[The current aspects of the use of ecstasy/MDMA in France]. / Les aspects actuels de l'usage de l'ecstasy/MDMA en France.

Methylenedioxymethamphetamine (MDMA), the active compound of ecstasy, has been used for several years, especially by young adults to benefit of psychostimulant properties. By raising the level of neuromodulators in the synapsis, MDMA can cause psychiatric and physical injuries. After reduced supplies in 2009 (number of ecstasy seizures equal to 10 percent of those recorded in 2002), judicial authorities now observed an increased availability (a half more part of seizures in 2012 than 2010). From its "Spontaneous Notifications" data base and "deaths in connection with the abuse of medicine and substances (DRAMES)", "observation of illegal drugs and misuse of psychotropic medications" (OPPIDUM), and "observation of drug dependencies in ambulatory medicine" (OPEMA) national inquiries, the French Addictovigilance network (CEIP-A) highlighted the increasing consumption of MDMA. The way of use appeared quite unchanged: users were mainly young men between 25 and 30 years; they favored an occasional use but mainly combined other products such as alcohol, cannabis and other stimulants. Severity of the clinical cases, based on hospital care and forensic data, could be consistent with the higher amounts of MDMA measured in pills.

New synthetic drugs in addictovigilance.

New substances, also known as "designer drugs" or "legal highs" are increasingly available to drug users. Two hundred and fifteen hitherto unlisted substances have been notified by European Union member states since 2005. These synthetic drugs, which have been developed to side-step the legislation on drugs, are analogues or derivatives of existing drugs and medications. The availability of these "legal highs", sold on Internet under various denominations such as bath salt, plant fertilizer, chemical not intended for human use, or spice, is unlimited. The effects felt by users vary, and the substances may be stimulant, entactogenic, hallucinogenic, psychedelic or dissociative. The pharmacological targets also vary, and may be either the increase of extracellular levels of neurotransmitters via different mechanisms (reuptake inhibition, stimulation of intracellular release) or else fixation on specific receptors. Several chemical classes, themselves divided into sub-classes, are involved: phenethylamines, tryptamines, piperazines, cathinones, cannabinoids etc. The toxicity of the main members of these categories is increasingly well known, the most deleterious being behavioural effects, physical manifestations, and cardiovascular consequences. However, small variations in their chemical structure can generate effects that are quantitatively different, thus enhancing their toxicity or addictive potential, and much remains to be achieved in terms of knowledge about these new drugs. These substances are indeed present on the French territory, as shown by data provided by the Observatoire Français des Drogues et Toxicomanies, and notifications by the French Addictovigilance network. Screening in clinical toxicology laboratories is not widespread, since these molecules are not detected by the standard screening tests, so that there is probably an under-estimation of the use of these new drugs. The legislation on these substances changes regularly, with more and more countries classifying them as "narcotics" or illegal psychotropic drugs so as to restrict their use, applying a generic classification when possible.

National reflection on organs-on-chip for drug development: New regulatory challenges.

Organs-on-chip (OoC) are innovative and promising in vitro models, particularly in the process of developing new drugs, to improve predictivity of preclinical studies in humans. However, a lack of regulatory consensus on acceptance criteria and standards around these technologies currently hinders their adoption and implementation by end-users. A reflection has been conducted at the National Agency for Medicines and Health products safety (ANSM) in order to address this issue, which has gained momentum at the international level in recent years. If the subject of OoC is of international interest, France is also in the process of structuring an OoC network, in order to best support the emergence of this new technological innovation. Focusing on liver-on-a-chip, the authors drafted a first list of regulatory requirements to help standardize these devices and their use. Technological and biological relevance of liver-on-a-chip was also evaluated, in comparison with current in vitro and in vivo models, based on the available literature. The authors offer an analysis of the current scientific and regulatory situation, highlighting the key regulatory issues for the future.

Radiolabelling of 1,4-disubstituted 3-[18F]fluoropiperidines and its application to new radiotracers for NR2B NMDA receptor visualization.

In order to develop a novel and useful building block for the development of radiotracers for positron emission tomography (PET), we studied the radiolabelling of 1,4-disubstituted 3-[(18)F]fluoropiperidines. Indeed, 3-fluoropiperidine became a useful building block in medicinal chemistry for the pharmacomodulation of piperidine-containing compounds. The radiofluorination was studied on substituted piperidines with electron-donating and electron-withdrawing N-substituents. In the instance of electron-donating N-substituents such as benzyl or butyl, configuration retention and satisfactory fluoride-18 incorporation yields up to 80% were observed. In the case of electron-withdrawing N-substituents leading to carbamate or amide functions, the incorporation yields depend on the 4-susbtitutent (2 to 63%). The radiolabelling of this building block was applied to the automated radiosynthesis of NR2B NMDA receptor antagonists and effected by a commercially available radiochemistry module. The in vivo evaluation of three radiotracers demonstrated minimal brain uptakes incompatible with the imaging of NR2B NMDA receptors in the living brain. Nevertheless, moderate radiometabolism was observed and, in particular, no radiodefluorination was observed which demonstrates the stability of the 3-position of the fluorine-18 atom. In conclusion, the 1,4-disubstituted 3-[(18)F]fluoropiperidine moiety could be of value in the development of other radiotracers for PET even if the evaluation of the NR2B NMDA receptor antagonists failed to demonstrate satisfactory properties for PET imaging of this receptor.

[Use of synthetic substances in France and in Europe]. / Usages de substances de synthèse en France et en Europe.

This paper aims to present the main information presented at the 9th Meeting about addictovigilance in 2016 by four healthcare professionals and addiction experts on the issue of new psychoactive substance use. A new psychoactive substance (NPS) is defined as a narcotic or psychotropic drug, in pure form or in preparation, that is not controlled by the United Nations drug conventions, but which may pose a public health threat comparable to that posed by substances listed in these conventions. The emergence of NPS consumption is a worldwide concern. Although NPS are less consumed than established drugs, there has been a sharp increase in their use over the last few years, notably of synthetic cathinones, synthetic cannabinoids and, more recently, synthetic opioids. The latter in particular are involved in deaths in Europe. However, "established" drugs (MDMA [methylenedioxymethamphetamine], amphetamines, LSD, methamphetamine) are far from being dethroned by the more recent substances: they are considered "a safe bet" already "tried and tested" by many consumers over the years. MDMA, in particular, also known as ecstasy, which has been used as a recreational drug since the 1990s, saw its consumption decrease until 2010, and then increase again, especially in higher amounts; inexpensive and easily accessible, it is increasingly associated with emergency admissions or deaths in France. The perpetual appearance of new substances on the drug market is obligating to improve knowledge on these products, particularly by focusing on their analytical identification, and also by monitoring their use and harms.

[Therapeutic drug monitoring of clobazam]. / Suivi thérapeutique pharmacologique du clobazam.

Clobazam is a 1,5 benzodiazepine available in France since 1975, used in add-on with the other anticonvulsant drugs in the treatment of refractory epilepsies of child and adult and for the treatment of anxiety of adult. It is mainly metabolized in desmethylclobazam, or norclobazam, active metabolite, present in a concentration approximately eight times superior to that of the parent drug, but with an activity of the order of 20 to 40% of that of clobazam. Elimination half-life of clobazam is of 18 h while that of norclobazam is from 40 to 50 h. There is a large interindividual variability in the plasma concentrations. Furthermore, clobazam being prescribed in add-on with the other anticonvulsant drugs in resistant epilepsies, concentration-effect relationship is difficult to bring to light, since, in many studies, the patients who did not answer received the highest doses. Adverse reactions are moderated, appearing more often for the highest concentrations; also the phenomenon of tolerance seems more frequent in high concentrations. However, because of the kinetic interactions, a dosage of clobazam and norclobazam can be useful in certain cases. There is no validated therapeutic range, but the usual concentrations are in the range of 100-300 microg/L for the parent drug and about ten times more for the metabolite. The level of proof of the interest of the Therapeutic Drug Monitoring for this molecule is estimated in: rather useless.

[Not Available]. / Suivi thérapeutique pharmacologique du clobazam.

Clobazam is a 1,5 benzodiazepine available in France since 1975, used in add-on with the other anticonvulsant drugs in the treatment of refractory epilepsies of child and adult and for the treatment of anxiety of adult. It is mainly metabolized in desmethylclobazam, or norclobazam, active metabolite, present in a concentration approximately eight times superior to that of the parent drug, but with an activity of the order of 20 to 40% of that of clobazam. Elimination half-life of clobazam is of 18 h while that of norclobazam is from 40 to 50 h. There is a large interindividual variability in the plasma concentrations. Furthermore, clobazam being prescribed in add-on with the other anticonvulsant drugs in resistant epilepsies, concentration-effect relationship is difficult to bring to light, since, in many studies, the patients who did not answer received the highest doses. Adverse reactions are moderated, appearing more often for the highest concentrations; also the phenomenon of tolerance seems more frequent in high concentrations. However, because of the kinetic interactions, a dosage of clobazam and norclobazam can be useful in certain cases. There is no validated therapeutic range, but the usual concentrations are in the range of 100-300 µg/L for the parent drug and about ten times more for the metabolite. The level of proof of the interest of the Therapeutic Drug Monitoring for this molecule is estimated in: rather useless.

[Therapeutic drug monitoring of clonazepam]. / Suivi thérapeutique pharmacologique du clonazépam.

Clonazepam is a 1-4 benzodiazepine mainly used to treat epilepsy and epileptiform convulsion state. Rapidly absorbed after oral administration, it is widely distributed in the organism and is extensively converted in metabolites, poorly or not active, eliminated mainly in urine (70%) and feces. Elimination half-life is long, around 40 h. In adult and child, several studies showed a concentration-effect relation. Meanwhile, a large inter-individual variability in the dose-concentration relation was observed. A 15-50 microg/L range of clonazepam blood concentrations appears to be retained as an acceptable target to control a majority of epileptic seizures. The Therapeutic Drug Monitoring (TDM) of clonazepam can be considered as possibly useful in case of association with CYP450 inducers or inhibitors, suspicion of poor observance, or toxicity signs.

[Not Available]. / Suivi thérapeutique pharmacologique du clonazépam.

Clonazepam is a 1-4 benzodiazepine mainly used to treat epilepsy and epileptiform convulsion state. Rapidly absorbed after oral administration, it is widely distributed in the organism and is extensively converted in metabolites, poorly or not active, eliminated mainly in urine (70%) and feces. Elimination half-life is long, around 40 h. In adult and child, several studies showed a concentration-effect relation. Meanwhile, a large inter-individual variability in the dose-concentration relation was observed. A 15-50 µg/L range of clonazepam blood concentrations appears to be retained as an acceptable target to control a majority of epileptic seizures. The Therapeutic Drug Monitoring (TDM) of clonazepam can be considered as possibly useful in case of association with CYP450 inducers or inhibitors, suspicion of poor observance, or toxicity signs.

[Mephedrone: a designer drug of recent use in France]. / La méphédrone : une designer drug d'usage récent en France.

Designer drugs are currently marketed as substitutes for stimulant drugs as cocaine, amphetamine, MDMA...Unlike compounds listed as narcotics, these new substances are deliberately synthesized to avoid anti-drug laws. Among them, mephedrone (4-methylmethcatinone) that belongs to cathinone family, has been recently introduced in France. Users report positive euphoric and entactogenic effects. They also describe negative effects such as increased dependence towards the drug itself and larger craving for tobacco and alcohol. The numerous and various described adverse effects include psychoactive, digestive, cardiovascular... effects. Some fatality cases have been reported in scientific literature or in press and attributed to mephedrone often in association with other substances. Mephedrone has been listed as narcotic in several European countries and more recently in France.

[Comparison between analytic and anamnestic data about drug consumption among opiate addicts with substitutes therapy. A feasibility study]. / Comparaison des données analytiques et anamnestiques des consommations de drogues et psychotropes chez des usagers d'opiacés en traitement de substitution. Etude de faisabilité

In this feasibility study of an observational nature, we used the protocol 'AnalyTox-Op' to compare analytical data with anamnestic reports gathered from specialized drug addiction treatment centers. These data were collected from 32 drug addicts who were patients undergoing treatment with addictive drug substitutes or prescribed psychotropic drugs. Urine toxicology screens were performed using immunological methods followed by confirmation with more specific techniques, i.e. gas chromatography coupled with mass spectrometry (GC-MS) and liquid chromatography with diode array detection (HPLC-DB). While complete agreement between patient reports of drug consumption (obtained from a questionnaire) and analytical data was only observed in 13 out of the 32 cases, a very good concordance was seen with opiate substitutes (88% with methadone and high-dosage buprenorphine, combined) and legally prescribed psychotropic drugs. Of note, however, was the omission of illicit drug use in patient questionnaires, especially with cocaine (22%) and recreational opiates (22%), causing discordance in the comparison. This study is currently being expanded to include a large number of participants across the country with the aim of obtaining data under homogeneous conditions, verifying the discordance we found and determining its significance.

Radiosynthesis and ex vivo evaluation of [11C]-SIB-1553A as a PET radiotracer for beta4 selective subtype nicotinic acetylcholine receptor.

[11C]-SIB-1553A ((+/-)-4-[2-((N-[11C]-methyl)-2-pyrrolidinyl)ethyl]thiophenol) was labelled with carbon-11 (t1/2=20.4 min) and evaluated in vivo as potential radiotracer for noninvasive assessment of the beta4 subunit nicotinic acetylcholine neurotransmission system with positron emission tomography (PET). The labelling precursor was obtained within five steps from N-Boc-prolinal in 45-56% overall yields. The radiosynthesis of [11C]-SIB-1553A was achieved by a selective N-[11C]-methylation in 32 min with a radiochemical purity greater than 97%, 7.5-30 GBq/micromol of specific radioactivity and 55-65% radiochemical yield (decay corrected, based on [11C]methyl iodide). The ex vivo pharmacological profile of [11C]-SIB-1553A was evaluated in rats with biodistribution studies in organs and in brain structures by autoradiography. The radiotracer uptake in the brain reached 0.49 %ID/g at 10 min and no brain radiometabolite was detected 40 min after intravenous injection. The quantification of radioactivity in various cerebral structures indicated a significantly higher radioactivity level at 15 min than at 30 min. Among the beta4 nAChR subunit-rich structures studied in the rat brain, only the thalamus at 15 and 30 min and the hippocampus at 30 min showed significantly higher uptake. Moreover, competition studies performed with SIB-1553A (15 min before the radiotracer injection) revealed only a low specific binding estimated to 7% of the total binding at 15 min and 13% at 30 min.

[11C]-MeJDTic: a novel radioligand for kappa-opioid receptor positron emission tomography imaging.

INTRODUCTION: Radiopharmaceuticals that can bind selectively the kappa-opioid receptor may present opportunities for staging clinical brain disorders and evaluating the efficiency of new therapies related to stroke, neurodegenerative diseases or opiate addiction. The N-methylated derivative of JDTic (named MeJDTic), which has been recently described as a potent and selective antagonist of kappa-opioid receptor in vitro, was labeled with carbon-11 and evaluated for in vivo imaging the kappa-opioid receptor in mice. METHODS: [(11)C]-MeJDTic was prepared by methylation of JDTic with [(11)C]-methyl triflate. The binding of [(11)C]-MeJDTic to kappa-opioid receptor was investigated ex vivo by biodistribution and competition studies using nonfasted male CD1 mice. RESULTS: [(11)C]-MeJDTic exhibited a high and rapid distribution in peripheral organs. The uptake was maximal in lung where the kappa receptor is largely expressed. [(11)C]-MeJDTic rapidly crossed the blood-brain barrier and accumulated in the brain regions of interest (hypothalamus). The parent ligand remained the major radioactive compound in brain during the experiment. Chase studies with U50,488 (a kappa referring agonist), morphine (a mu agonist) and naltrindole (a delta antagonist) demonstrated that this uptake was the result of specific binding to the kappa-opioid receptor. CONCLUSION: These findings suggested that [(11)C]-MeJDTic appeared to be a promising selective "lead" radioligand for kappa-opioid receptor PET imaging.

Pharmacokinetics of 300 mg/d Intraperitoneal Daptomycin: New Insight from the DaptoDP Study.

The DaptoDP (NCT 2012-005699-33) study aimed to evaluate the pharmacokinetic parameters of daptomycin (DAP) in peritoneal dialysis-related peritonitis (PDRP) patients following intraperitoneal (IP) administration. The authors have already reported the findings on the 200-mg dosing and present here the follow-up results of the 300-mg dosing. The primary endpoint was a dialysate concentration of DAP above the effective concentration in situ during 6 hours of dwell time i.e., 16 mg/L. Secondary endpoints were to avoid the toxic threshold of 120 mg/L DAP and to be above 16 mg/L DAP for 2 hours in plasma. Pharmacokinetic parameters were evaluated on days 1 and 5. Safety data were evaluated on days 1 to 14 based on clinical and biological parameters. Daptomycin was administered in Nutrineal during 6 hours of dwell time for 14 days plus the usual antibiotic therapy in a separate dwell. Because the 200-mg dosing objectives were not reached, a higher DAP dose of 300 mg was tested in the next 3 patients. Effective dialysate and plasma concentrations were achieved at the 300-mg DAP dose with the plasma concentration well below the toxic threshold, even at steady state, during which the accumulation factor never exceeded 3. The optimal DAP dose of 300 mg daily by the IP route, as determined by the pharmacokinetic data, needs to be clinically confirmed prior to routine use. The peritoneal bioavailability of DAP supports using the IP route as an alternative to the intravenous route for peritonitis and systemic infections.

Pharmacokinetics of Intraperitoneal Daptomycin in Patients with Peritoneal Dialysis-Related Peritonitis.

♦ BACKGROUND: Antibiotics are preferentially delivered via the peritoneal route to treat peritoneal dialysis-related peritonitis (PDRP) to ensure that maximal concentrations are delivered to the site of infection. Our study focused on the pharmacokinetics of daptomycin (DAP) administered via the intraperitoneal (IP) route in patients with PDRP. ♦ METHODS: According to the DaptoDP protocol (Clinical Trial No. 2012-005699-33), IP DAP was administered daily, i.e., during the 6-h Nutrineal (Baxter Healthcare Corporation, Deerfield, IL, USA) dwell time period, for 14 days, in addition to administration of the antibiotics used for the usual care of patients with PDRP. The plasma and IP levels of DAP were measured on days 1 and 5. The tested dose was 200 mg/day. The principal endpoint was the dialysate concentration after 6 hours of dwell time > 16 mg/L (corresponding to 4 x minimum inhibitory concentration [MIC] for E. faecalis). ♦ RESULTS: Three participants were evaluated. On day 5, the IP concentrations after 6 hours of dwell time were between 6.3 and 23.4 mg/L, and the peak plasma concentrations were between 13.0 and 15.3 mg/L. ♦ CONCLUSION: The results suggest that 200 mg/day is very likely sufficient for the treatment of PDRP by Staphylococci or Streptococci whereas it could be insufficient to treat PRDP by Enterococci. The good peritoneal bioavailability of DAP was quantitatively established, suggesting that IP administration could also be used as an alternate route for patients with damaged venous access. No DAP accumulation that could lead to toxic concentrations after repeated administration is expected, even in anuric patients. The protocol will further continue to assess whether a higher dose achieves the pharmacokinetic objectives.

Competitive displacement binding assay on rat brain sections and using a beta-imager: application to mu-opioid ligands.

A new approach of competitive displacement binding assay using brain sections and a beta-imager is presented to estimate binding parameters such as affinity and selectivity of new compounds or to characterize receptor families or subtypes of receptors in small brain regions. This method includes a preliminary saturation assay intended to define the optimal concentration of displaceable radio-labeled ligand followed by the determination of displacement constants (IC(50) and K(i)) in cerebral regions rich in studied receptor. The technique application was demonstrated in seven rat brain structures, using displacement of the selective tritiated mu-opioid ligand [(3)H]-DAMGO by six opioid ligands: a specific agonist (DAMGO), less specific agonists (morphine, remifentanil), a non-specific antagonist with good affinity for mu receptors (naloxone) and ligands specific of other opioid subtypes (naltrindole, U50.488). Radioactivity counts were collected during 48 h. The assay-validation was performed by measuring intra- and inter-assay variation on determinations and by comparing presently obtained K(i) values with data from recognised methodologies. Both prove the accuracy of the proposed method.

Interactions of buprenorphine and dipotassium clorazepate on anxiety and memory functions in the mouse.

Buprenorphine, a partial mu-receptor agonist widely substituted for heroin in the treatment of addiction, is often misused in combination with benzodiazepines. Improved hedonic properties may result, but only at the cost of increased buprenorphine toxicity. In order to elucidate the appeal of the benzodiazepine-buprenorphine combination, the present study looked at its neuropsycho-pharmacological effects on various emotional and cognitive parameters in the mouse. On the basis of previous dose-response studies, the regimen used was buprenorphine 0.3mg/kg, s.c. plus dipotassium clorazepate 1, 4 and 16 mg/kg, i.p. Anxiety-like behaviour was assessed using the black and white test box, and memory processes were examined via the spontaneous alternation paradigm in the Y-maze, and passive avoidance tests. Spontaneous locomotor activity was also evaluated. High doses of clorazepate impaired buprenorphine-induced hyperactivity and anxiogenic-like effects. They also increased buprenorphine-induced spontaneous alternation impairment, but did not modify its impact on long-term memory processes. These results suggest that the positive reinforcement experienced with the buprenorphine-benzodiazepine combination may be attributable, at least in part, to an increase in buprenorphine's sedative effect associated with a decrease in anxiogenicity.