LAUSR

To the Editor: Benzodiazepines are a class of drugs widely prescribed for the treatment of anxiety, insomnia, epilepsy, muscle spasms or alcohol withdrawal. Reactive to GABA type A receptors, benzodiazepines have a rapid and weakly toxic symptomatic efficacy. This class of drugs is often diverted from the medical use both by opiates addicts or recreative abusers. Indeed, the extensive research around their chemical structures resulted in a wide variety of active compounds that never got a marketing authorization and which are now picked up by online e-merchants of new psychoactive substances and sold under the name “designer benzodiazepines”. The first example of illegal use of non-prescribed benzodiazepine was phenazepam, developed in the Soviet Union in the 1970s. Since the end of year 2010, designer benzodiazepines were proposed as recreational drugs. These drugs were etizolam, metizolam, pyrazolam, flubromazepam, flubromazolam, clonazolam, meclonazepam and nifoxipam. These compounds are sold as tablets, powder or blotters, at very affordable prices. The deleterious effects of designer benzodiazepines depend on the dose consumed. The most common side effects at low doses are drowsiness, fatigue and lethargy. At higher doses, motor coordination disorders, dizziness, mood swings and euphoria may occur. The slow elimination of some benzodiazepines causes their accumulation in lipid-based tissues, which can lead to a delayed overdose in case of repeated consumption. After a long period of consumption, the abuser can develop tolerance and dependence. Sudden drug discontinuation can cause a withdrawal symptom. Severe effects occur when designer benzodiazepines are consumed in combination with opioids. Both pharmacological classes induce a synergistic effect and a respiratory depression (1). Abuse is widespread among poly-consumers, because designer benzodiazepines balance the euphoria due to opioids. Some benzodiazepines have a marked amnesic effect and the consumer loses memory for a few hours after administration (2). The detection of designer benzodiazepines in biological fluids is challenging owing to the very few available data. Some of these compounds have been detected using immunoassays such as ELISA with high cross-reactivity, demonstrating that designer benzodiazepines can be detected during standard blood or urine drug screening. A few authors have developed methods to study the elimination rate and the metabolism of specific drugs, including etizolam (3, 4), metizolam (5–7), meclonazepam (4, 8), diclazepam (4, 9, 10), flubromazolam (11, 12), pyrazolam (11), flubromazepam (13), adinazolam, cloniprazepma, fonazepam, 3-hydroxyphenazepam and nitrazolam (7). Currently, there is no citation and no data for flunitrazolam testing in blood, urine and alternative biological specimens, such as oral fluid (PubMed consultation on 8 November 2017). Flunitrazolam was discovered in the 1960s but has never been marketed for unknown reasons. Its chemical structure is close to flunitrazepam, although flunitrazolam has a triazolo cycle. Scientists have very little information about doses, effects and tolerability. In order to be able to interpret data on flunitrazolam and to obtain information on its detectability in oral fluid, one of the authors (male, 56 years old, 85 kg) ingested one pink tablet bought on the internet and declared to contain 0.25mg of active material. Oral fluid was collected over 8 h using the NeoSalTM (Neogen) device, used as recommended by the manufacturer by handing the pad in the mouth for 2 min. Immediately thereafter, the pad was placed into the buffer, present in a plastic tube. No blood sample was collected, as this requires specific authorizations due to the invasive nature of this specimen. All oral fluid samples were stored at +4°C until analysis. For identification and characterization of flunitrazolam, nuclear magnetic resonance (NMR) spectroscopy was applied (5). No significant impurity was detected in the tablet. In addition, the dosage of one tablet, using the ERETIC (Electronic Reference To access In vivo Concentrations) method, revealed a dosage of 0.23mg of flunitrazolam, in agreement with the announced 0.25mg. All oral fluid samples were submitted to UPLC–MS-MS analysis on an Acquity class I ultra-high performance liquid chromatography coupled to a Xevo TQD tandem mass spectrometer (UPLC–MS-MS)