Substance use disorder of equimolar oxygen-nitrous oxide mixture in French sickle-cell patients: results of the PHEDRE study.

BACKGROUND: In many countries, nitrous oxide is used in a gas mixture (EMONO) for short-term analgesia. Cases of addiction, with significant misuse, have been reported in hospitalized patients. Patients suffering from sickle cell disease (SCD) could represent a high-risk population for substance use disorder (SUD) due to their significant pain crisis and repeated use of EMONO. The objective of the PHEDRE study was to assess the prevalence of SUD for EMONO in French SCD patients. RESULTS: A total of 993 patients were included. Among 339 EMONO consumers, only 38 (11%) had a SUD, with very few criteria, corresponding mainly to a mild SUD due to a use higher than expected (in quantity or duration) and relational tensions with the care teams. Almost all patients (99.7%) were looking for an analgesic effect, but 68% of patients were also looking for other effects. The independent risks factors associated with at least one SUD criterion were: the feeling of effects different from the expected therapeutic effects of EMONO, at least one hospitalization for vaso occlusive crisis in the past 12 months and the presence of a SUD for at least one other analgesic drug. CONCLUSIONS: The use of EMONO was not problematic for the majority of patients. Manifestations of SUD that led to tensions with healthcare teams should alert and lead to an evaluation, to distinguish a true addiction from a pseudoaddiction which may be linked to an insufficient analgesic treatment related to an underestimation of pain in SCD patients. TRIAL REGISTRATION: Clinical Trials, NCT02580565. Registered 16 October 2015, https://clinicaltrials.gov/.

Characterization of antipsychotic utilization before clozapine initiation for individuals with schizophrenia: an innovative visualization of trajectories using French National Health Insurance data.

AIMS: Despite recommendations to initiate clozapine after two unsuccessful trials of antipsychotics, clozapine is underprescribed and initiated too late. The aim of this study was to describe different antipsychotic treatment sequences in the 36 months before the initiation of clozapine and to characterize clusters of treatment trajectories. METHODS: Using the French National Health Insurance database, a historical cohort study of the population in an area in western France was performed. The data from all new users of clozapine with a diagnosis of schizophrenia or schizoaffective disorder in the period of 2017-2018 were evaluated. All outpatient reimbursements for antipsychotics during the 36 months before clozapine initiation were analysed. Successive reimbursements for identical treatments were grouped into treatment trials (TTs), and different trajectories were clustered using a state sequence analysis. RESULTS: The results showed 1191 TTs for 287 individuals. The mean number of TTs per individual was 3.2. Risperidone, aripiprazole and haloperidol were the main treatments delivered. The frequencies of antipsychotics used differed between monotherapies and combination therapies. A three-cluster typology was identified: one cluster (n = 133) of 'less treated' younger individuals with fewer TTs and shorter TT durations; a second cluster (n = 53) of 'more treated' individuals with higher numbers of TTs and combinations of antipsychotics; and a third cluster (n = 103) of 'treatment-stable' older individuals with longer TT durations. CONCLUSIONS: The results indicate that the median number of TTs during the 36 months before clozapine prescription was higher than the two recommended. The different trajectories were associated with individual characteristics and treatment differences, suggesting that additional studies of clinical parameters are needed to understand barriers to clozapine prescription.

First results of the French OCTOPUS survey among festival attendees: a latent class analysis.

BACKGROUND: Illicit substance use has constantly evolved over the years, particularly in the party scene. Monitoring these changes is essential to adapt harm reduction strategies. The OCTOPUS survey was implemented to enhance knowledge on drug use at music festivals. The objective of the work presented here was to describe drug use and to characterize profiles of substance use in music festival attendees. METHODS: OCTOPUS was a cross-sectional survey carried out during 13 various music festivals (dub, eclectic and electronic music) in the Loire-Atlantique department (France) from July 2017 to July 2018. Participants were festival attendees. Data were collected by trained research staff using a face-to-face structured interview. We analysed the use of illicit drugs in the last 12 months to describe the prevalence of use and to characterize the profile of substance use using a latent class analysis. RESULTS: In total, 383 festival attendees were included. Of 314 (82%) participants who reported drug use, the most reported drugs were cannabis, ecstasy/MDMA and cocaine. We identified two profiles of drug use: (i) a "no/low polysubstance use" profile mainly characterized by the use of "classic" stimulants (ecstasy/MDMA, cocaine) and (ii) "moderate/extensive polysubstance use", with high probabilities of "classic" stimulants use and especially other drugs reported: speed, ketamine, new psychoactive substances (NPSs). CONCLUSION: We observed frequent polysubstance use in festival attendees. Harm reduction should be targeted at the increased risk of toxicity linked to polysubstance use, and the reduction in harm caused by particular drugs (ketamine, NPS, speed) could be further strengthened.

Did the New French Regulation of Zolpidem Decrease the Problematic Consumption of Zolpidem? A Field Study among Users.

Background: The French national drug regulatory authority stated, in 2017, that a secured prescription pad must be used for zolpidem prescriptions. This study aimed to evaluate the evolution of the problematic consumption of zolpidem at the individual level since the new regulation. Methods: Two nationwide populations of at-risk users of zolpidem were recruited: one in general practitioner (GP) offices and one in specialized care centers dedicated to drug dependence (SCDDs). Participants were asked about their zolpidem consumption before and after the regulation change. The primary outcome was the evolution of problematic zolpidem consumption, as defined by at least one of the following criteria: overconsumption, fraudulent ways of obtaining, effects sought other than hypnotic, and modes of administration other than oral. Results: A total of 243 participants were included: 125 from GP offices and 118 from SCDDs. In the GP population, the prevalence of patients who were identified as problematic consumers decreased from 24.8% to 20.8% (p = 0.593), whereas the prevalence decreased from 73.7% to 51.7% in the SCDD population (p < 0.001). The most prevalent criteria for problematic status were overconsumption and fraudulent ways. Conclusions: The new French regulation of zolpidem had different impacts among two different populations of at-risk zolpidem consumers.

Perception of the Regulatory Change for Zolpidem Prescription by French General Practitioners and Its Relation to Prescription Behavior.

Background: To "limit the risk of abuse and misuse" and "encourage correct usage", the French drug regulatory authority stated that­from April 2017­zolpidem prescription must be performed on a secured prescription pad. This national study aims to evaluate the perception of general practitioners (GPs) towards this new regulation and its link with prescription strategies. Methods: We conducted structured interviews of GPs. Data were collected about GPs' perception of the measure and therapeutic strategies towards zolpidem. The primary outcome was the description of the GPs' strategy of prescription, based on the perception towards the new regulation for zolpidem. Results: For 206 GPs, the new regulation was mainly perceived as helpful (61%) and as a difficulty (55%). Other perceptions were the awareness of the risks of zolpidem (18%), awareness of the risks of hypnotics (13%), and nothing changed (5%). Four clusters of GPs were identified. In the clusters with the perception as a difficulty (only or associated with helpful), the GPs who applied the strategy "no modification" for >50% of their patients were more frequently compared to awareness and helpful only clusters (60.8%; 42.9%; 20.4%; 26.7%) (p < 0.001). Conclusions: We highlighted an association between the perception of the new regulation of zolpidem prescription by GPs and a strategy of prescription.

Did the pattern of use of zolpidem change since the enforcement of a new prescription rule? A latent class analysis using the French health insurance database.

BACKGROUND: In recent years, zolpidem has been the subject of numerous reports of misuse, abuse and dependence. In view of these risks, the French drug agency decreed the implementation of secure prescription pads in April, 2017. The objective of this study was to characterize the impact of this regulatory change on the patterns of zolpidem use. RESEARCH DESIGN AND METHODS: We included patients with at least one reimbursement for zolpidem before and/or after the regulatory change using a sample of the French health insurance database. For each period, we identified profiles of users using a latent class analysis (LCA). RESULTS: In total, 15,550 zolpidem users were identified before the measure and 8,301 after the measure. We identified the same three profiles of zolpidem users before and after the measure: non-problematic users (the most prevalent), users whose drug prescriptions suggest psychiatric disorder and potential problematic users. The profile of potential problematic users was similar after the regulatory change but represented a lower absolute number of patients. CONCLUSION: In conclusion, the regulatory change had a positive impact on the patterns of zolpidem use, but the impact should be reevaluated, because withdrawal can take a long time, especially in long-term users. TRIAL REGISTRATION: The study was registered at www.clinicaltrials.gov under the reference number NCT03584542.

Potential drug-drug interactions when managing status epilepticus patients in intensive care: A cohort study.

AIMS: The risk for drug-drug interactions (DDIs) associated with antiseizure drugs (ASDs) used to manage status epilepticus (SE) patients in the intensive care unit (ICU) has been poorly investigated. We aimed to quantify and describe those potential DDIs and determine SE patient risk profiles. METHODS: We conducted an observational bi-centric cohort study including all SE patients admitted to the ICU in the period 2016-2020. RESULTS: Overall, 431 SE patients were included and 5504 potential DDIs were identified including 1772 DDIs (33%) between ASDs, 2610 DDIs (47%) between ASDs and previous usual treatments (PUTs), and 1067 DDIs (20%) between ASDs and ICU treatments (ICUTs). DDIs were moderate (n = 4871), major (n = 562) or severe (n = 16). All patients exhibited potential DDIs, which were major-to-severe DDIs in 47% of the cases. DDIs were pharmacokinetic (n = 1972, 36%), mostly involving cytochrome P450 modulators, and pharmacodynamic (n = 3477, 64%), mainly leading to increased sedation. ASD/PUT DDIs were the most frequent and severe. Age, PUT and ASD drug numbers and length of ICU stay were significantly associated with increased DDI number. We identified four SE patient profiles with different DDI risks and outcomes including (1) epileptic or brain trauma patients, (2) withdrawal syndrome patients, (3) older patients with comorbidities and (4) self-poisoned patients with psychiatric disorders and/or past epilepsy. CONCLUSION: SE patients are subject to potential DDIs between ASDs, ASD/PUT and ASD/ICUT. Major-to-severe DDIs mostly occur between ASDs and PUTs. Physicians should pay attention to SE patient characteristics and history to limit DDI numbers and prevent their consequences.

Poppers Use and High Methaemoglobinaemia: 'Dangerous Liaisons'.

Poppers are legal and largely used in France despite severe side effects, such as methaemoglobinaemia (MetHbia). Our work aimed to assess the prevalence of poppers consumers among patients with a MetHbia higher than or equal to 5% in French university hospitals and its evolution before and after the legalization of poppers in France. We conducted a national multicentre observational retrospective study. All patients for whom at least one MetHbia measurement was performed from 2012 to 2017 in university hospitals where the French addictovigilance network (FAN) is implanted were included. For each MetHbia measurement exceeding or equal to 5%, a return to the clinical file was made by the FAN to assess poppers consumption. We calculated the prevalence of MetHbia exceeding or equal to 5% and 25% and the prevalence of poppers consumption before and after the legalization. A total of 239 (0.14%) patients had a MetHbia level exceeding or equal to 5% with 25 (10.46%) cases of poppers consumption. Poppers consumption represented 68.4% (13 out of 19) of cases with MetHbia greater than or equal to 25%. Poppers consumption among patients with MetHbia exceeding or equal to 5% increased after the legalization from 4.76% to 11.67% (prevalence ratio PR = 2.45, 95% CI = [0.98-8.37], p-value = 0.190). The proportion of patients with a MetHbia level of 25% or more increased after the legalization from 4.76% to 8.63% (PR = 1.81, 95% CI = [0.68-6.82], p-value = 0.374). The use of poppers is very frequently reported by patients with MetHbia greater than or equal to 25%.

What about regular hematological monitoring during clozapine treatment? A compliance analysis using the French health insurance database.

BACKGROUND: The inherent risk of agranulocytosis associated with clozapine requires the realization of weekly white blood cell monitoring (WBCM) during the 18 first weeks of treatment. The aim of this study was to assess the compliance with WBCM during clozapine initiation for schizophrenia and Parkinson's disease (PD) subjects. RESEARCH DESIGN AND METHOD: The analysis was conducted using SNDS data on a cohort of new users of clozapine in 2018. We analyzed all reimbursements for WBCM from 2 weeks before the index date to 18 weeks after (optimal monitoring during hospitalization was assumed). The primary outcome was the proportion of good realization of WBCM according to different thresholds of completion (70%; 80%; 90%). Descriptive and comparative analyses with chi-squared test or Student's t-test were performed. RESULTS: Two hundred and ninety-six subjects were included. Rates of patients with WBCM realization over 70%, 80%, and 90% of WBCM expected were, respectively, 78.1%, 70.0%, and 56.9% for subjects with schizophrenia and 71.3%, 63.2%, and 47.8% for PD subjects. Only hospitalization during the follow-up period for schizophrenia subjects was significantly associated with good WBCM realization. CONCLUSIONS: We observed rather good results for compliance with clozapine initial monitoring. Other studies are needed to confirm our results.

Descriptive analysis of sickle cell patients living in France: The PHEDRE cross-sectional study.

BACKGROUND: Sickle cell disease (SCD) induces chronic haemolytic anaemia and intermittent vaso-occlusion that results in tissue ischaemia causing acute, severe pain episodes that can lead to frequent hospitalizations. These consequences can have repercussions on family, social, school and/or professional life. Here, we present some of the results of the PHEDRE study (Pharmacodépendance Et DREpanocytose-drug dependence and sickle-cell disease), which is the largest study of patients with SCD in France. This paper intends to describe characteristics of the French SCD population. We also aimed to assess the impact of the disease on the lives of patients using objective and subjective variables. METHODS: The PHEDRE study was a national multicentric observational study. Adults, adolescents and children with a confirmed SCD diagnosis were included in the study by their referring doctor. Then, they were interviewed by phone about their socioeconomic status, about the impact of the disease on their lives and about their analgesic and psychoactive drug use. RESULTS: The study population consisted of 872 patients (28% were minors). Seventy-two percent of adults were active, and all minors were in school. Many patients presented criteria of severe SCD. Seventy-five percent were homozygous SS, 15% were double heterozygotes SC and 8% were heterozygotes Sßthal, 87% received specific treatment, 58% were hospitalized at least once for vaso-occlusive crisis in the past 12 months, and the number of analgesic drugs taken averaged 3.8. Seventy-five percent of patients reported academic or professional consequences related to their SCD, and 52% reported social consequences. CONCLUSIONS: The impact of SCD on patients' lives can be significant, nevertheless their social integration seems to be maintained. We highlighted respect of recommendations regarding analgesic treatments and only a few patients used tobacco, alcohol or cannabis. TRIAL REGISTRATION: Clinical Trials, NCT02580565; https://clinicaltrials.gov/ Registered 16 October 2015.

Change in the regulatory framework for zolpidem: What is the impact on the landscape of the prescription of sedative medications? The French national ZORRO study.

AIMS: In recent years, zolpidem has been the subject of numerous reports of misuse, abuse and dependence. In view of these risks, the French drug agency (ANSM) decreed in April 2017 the implementation of secure prescription pads. The objective of this study was to evaluate the impact of this regulatory measure on the prescription of zolpidem and other sedative medications (zopiclone, benzodiazepines and antihistamines) in long-term users of zolpidem and associated factors. METHODS: We performed a historical cohort study using data from the Generalist Sample of Beneficiaries (EGB). All patients aged over 18 years old who were long-term users (at least 3 months) before the measure were enacted. We analysed the reimbursement trajectories of zolpidem, zopiclone, benzodiazepines and antihistamines (hydroxyzine and alimemazine) up to 2 years after the measure using a state sequence analysis. RESULTS: Overall, 2502 patients were analysed. A four-cluster typology was identified: continuation of zolpidem (n = 1044, 42%), discontinuation of sedative medications (n = 766, 31%), change to zopiclone (n = 537, 21%) and change to hypnotic benzodiazepines (n = 155, 6%). The most frequently prescribed hypnotic benzodiazepine was lormetazepam. We identified age, sex, treatment for psychiatric or addictive disorder and volume of zolpidem use before the measure as factors associated with different reimbursement trajectories after the regulatory change. CONCLUSION: The regulatory change for zolpidem prescriptions reduced exposure to zolpidem among long-term users and also had a broad impact on prescriptions of other sedative medications. Switching to other medications that also present a potential risk of abuse or dependence should be carefully monitored.

Benzodiazepine withdrawal in older people: what is the prevalence, what are the signs, and which patients?

PURPOSE: Benzodiazepines (BZDs) and related drugs (Z-drugs) are mainly taken chronically, and older people are much more likely to take them on a chronic basis despite recommendations. Withdrawal symptoms could be an obstacle to stopping BZD/Z-drug administration. The main objective of this study is to estimate the prevalence of withdrawal symptoms in patients aged 65 years and older who have experience a stop of BZD/Z-drug. The secondary objectives are to describe the withdrawal symptoms and identify factors associated. METHOD: This ancillary study was based on a national observational study in patients with chronic BZD/Z-drug consumption. Patients who made at least one BZD/Z-drug stop experience were selected. Withdrawal symptoms are described, and a logistic regression was carried out to identify the variables most associated with withdrawal symptoms. RESULTS: In total, 697 patients were selected: 78% experienced at least one withdrawal symptom after a stop administering BZDs or Z-drugs; most of the withdrawal symptoms were psychological disorders. CONCLUSION: Our study identifies a specific population experiencing withdrawal symptoms and who cannot stop administering BZD/Z-drug. We assume that withdrawal symptoms in patients with chronic use play an essential role in the nonstop use of BZD/Z-drugs.

Assessment of drug-drug interaction in an elderly human immunodeficiency virus population: Comparison of 3 expert databases.

AIMS: Polypharmacy increase the risk of drug-drug interactions (DDIs) in the elderly population living with human immunodeficiency virus (HIV). Several expert databases can be used to evaluate DDIs. The aim of the study was to describe actual DDIs between antiretroviral drugs and comedications in an elderly population and to compare grading of the DDIs in 3 databases. METHODS: All treatments of HIV-infected subjects aged 65 years and older were collected in 6 French HIV centres. Summary of Product Characteristic (SPC), French DDI Thesaurus (THES), and Liverpool HIV DDI website (LIV) were used to define each DDI and specific grade. DDIs were classified in yellow flag interaction (undefined grade in SPC and THES or potential weak interaction in LIV), amber flag interaction (to be considered/precaution of use in SPC and THES and potential interaction in LIV) and red flag interaction (not recommended/contraindication in SPC and THES and do not administer/contraindication in LIV). RESULTS: Among 239 subjects included, 60 (25.1%) had at least 1 DDI for a total of 126 DDIs: 23/126 red flag DDIs were identified in 17 patients. All these 23 DDIs were identified in LIV. THES and SPC missed 6 and 1 red flag DDIs, respectively. Seven of 23 red flag DDIs were identified in the 3 databases concomitantly. CONCLUSION: Polypharmacy is frequent in this elderly HIV population leading to DDI in a quarter of the subjects. The discrepancies between databases can be explained by differences in analysis methods. A consensus between databases would be helpful for clinicians.

Are Seniors Dependent on Benzodiazepines? A National Clinical Survey of Substance Use Disorder.

Benzodiazepines and Z-drugs, zolpidem and zopiclone, (BZD/Z) are used longer than recommended in the elderly population. However, to date, very few attempts have been made to evaluate dependence on BDZ/Z among the elderly population. We conducted a national multicentric observational prospective study aimed at evaluating the prevalence of and risk factors for dependence among elderly adults. Patients aged 65 or older who were treated with BZD/Z for at least 3 months were evaluated through clinical interviews that conformed to official Diagnostic and Statistical Manual of Mental Disorders (DSM) dependence criteria. Among the 1,024 patients included in the survey, 442 of 976 (45.3%) met the dependence criteria. In the multivariate logistic regression model, dependent patients were categorized as follows: younger (odds ratio (OR) = 0.97), living mostly alone (OR = 1.45), showing psychiatric problems (OR = 2.22), having additional treatments (other than BZD/Z; OR = 1.37), having long-lasting treatment (OR = 1.04), exhibiting significant relationship difficulties (OR = 1.96), committing transgressional behaviors to procure BZD/Z (OR = 2.70), and wanting to stop their consumption of BZD/Z (OR = 7.60). A latent class analysis, which was applied to sort out subgroups within dependent patients, identified two profiles according to the prevalence of dependence items: profile 1 (73%), "withdrawal syndrome when BZD/Z is stopped" (100%) and "previous unsuccessful attempts to stop consumption" (82%); and profile 2 (27%), "tolerance" (76%) and "intake in larger amounts or over a longer period than intended" (86%). BZD/Z dependence is frequent in the elderly population, and among dependent patients, we found two profiles corresponding to positive and negative conditioning of the psychoactive effects of BZD/Z. This study is registered as NCT01920581.

CYP1A2 and tobacco interaction: a major pharmacokinetic challenge during smoking cessation.

Smoking cessation is underestimated in terms of drug interactions. Abrupt smoking cessation is common in cases of emergency hospitalization and restrictions of movement. Tobacco is a known cytochrome P450 1A2 (CYP1A2) inducer, its consumption and withdrawal can lead to major pharmacokinetic drug interactions. Nevertheless, references do exist, but may have different results between them. The objective of our work was to establish the broadest and most consensual list as possible of CYP1A2 substrates treatments and propose a pharmacological approach. We searched the widest possible list of CYP1A2 substrates based on various international references. We compared the references and defined probability and reliability scores of our results to sort the substances based on the scores. For the 245 substances identified as CYP1A2 substrates, we focused on the 63 CYP1A2 substrates with both probability and reliability scores >50%. Our work establishes adaptive pharmacological approaches for the management of patients initiating smoking cessation which must be integrated into the management of smoking cessation. Pharmacologists can now adopt adaptive pharmacological approaches to complement patient-specific clinical information about smoking cessation by considering pharmacokinetic risk. This work establishes an unprecedented list. It should guide in the care of patients initiating smoking cessation to prevent pharmacokinetic drug interactions.

Development and validation of a dosing nomogram for amoxicillin in infective endocarditis.

BACKGROUND: Amoxicillin is the first-line treatment for streptococcal or enterococcal infective endocarditis (IE) with a dose regimen adapted to weight. OBJECTIVES: Covariates influencing pharmacokinetics (PK) of amoxicillin were identified in order to develop a dosing nomogram based on identified covariates for individual adaptation. PATIENTS AND METHODS: Patients treated with amoxicillin administered by continuous infusion for IE were included retrospectively. The population PK analysis was performed using the Pmetrics package for R (NPAG algorithm). Influence of weight, ideal weight, height, BMI, body surface area, glomerular filtration rate adapted to the body surface area and calculated by the CKD-EPI method (mL/min), additional ceftriaxone treatment and serum protein level on amoxicillin PK was tested. A nomogram was then developed to determine the daily dose needed to achieve a steady-state free plasma concentration above 4× MIC, 100% of the time, without exceeding a total plasma concentration of 80 mg/L. RESULTS: A total of 160 patients were included. Population PK analysis was performed on 540 amoxicillin plasma concentrations. A two-compartment model best described amoxicillin PK and the glomerular filtration rate covariate significantly improved the model when included in the calculation of the elimination constant Ke. CONCLUSIONS: This work allowed the development of a dosing nomogram that can help to increase achievement of the PK/pharmacodynamic targets in IE treated with amoxicillin.

Do older people know why they take benzodiazepines? A national French cross-sectional survey of long-term consumers.

OBJECTIVES: Benzodiazepines and non-benzodiazepine hypnotics (or Z-drugs) (BZD/Z) are widely prescribed for older patients despite major side effects and risks when chronically used. The patient's understanding of the treatment is one of the keys to good adherence. The purpose of the study was to assess the knowledge of BZD/Z treatment among older people who were taking BZD/Z for the long term by studying the concordance between the declared reason for taking BZD/Z and its indication. METHODS: This was a cross-sectional, pharmacoepidemiologic ancillary of a national study. Data were collected through a semi-structured interview. All patients from the main study were included. "Good knowledge" was considered when patients gave an indication for each BZD/Z that was similar to its marketing authorisation. Univariate and multivariate analyses were carried out to adequately determine profiles and characterise associations. RESULTS: More than half of the patients (61.6%) had a good knowledge regarding their treatment. The presence of a psychiatric disorder, a mean duration of BZD/Z use of less than 120 months, a desire to stop treatment, educational status and number and type of BZD/Z used were significantly associated (P < .05) with good knowledge. In the multivariate analysis, only a psychiatric disorder, educational status and taking at least one hypnotic drug were associated with good knowledge. CONCLUSIONS: At the time of shared medical decision, it appears essential to improve the knowledge of the treatment by the patient. The rate of patients with good knowledge of their BZD/Z treatment remains low and even lower than what was previously found in the literature for other drug classes. In contrast to patients with good knowledge, these data highlight the characteristics of patients with poor knowledge of their BZD/Z treatment, which may allow populations at risk to be targeted and enable education measures to be strengthened.

Prevalence of zolpidem use in France halved after secure prescription pads implementation in 2017: A SNDS database nested cohort study.

Our objective was to quantify the impact on the use of zolpidem of the obligation implemented in France in 2017 to use secure prescription pads to prescribe it. We conducted a cohort study within the French SNDS healthcare database. Patients aged over 18 years of age were considered for inclusion. The number of prevalent users and incident episodes of zolpidem use were compared before the change in law (July 1, 2016 to January 1, 2017) and after (July 1, 2017 to January 1, 2018). A prevalent user was a patient who has been reimbursed for zolpidem at least once. An incident episode of zolpidem use was defined by a first administration of zolpidem without any prior administration within the previous six months. Regarding prevalence of zolpidem users, we observed a decrease from 2.79% (CI95%:2.75-2.83) to 1.48% (1.44-1.51), with a number of patients who stopped taking it after the change in law being approximately 4.3 times higher than the number of patients who started. We observed a negative association between the post-law change period (OR = 0.52 (0.51-0.53)) and the probability of receiving zolpidem, adjusting for sex, aging, low income and chronic disease. We observed a decrease from 183 treatment episodes per 100,000 insured months on average to 79 episodes per 100,000 insured months, with an incidence rate ratio (IRR) equal to 0.43 (0.38-0.49). The use of secure prescription pads seems to have reduced the exposure of the French population to zolpidem.

Simultaneous determination of eight ß-lactam antibiotics in human plasma and cerebrospinal fluid by liquid chromatography coupled to tandem mass spectrometry.

Therapeutic drug monitoring of ß-lactam antibiotics is increasingly used for dose optimization in the individual patient to increase efficacy and reduce the risk of toxicity. The objective of this work is to develop and validate a fast and reliable method using liquid chromatography coupled to tandem mass spectrometric detection to quantify simultaneously amoxicillin, cloxacillin, cefazolin, cefotaxime, ceftazidime, cefepime, meropenem and piperacillin in plasma and cerebrospinal fluid (CSF). Sample clean-up included protein precipitation with acetonitrile followed by evaporation of the supernatant and reconstitution of the residue with mobile phase solvents. Eight deuterated ß-lactam antibiotics were used as internal standards. Chromatographic separation was performed on a C18 column (50 mm x 2.1 mm) using a binary gradient elution of water and acetonitrile both containing 0.1% (v/v) formic acid. The total run time was 8 min. The method was then used to perform therapeutic drug monitoring on 2221 patient plasma samples. 32 CSF samples were also analyzed. This method, with its simple sample preparation provides sensitive, accurate and precise quantification of the plasma and cerebrospinal fluid concentration of ß-lactam antibiotics and can be used for therapeutic drug monitoring.