Individual variations in motives for nicotine self-administration in male rats: evidence in support for a precision psychopharmacology.

The significant heterogeneity in smoking behavior among smokers, coupled with the inconsistent efficacy of approved smoking cessation therapies, supports the presence of individual variations in the mechanisms underlying smoking. This emphasizes the need to shift from standardized to personalized smoking cessation therapies. However, informed precision medicine demands precision fundamental research. Tobacco smoking is influenced and sustained by diverse psychopharmacological interactions between nicotine and environmental stimuli. In the classical experimental rodent model for studying tobacco dependence, namely intravenous self-administration of nicotine, seeking behavior is reinforced by the combined delivery of nicotine and a discrete cue (nicotine+cue). Whether self-administration behavior is driven by the same psychopharmacological mechanisms across individual rats remains unknown and unexplored. To address this, we employed behavioral pharmacology and unbiased cluster analysis to investigate individual differences in the mechanisms supporting classical intravenous nicotine self-administration (0.04 mg/kg/infusion) in male outbred Sprague-Dawley rats. Our analysis identified two clusters: one subset of rats sought nicotine primarily for its reinforcing effects, while the second subset sought nicotine to enhance the reinforcing effects of the discrete cue. Varenicline (1 mg/kg i.p.) reduced seeking behavior in the former group, whereas it tended to increase in the latter group. Crucially, despite this fundamental qualitative difference revealed by behavioral manipulation, the two clusters exhibited quantitatively identical nicotine+cue self-administration behavior. The traditional application of rodent models to study the reinforcing and addictive effects of nicotine may mask individual variability in the underlying motivational mechanisms. Accounting for this variability could significantly enhance the predictive validity of translational research.

Interpretation of hair and nails findings in an infant death case related to maternal addiction to tramadol.

An 11-month-old boy was found dead. Autopsy findings (cyanosis and polyvisceral congestion) and blood tramadol (TR) concentration of 6240 µg/L were consistent with an acute TR intoxication. In this poisoning situation, owing to the mother's statements (TR addiction leading to daily TR-orange juice mixture preparation accidentally used for the baby bottle preparation by the mother's partner), and the question of possible previous TR administrations to the infant, hair and/or nails (infant, mother, partner, 6-year-old sister) analysis was performed. Hair (2-cm-long hair segments from proximal [S1] to distal [S3]) and nails concentrations (pg/mg; nd: not detected) were as follows: Infant (hair: TR 1420 [S1], 1622 [S2], 2736 [S3]; O-DMT 16-38; N-DMT 34-100 [TR in significant quantities in the hair decontamination bath]-toenails: TR 584; O-DMT 8; N-DMT 15), mother (hair: TR 2340 [S1], 2150 [S2], 2500 [S3]; O-DMT 704-1170; N-DMT 827-1360), mother's partner (fingernails: TR 72; O-DMT nd; N-DMT nd) and sister (hair: TR 261 [S1], 524 [S2]; O-DMT 15 [S1], 16 [S2]; N-DMT 20 [S1], 38 [S2]). Metabolite ratio (infant and sister hair) was comparable to those observed in hair of pharmaceutical industry employees manufacturing tramadol. TR in washing baths, low observed nail concentrations (infant and partner) confirm (i) TR-related mother's addiction and (ii) external contamination issues (TR in sweat of the child at the time of death and in living environment) to explain the infant's keratinized samples results. This case report illustrates the interest of analyzing keratinized matrices of the whole family in such a situation.

2-MeOPP positive hair result in case of urapidil treatment.

The metabolism of urapidil to 2-MeOPP induces the risk of detection of 2-MeOPP in biological samples (blood, urine and hair) in case of urapidil treatment. This is supported by two case reports and an in vitro study of urapidil metabolism.

Trends in the Pharmaceutical Design of New Psychoactive Substances Detected in Oral Fluid OF Drivers Around a Music Festival in South-West France: Comparison 2019/2017.

OBJECTIVE: New psychoactive substance use (NPS) is a reality in France, including among drivers. This work aims (i) to report the pharmaceutical design of NPS detected in oral fluid (OF) from drivers initially screened for drugs around a music festival in 2019 and (ii) to compare obtained results with those of a previous similar study carried out in 2017 in the same situation (and the same music festival) and according to the same methodology. METHODS: OF specimens were recovered from the user devices of the salivary immunochemical tests used by the police during the controls carried out at the entering and leaving the festival. These OF were analyzed using liquid chromatography coupled with tandem mass spectrometry and high-resolution mass spectrometry methods using mass spectra libraries of approximately 1700 substances, including (in 2020) more than 650 NPS and metabolites. RESULTS: NPS was detected in 14 out of the 265 collected OF specimens. Ten NPS were identified (number of identification): APINACA (1), AB-Chminaca (1), 5F-AMB (1), 5F-PB-22 (5), 2C-D (1), methoxetamine (2), ketamine (1), x-CMC (1), 4-MEC (2), ethylone (2). The prevalence of NPS detection in OF (5.2%) is in the same order as the observed one in 2017 (6.8%), but these results are marked by the majority and increasing proportion of synthetic cannabinoids (47% of identified NPS in 2019 vs. 25% in 2017), an increase also in the proportion of cathinone derivatives (29% in 2019 vs. 6% in 2017), and a decrease in cyclohexanones (17% in 2019 vs. 43% in 2017). CONCLUSION: These pharmaceutical design trends (2019 vs. 2017) observed in a population of drivers around a music festival seem to reflect those that can be seen in more general populations in France, with probably a rise in the consumption of synthetic cannabinoids.

Long-Lasting Analgesia With Transdermal Fentanyl: A New Approach in Rat Neonatal Research.

Background: With advances in neonatal care, management of prolonged pain in newborns is a daily concern. In addition to ethical considerations, pain in early life would have long-term effects and consequences. However, its treatment remains inadequate. It was therefore important to develop an experimental model of long-lasting analgesia for neonatal research. Materials and Methods: Experiments were performed in six groups of rats with transdermal fentanyl 0, 3, 12, 50, 100, or 200 µg/kg/h from second postnatal day (P2) until weaning. Assessment of analgesia was carried out at P21, with behavioral scores (ranging from 0 to 3) using a 4% formalin test. Plasma levels of fentanyl were determined by UPLC/TQD at P22. Growth rate was investigated. Results: Fentanyl 100 and 200 µg/kg/h reduced scores of formalin-evoked behavioral pain. They increased time spent in pain score 0 (8 min 55 s and 6 min 34 s versus 23 s in controls) as in low pain scores 1 and 2, and decreased time in the most severe pain score 3 (19 min 56 s and 17 min 39 s versus 44 min 15 s). Fentanylemia increased in a dose-dependent manner from 50 µg/kg/h (2.36 ± 0.64 ng/ml) to 200 µg/kg/h (8.66 ± 1.80 ng/ml). Concerning growth, no difference was observed except weaker growth from P17 to P22 with 200 µg/kg/h. Clinically, we noticed no visible side effect from 3 to 100 µg/kg/h. Concomitantly, 200 µg/kg/h was responsible for ophthalmological side effects with appearance of corneal bilateral clouding in 90% pups. No difference was observed between male and female rats. Conclusion: Altogether, results indicate that transdermal fentanyl 100 µg/kg/h is an efficient therapeutic for long-lasting analgesia in lactating pups. This new model provides a useful tool for protection and welfare, and future opportunity for studying long-term health consequences of sustainable neonatal analgesia.

Long-Term Analgesia following a Single Application of Fentanyl Transdermal Solution in Pigs.

INTRODUCTION: In animal research, obtaining efficient and constant pain control is regulatory but challenging. The gold standard pain management consists of opioid analgesic administration, such as buprenorphine or fentanyl extended-release patches. However, as in all drugs with a short half-life time, repeated buprenorphine administrations are needed, leading to multiple injections that affect the research protocol. On the other hand, fentanyl patch efficacy is discussed in some species. These elements highlight the need of an optimal formulation of analgesic drugs for laboratory animals. In this study, we investigated how Recuvyra®, a fentanyl transdermal solution (FTS), validated in dog perioperative pain management, could provide sustained analgesia after a single topical administration in pigs in a surgical context. METHODS: A total of 11 minipigs were used in this study. As a preliminary experiment, two different doses were tested as a single application on five pigs: two pigs at full dose (2.6 mg/kg) and three pigs at half dose (1.3 mg/kg). Plasma fentanyl dosages were performed during 4 consecutive days, using liquid chromatography with tandem mass spectrometry detection. The efficacy of FTS was then evaluated in a perioperative period. Six minipigs benefited from a surgical intervention comprising a laparotomy. The FTS was blotted on the skin in a single application 20 min before the surgical incision and plasma fentanyl dosages, clinical examination (body weight, food intake, heart rate, and body temperature) and pain assessment were performed for 7 consecutive days. RESULTS: During the preliminary experiment, all fentanyl concentrations reached the minimum effective concentration (MEC) extrapolated in pigs (fentanylemia ≥0.2 ng/mL) throughout the 4 days. The half dose was chosen for the next step of the study. After the surgical intervention, all plasma fentanyl concentrations remained above the MEC up to 7 days post administration. Pig clinical examinations and pain evaluations showed efficient and constant pain control at the half dose, and few adverse events were observed. DISCUSSION AND CONCLUSION: This study confirms the pharmacological and clinical efficacy of FTS at 1.3 mg/kg in pigs throughout at least 7 postoperative days following laparotomy. The clinical analgesic effect of FTS appears more efficient and well-tolerated than the one observed with repeated injections of buprenorphine. This analgesic drug formulation could be universally used in animal research to provide optimal perioperative pain management and long-term analgesia.

Exhumation of a Methamphetamine Body-Packer: Pitfalls of Hair Result Interpretation.

Carrying out toxicological investigations in biological samples (e.g. hair) collected from extensively decomposed bodies and even more interpretation of subsequently obtained results is challenging, even more in some particular circumstances of death. In order to illustrate these pitfalls, we report the case of the exhumation of a methamphetamine body-packer. Autopsy examination of a 41-year-old man, one year after his burial, revealed the presence of 44 green pellets (7 out of 44 were torn) along all the gastrointestinal tract. A 6-cm long dark hair strand and pellets were sampled for toxicological analyses. Large toxicological screenings were applied to hair and pellets using both LC-MS/MS and LC-HRMS. Intact pellets contained around 10 g of methamphetamine (MA) with a purity ranging from 29 to 35 %. Positive hair results were amiodarone (4.12 ng/mg), desethylamiodarone (5.29 ng/mg) and methamphetamine (7.63 ng/mg). Methamphetamine pellets in gastrointestinal tract were consistent with the autopsy conclusion, i.e. fatal intoxication due to in corpore pellet rupture in a body-packer (the victim was initially deemed to have died from heart failure). In the absence of available data in the literature, amiodarone and metabolite presence in hair could putatively be the consequence of a chronic treatment. Methamphetamine hair concentration was similar to those observed in regular consumers. However, interpreting this hair result is challenging due to (i) the possibility of contamination by sweat at the time of death, and (ii) the probable contamination by putrefaction fluids. This latter hypothesis (artifactual contamination during the post-mortem period) is highly supported by high concentration of methamphetamine in decontamination bath, and even more by the absence of the major methamphetamine metabolite (amphetamine) in hair. As a conclusion, in this particular situation, the hair analysis result (presence of MA and concomitant absence of amphetamine) is in agreement with the previously-established cause of death.

Putatively lethal ingestion of isopropyl alcohol-related case: interpretation of post mortem isopropyl alcohol and acetone concentrations remains challenging.

Isopropyl alcohol, or propan-2-ol (IPA), is found in numerous chemicals including alcohol-based hand rubs whose use has been recently widely extended to the general population since the onset of the COVID-19 pandemic. This widespread of IPA use could potentially, but not necessarily, be responsible for an increase in IPA poisoning cases (e.g., in alcoholics and/or for suicide attempt, even more in a lockdown situation). Forensic identification of IPA-related fatalities remains challenging as IPA post mortem detection can also result from antemortem or post mortem production, or post mortem contamination. In order to illustrate this issue, we report the case of a 33-year-old man found dead with a bottle of pure IPA liquid close to him. Toxicological positive results only consisted in IPA (464, 260, 465 and 991 mg/L) and acetone (1560, 2340, 3040 and 1360 mg/L) in blood, vitreous humour, urine and bile, respectively (determinations using headspace gas chromatography with flame ionization detection). These IPA absolute concentrations and IPA-to-acetone ratios appear inferior to those usually reported in the literature (higher than 1000 mg/L and 1.1, respectively) in IPA poisoning cases. In conclusion, this death can be cautiously regarded as an IPA ingestion-related fatality in the hypothesis of a survival time which have promoted IPA metabolism to acetone: this hypothesis is supported by the putative limited IPA-ingested dose. This report emphasizes the fact that post mortem IPA and acetone concentration interpretation involves to take account of (i) results in multiple biological specimens, (ii) complete case history, and (iii) a search of possible IPA presence at the scene of death.

Pitfalls of toxicological investigations in hair, bones, and nails in extensively decomposed bodies: illustration with two cases.

It is difficult to carry out toxicological investigations in biological samples collected from extensively decomposed bodies and to interpret obtained results as several pitfalls should be considered: redistribution phenomena, degradation of xenobiotics during the postmortem period, contamination by putrefaction fluids, and external contamination. This work aims to present two cases in order to illustrate and discuss these difficulties in this tricky situation. Case#1: the body of a 30-year-old woman was found in a wooded area (1 month after she has been reported missing by her family): hair and a femur section were sampled. Case#2: the decomposed corpse of a 52-year-old man was found in a ditch: hair and nails were sampled. After decontamination steps, toxicological investigations were performed using liquid chromatography with high-resolution mass spectrometry and tandem mass spectrometry detection methods. In case#1, the same drugs or metabolites (benzodiazepines, propranolol, tramadol, acetaminophen, paroxetine, and oxetorone) were detected in hair and in bone specimens. This result combination strongly suggests intakes close to the time of death for three of them (oxazepam, lormetazepam, and propranolol). In case#2, results of toxicological investigations in hair and nails [(hair/nail concentration in ng/mg) nordiazepam (1.12/1.06), oxazepam (0.113/0.042), zolpidem (0.211/< 0.01), hydroxyzine (0.362/< 0.01), and cetirizine (0.872/1.110)] were both consistent with several drug intakes but were not contributory to cause of death determination. In case of positive toxicological results in biological samples collected from extensively decomposed bodies (such as hair, bones, or nails), it is challenging to determine the time, and even more, the level of the dose of exposure(s).

Pyroglutamide-Based P2X7 Receptor Antagonists Targeting Inflammatory Bowel Disease.

This report deals with the design, the synthesis, and the pharmacological evaluation of pyroglutamide-based P2X7 antagonists. A dozen were shown to possess improved properties, among which inhibition of YO-PRO-1/TO-PRO-3 uptake and IL1ß release upon BzATP activation of the receptor and dampening signs of DSS-induced colitis on mice, in comparison with reference antagonist GSK1370319A. Docking study and biological evaluation of synthesized compounds has highlighted new SAR, and low toxicity profiles of pyroglutamides herein described are clues for the finding of a usable h-P2X7 antagonist drug. Such a drug would raise the hope for a cure to many P2X7-dependent pathologies, including inflammatory, neurological, and immune diseases.

[Phosphatidylethanol blood analysis]. / Dosage sanguin du phosphatidyléthanol.

This article aims to place the phosphatidylethanol (PEth) blood test in the detection area of ethanol consumption causing alcohol-related disorders, to present the current methods of analysis, data on interpretation, some practical applications and the prospects of use of this biomarker. PEth is a minor metabolite of ethanol. Among nearly 50 PEth counterparts, PEth 16:0/18:1 is the most abundant. The interest that PEth brings compared to other biomarkers is the extended window of detection of ethanol consumptions. Indeed, it has a blood elimination half-life of approximately 5 days, which offers estimated alcohol consumption for a 21 to 28 days period. Thus, the detection of alcohol use disorders and withdrawal monitoring (systematically combined with urinary ethylglucuronide) in addictology and in liver pre- and post-transplantation are today its main routine applications. Nevertheless, additional data are still necessary to improve the interpretation of measured concentrations and to reach a consensus on interpretation cut-offs of blood PEth concentrations.

New psychoactive substances in oral fluid of drivers around a music festival in south-west France in 2017.

Driving under the influence of drugs (DUID) is a worldwide problem with potentially major forensic and life-threatening consequences. Although it is obvious that new psychoactive substances (NPS) could lead to impaireddriving, the prevalence of NPS use in a DUID context is unknown as the applied roadside screening tests for drugs of abuse (DOA) are not adapted for NPS detection. This works aims to tested oral fluid (OF) specimens for NPS in French drivers circulating around two music festivals (Artsenik 2017 and Garorock 2017) in order to assess the prevalence of consumption and the kind of used NPS in this particular population. OF samples consisted in dried saliva spots obtained from used Drugwipe-5S® tests (after a positive or negative roadside screening test for DOA). These OF were analyzed using a liquid chromatography coupled with tandem mass spectrometry or high-resolution mass spectrometry method. NPS were detected in 17 out of the 229 OF collected specimens (7.4%). Eleven various NPS were identified (number of identification): 5F-AKB48 (2), MAM2201 (1), JWH122 (1), 4F-PVP (1), 3- or 4-MMC (2), fluoromethamphetamine (1), ketamine (3), MXE (3), methoxyketamine (1), 6-APB (2) and 25C-NBOMe (1). There is an apparent effect of the music festival proximity on the prevalence of NPS in OF from this controlled driver population compared to that of 140 controlled drivers from Northern France analyzed in the same period (7.4% versus 3%). The variety of used NPS appears to be increasing (e.g. large proportion of cyclohexanones). In addition, 5% of drivers initially roadside-tested negative for DOA were in fact driving after NPS use in this specific population. From a forensic perspective, these results confirm the reality of driving after NPS use in French drivers, notably in those driving to or from a music festival.

Use of hair testing to determine methadone exposure in pediatric deaths.

A case of death attributed to methadone acute poisoning in an infant aged 11 months is reported. A sudden infant death syndrome (SIDS) was suspected, whereas a traumatic cause of death was excluded regarding autopsy findings. Specimens were submitted to a large toxicological analysis, which included ethanol measurement by HS-GC-FID, a targeted screening for drugs of abuse and various prescription drug classes followed by quantification using UPLC-MS/MS methods. Methadone and its metabolite (EDDP) were detected in all the tested fluids, as well as in hair, with a blood concentration of methadone considered as lethal for children (73 ng/mL). The cause of death was determined to be acute "methadone poisoning", and the manner of death was "accidental". A discussion of the case circumstances, the difficulties with the interpretation of toxicological findings in children (blood concentration and hair testing), and the origin of exposure are discussed.

Near-fatal tramadol cardiotoxicity in a CYP2D6 ultrarapid metabolizer.

BACKGROUND: Tramadol is a synthetic, centrally acting analgesic for the treatment of moderate to severe pain. The marketed tramadol is a racemic mixture containing 50% (+)tramadol and 50% (-)tramadol and is mainly metabolized to O-desmethyltramadol (M1) by the cytochrome P450 CYP2D6. Tramadol is generally considered to be devoid of any serious adverse effects of traditional opioid receptor agonists, such as respiratory depression and drug dependence. CASE REPORT: A 22-year-old Caucasian female patient was admitted to our ICU in refractory cardiac arrest requiring extracorporeal membrane oxygenation. This aggressive support allowed resolution of multi-organ dysfunction syndrome. Repeated blood analyses using liquid chromatography-tandem mass spectrometry confirmed high concentrations of both tramadol and its main metabolite O-desmethyltramadol. Genotyping of CYP2D6 revealed the patient to be heterozygous for a duplicated wild-type allele, predictive of a CYP2D6 ultrarapid metabolizer (UM) phenotype, confirmed by calculation of the tramadol/M1 (MR1) metabolic ratio at all time points. DISCUSSION: We here report a case of near-fatal isolated tramadol cardiotoxicity. Because of the inhibition of norepinephrine reuptake, excessive blood epinephrine levels in this CYP2D6R UM patient following excessive tramadol ingestion could explain the observed strong myocardial stunning. This patient admitted intermittent tramadol consumption to gain a "high" sensation. In patients with excessive morphinomimetic effects, levels of tramadol and its main metabolite M1could be measured, ideally combined with CYP2D6 genotyping, to identify individuals at risk of tramadol-related cardiotoxicity. Tramadol treatment could be optimized in these at-risk individuals, consequently improving patient outcome and safety.