrazepam alone and in the context of methadone maintenance in baboons

Patients in methadone maintenance programs use benzodiazepines to "boost" methadone's subjective effects, and flunitrazepam has been prominent in this context. Self-administration of flunitrazepam (0.001-0.32 mg/kg i.v.) alone and during daily oral methadone administration was evaluated in three baboons. Flunitrazepam maintained self-injection as an inverted U-shaped function of dose at rates higher than those maintained by most other benzodiazepines under the same procedure. In the context of demonstrated physical dependence on 3.2 mg/kg/day p.o. methadone, flunitrazepam doses on the ascending limb of the dose-effect curve maintained greater rates of self-injection than before methadone in two baboons. When the methadone dose decreased to 1.8 mg/kg/day, self-injection remained higher for those baboons and became higher than before methadone for the third baboon. Self-injection remained higher when methadone decreased to 1.0 mg/kg/day, except self-injection of the lowest flunitrazepam dose returned to or below the pre-methadone rate for two baboons. After methadone was discontinued, the dose-effect curve shifted to the right in one baboon but remained to the left in two. Flunitrazepam thus served as a reinforcer alone and in the context of methadone maintenance. Lower doses maintained higher self-injection during and shortly after methadone maintenance. Further research should explore the duration of higher self-injection rates following methadone maintenance.

Postmortem toxicology of drugs of abuse

Conducting toxicology on post-mortem specimens provides a number of very significant challenges to the scientist. The range of additional specimens include tissues such as decomposing blood and other tissues, hair, muscle, fat, lung, and even larvae feeding on the host require special techniques to isolate a foreign substance and allow detection without interference from the matrix. A number of drugs of abuse are unstable in the post-mortem environment that requires careful consideration when trying to interpret their significance. Heroin, morphine glucuronides, cocaine and the benzodiazepines are particularly prone to degradation. Moreover, redistributive process can significantly alter the concentration of drugs, particularly those with a higher tissue concentration than the surrounding blood. The designer amphetamines, methadone and other potent opioids will increase their concentration in blood post-mortem. These processes together with the development of tolerance means that no concentration of a drug of abuse can be interpreted in isolation without a thorough examination of the relevant circumstances and after the conduct of a post-mortem to eliminate or corroborate relevant factors that could impact on the drug concentration and the possible effect of a substance on the body. This article reviews particular toxicological issues associated with the more common drugs of abuse such as the amphetamines, cannabinoids, cocaine, opioids and the benzodiazepines.

NADPH-cytochrome P-450 reductase is involved in flunitrazepam reductive metabolism in Hep G2 and Hep 3B cells

Flunitrazepam (FNTZ), like other benzodiazepines, has a high affinity for the benzodiazepine receptor within the gama-aminobutyric acid (GABA) complex. These affinities correlate with the pharmacological and therapeutic potencies of the drug. FNTZ is a drug commonly abused by young adults. In humans, FNTZ is oxidized to the major metabolites N-demethylflunitrazepam (DM FNTZ) and 3-hydroxyflunitrazepam (3-OH FNTZ) and reduced to 7-aminoflunitrazepam (7A FNTZ). Human CYP2C19 and CYP3A4 are the principal P-450 cytochromes involved in DM FNTZ and 3-OH FNTZ formation. However, it is not clear which enzyme is responsible for the reduction of FNTZ to 7-aminoflunitrazepam (7A FNTZ). In this study, the involvement of NADPH-cytochrome P-450 reductase in the conversion of FNTZ to 7A FNTZ was investigated in two human hepatoma cell lines, human lymphoblast microsomes specifically expressing human NADPH-cytochrome P-450 reductase and purified recombinant human HADPH-cytochrome P-450 reductase. Significantly more FNTZ was converted to 7A FNTZ in Hep G2 than in Hep 3B cells, and this difference was associated with the catalytic activity and protein levels of NADPH-cytochrome P-450 reductase in these cells. In Hep G2 cells, conversion of FNTZ to 7A FNTZ was effectively inhibited by alpha-lipoic acid, an NADPH-cytochrome P-450 reductase inhibitor. In addition, formation of 7A FNTZ by the microsomal fraction of Hep G2 cells was specifically inhibited by antibody against NADPH-cytochrome P-450 reductase. Under hypoxia (N2 85%; CO2 5%; H2 10%), human lymphoblast microsomes specifically expressing human NADPH-cytochrome P-450 reductase and purified recombinant human NADPH-P-450 reductase catabolized FNTZ to 7A FNTZ in a concentration-dependent manner. These results suggest that NADPH-cytochrome P-450 reductase is involved in the reductive metabolism of FNTZ to 7A FNTZ under hypoxic conditions.

The role of cytochrome P450 2C19 activity in flunitrazepam metabolism in vivo

Flunitrazepam, a hypnotic benzodiazepine, is widely prescribed around the world for the treatment of insomnia and as a preanesthetic. In vitro studies have shown that the metabolism of flunitrazepam to desmethylflunitrazepam and 3-hydroxyflunitrazepam is mediated in part by the polymorphic enzyme CYP2C19. The objective was to examine the role of CYP2C19 activity in determining flunitrazepam kinetics in vivo. Sixteen healthy volunteers (14 genotypic extensive metabolizers and 2 poor metabolizers) were recruited who had a wide range of CYP2C19 activity (0.50-28.8), as determined by the omeprazole/ 5-hydroxyomeprazole ratio (OMR) at 3 hours following administration of omeprazole, 20 mg orally. Each subject received flunitrazepam, 1 mg orally. Blood samples were collected immediately before and up to 48 hours after drug administration and were assayed by HPLC for flunitrazepam and its metabolites, 7-aminoflunitrazepam, desmethylflunitrazepam, and 3-hydroxyflunitrazepam. Spearman correlations were determined for OMR and pharmacokinetic parameters. With increasing OMR (decreasing CYP2C19 activity), the ratio of flunitrazepam to both desmethylflunitrazepam and 3-hydroxyflunitrazepam AUCs increased ( r = 0.55, p = 0.03 and r = 0.65, p = 0.01, respectively). However, variation in CYP2C19 activity did not significantly affect the AUCs of flunitrazepam or its metabolites. The authors conclude that CYP2C19 contributes to the metabolism of flunitrazepam to desmethylflunitrazepam and 3-hydroxyflunitrazepam in vivo, but these data suggest that its role is minor and that differences in CYP2C19 activity do not likely substantially influence its clinical effects.

Buprenorphine prescription by general practitioners in a French region

Since 1996 French general practitioners (GPs) may prescribe sublingual buprenorphine tablets as maintenance treatment for opiate dependence. The computerised data management of the main French health reimbursement system now allows surveillance of the use of this drug, and how it is prescribed. The purpose of this study is to determine the profile of maintained patients, prescribed doses, associated psychotropic treatments and how practitioners prescribe these treatments. This study analyses the 11186 buprenorphine prescriptions electronically transmitted for reimbursement between September and December 1999 in a specific French region. It was found that the 2078 treated patients consumed a mean of 11.5 mg of buprenorphine per day and 12% of them procured prescriptions from more than two prescribers. 43% of maintained patients had an associated benzodiazepine prescription, mainly flunitrazepam, often on the same prescription form. 61% of patients had regular follow-up, others had occasional consultations (21%) and another 18% had deviant maintenance treatment (more than two prescribers or more than 20 mg per day of daily buprenorphine dose). Benzodiazepine consumption was much higher in the 'deviant group' (71.4%). 85% of buprenorphine prescriptions were made by GPs. 21% of GPs prescribed buprenorphine and 61% of those had only one or two maintained patients. Buprenorphine prescription by French GPs is a procedure with no particular requirements, allowing many patients to easily access maintenance treatments. However, a high risk of abuse exists, which demands extensive investigation and evaluation of these practices.

Forensic urinalysis of drug use in cases of alleged sexual assault

The results of 3303 analyses of urine samples, collected in an independent testing programme from individuals who claimed to have been sexually assaulted and believed that drugs were involved, were examined in detail. Of the samples provided, 2026 (61.3%) proved positive for one or more substances. Alcohol, either alone or in combination with other drugs, was by far the commonest substance found, being present in 1358 samples (67.0% of positives). Cannabis was the second most prevalent drug, present in 613 samples, (30.3% of positives). Detailed examination of the testing results does not support the contention that any single drug, apart from alcohol, can be particularly identified as a 'date rape' drug. Rather, the alleged sexual assaults may often take place against a background of licit or recreational alcohol or drug use, where alcohol and other drugs are frequently taken together. The extensive forensic database examined here does not support the concept of a commonly occurring 'date rape' scenario, in which the victim's drink is covertly 'spiked' with a tablet, capsule or powder containing a sedative-hypnotic. This research highlights the need for the early collection of forensic samples in cases of alleged sexual assault. Law enforcement agencies and health professionals should establish guidelines and procedures to ensure that appropriate forensic samples (blood and urine) are collected in a timely manner following allegations of possible drug mediated sexual assault.

Modulation of rate of onset and intensity of drug effects reduces abuse potential in healthy males

Low, medium, and high doses of flunitrazepam were tested in three independent randomized, double-blind, balanced cross-over, placebo-controlled trials to study the influence of rate of onset of effects and dose administered on its acute effects. Three groups of 12 healthy male volunteers received six oral doses of placebo or flunitrazepam in slow and fast onset conditions as follows: six capsules of 0.16 mg (slow) and a single capsule of 0.8 mg (fast) in the low dose trial; six 0.25 mg (slow) and a single 1.25 mg (fast) capsules for medium dose; and six 0.4 mg (slow) and a single 2 mg (fast) capsule for high dose. At each dose level, slow or fast increasing flunitrazepam plasma concentrations lead to similar peak levels, but induced differential subjective and behavioral effects. In addition to objective and subjective sedation, flunitrazepam induced some pleasurable feelings, which were more intense in the fast than in the slow conditions. At the highest dose, unpleasant sedative effects surmounted positive effects, while at the lowest dose pleasurable effects were of low intensity. At the medium dose, the balance between pleasurable and unpleasant feelings resulted in euphorigenic effects, which were evident in the fast condition but were blunted in the slow condition.

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.

Flunitrazepam abuse and personality characteristics in male forensic psychiatric patients

Sixty male non-psychotic forensic psychiatric patients (aged 16-35 years) were studied after they completed their ordinary forensic psychiatric assessment (FPA). The prevalence of flunitrazepam (FZ) abuse was investigated by using both structured and in-depth interviews with the objective of studying the relationship between the abuse and personality traits. The patient's characteristics, DSM-IV disorders, and actual sentences were obtained by studying their files. In order to obtain measures on their personality traits, self-report inventories were administered to the patients. Eighteen out of 60 patients were FZ abusers, but only 4 of them received a diagnosis related to the FZ abuse during the ordinary FPA. In almost all cases, however, indications of the FZ abuse were found in the files. No differences in personality traits were found between the groups. The frequency of previous admissions to an FPA and actual sentences of robbery, weapons offenses, narcotic-related offenses, and other crimes (such as theft) among the FZ abusers deviated significantly from forensic non-FZ abusers. Therefore, the FZ abuse per se might be more responsible for their tendency to commit crimes characterized by danger and thrill-seeking (such as robbery, weapons offences, and theft) than personality. The most important conclusion is that assessment of FZ abuse is needed in forensic psychiatry.

Behavioral effects of flunitrazepam: reinforcing and discriminative stimulus effects in rhesus monkeys and prevention of withdrawal signs in pentobarbital-dependent rats

Flunitrazepam was evaluated in several procedures that have been used extensively to study the behavioral effects and abuse potential of positive GABA(A) modulators. One group of monkeys (n=3) responded to receive injections of methohexital or saline (i.v.) while other groups (n=2-4/group) discriminated vehicle from either pentobarbital or triazolam. Other monkeys (n=2) received diazepam daily and discriminated flumazenil from vehicle. Finally, the ability of flunitrazepam to prevent the emergence of withdrawal signs in pentobarbital-treated rats was evaluated. Flunitrazepam maintained i.v. self-administration that was, on average, less than that maintained by methohexital and greater than that maintained by saline. In drug discrimination studies, flunitrazepam substituted for pentobarbital and for triazolam and failed to substitute for flumazenil. In rats (n=3-6/group), signs of withdrawal were not evident when flunitrazepam treatment replaced pentobarbital treatment; withdrawal signs emerged when either pentobarbital or flunitrazepam treatment was terminated. Taken together with data from previous studies, these data suggest that the abuse liability of flunitrazepam is comparable to that of other benzodiazepines.

Recent evolution in opiate dependence in France during generalisation of maintenance treatments

Two maintenance drugs had been used in France since 1996, methadone and high-dosage buprenorphine. This study aimed to examine changes in drug use from observations gathered between 1995 and 1997, within the framework of the French program for the monitoring of drug dependence (OPPIDUM). This annual survey studies psychoactive substances consumed by drug addicts attending specialised drug care centres. During the last three surveys, 16 centres collected a total of 1597 patient-files. This study shows an increase in the number of patients undergoing maintenance treatment (from 14 to 69%), a reduction in the number of intravenous drug users (from 55 to 22%) and a reduction in consumption of psychoactive substances. However, poly-drug addiction behaviour continues and high-dose buprenorphine subjects frequently use the substance intravenously and in association with benzodiazepines.

Trends in recommendations for the pharmacotherapy of anxiety disorders by an international expert panel, 1992-1997

A follow-up survey in 1997 to a 1992 study of the recommendations of an international expert panel on the use of benzodiazepines (BZDs) and other psychotherapeutic medications in the treatment of anxiety disorders suggests that the BZDs remain a mainstay of pharmacotherapy for most of these conditions. BZDs were mentioned more often than any other class of drugs as preferred first-line therapy for anxiety disorders, except obsessive compulsive disorder. The introduction of the selective serotonin reuptake inhibitors (SSRIs) did not significantly affect the experts' recommendations for the use of BZDs as first-line pharmacotherapy. Rather, the SSRIs displaced the tricyclic antidepressants. Some implications of the continuing recommendations for the use of BZDs in anxiety disorders are discussed.

Characteristics of benzodiazepine abuse in methadone maintenance treatment patients: a 1 year prospective study in an Israeli clinic

We aimed to study the prevalence patterns and course of benzodiazepine (BZD) abuse in an Israeli methadone maintenance (MMT) clinic using repeated random observed urine analysis as well as self-report data. Lifetime and current prevalence of BZD abuse were found in 66.3 and 50.8% patients, respectively. It was found that 44.6% of patients who abused BZDs during their first month of treatment ceased to do so after 1 year, while 27.4% who had not abused BZDs at the beginning of MMT did so after 1 year in treatment. Flunitrazepam was the most commonly abused BZD (92.9%), followed by diazepam (54.3%) and oxazepam (38.6%). Most of the patients swallowed BZDs (92.8%), 42.9% also smoked or snorted them while 8.6% injected BZDs intravenously. BZDs were used as self-medication for alleviating emotional problems rather than for recreational or other reasons. We conclude that BZD abuse is a significant clinical problem in heroin addicts both before entering and during MMT. MMT may have a positive as well as a negative influence on BZD abuse with the former being more prevalent.

Flunitrazepam and triazolam: a comparison of behavioral effects and abuse liability

The performance, observer-rated, and participant-rated effects of orally administered placebo, and two benzodiazepines, flunitrazepam (2, 4 and 8 mg/70 kg) and triazolam (0.25, 0.5 and 1 mg/70 kg), were compared in 14 sedative drug abusers using a double-blind crossover design. Both flunitrazepam and triazolam produced dose-related decrements in memory and psychomotor/cognitive performance, and increases in many participant- and observer-rated measures. Effects of flunitrazepam had an earlier onset and a longer duration than those of triazolam. Although there was evidence that the flunitrazepam doses selected for study were somewhat higher overall relative to the selected triazolam doses, analysis of the participant-rated measures collected 24 h after drug administration (next-day) suggests that flunitrazepam may have a greater abuse liability than triazolam when abuse liability is assessed 24 h after drug administration. The highest flunitrazepam dose produced effects that were significantly greater than those of the highest triazolam dose on next-day ratings of good effects, take again, and worth; all tested flunitrazepam doses produced effects greater than any triazolam dose on next-day ratings of liking and take again. The highest flunitrazepam dose, but no triazolam dose, significantly increased the maximum dollar value at which participants chose drug over money in a Drug versus Money Choice Procedure.

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.

Use and abuse of flunitrazepam

Flunitrazepam is not available in the US, and it is presently illegal to import it. Flunitrazepam has no therapeutic advantage over benzodiazepines presently marketed in the US. Its quick onset of sedation, amnesic properties, and additive effects with alcohol have led to its reputation as a party drug, club drug, or date rape drug. Several measures have been undertaken to curb its illicit use. It is unclear whether flunitrazepam poses a greater public health risk than other benzodiazepines.