Risk of relapse after natalizumab withdrawal: Results from the French TYSEDMUS cohort.

OBJECTIVE: To assess disease activity within 12 months after natalizumab (NZ) discontinuation in a large French postmarketing cohort. METHODS: In France, patients exposed at least once to NZ were included in the TYSEDMUS observational and multicenter cohort, part of the French NZ Risk Management Plan. Clinical disease activity during the year following NZ discontinuation was assessed in this cohort. Time to first relapse after NZ stop was analyzed using Kaplan-Meier method and potentially associated factors were studied using a multivariate Cox model. RESULTS: Out of the 4,055 patients with multiple sclerosis (MS) included in TYSEDMUS, 1,253 discontinued NZ and 715 of them had relevant data for our study. The probability of relapse within the year after NZ stop was estimated at 45% (95% confidence interval 0.41-0.49). CONCLUSIONS: This large and systematic survey of patients with MS after NZ withdrawal allows quantifying the risk of increased disease activity following treatment discontinuation. This study provides large-scale, multicenter, systematic data after NZ cessation in real-life settings.

Guillain-Barré syndrome and adjuvanted pandemic influenza A (H1N1) 2009 vaccines: a multinational self-controlled case series in Europe.

BACKGROUND: The risk of Guillain-Barré syndrome (GBS) following the United States' 1976 swine flu vaccination campaign in the USA led to enhanced active surveillance during the pandemic influenza (A(H1N1)pdm09) immunization campaign. This study aimed to estimate the risk of GBS following influenza A(H1N1)pdm09 vaccination. METHODS: A self-controlled case series (SCCS) analysis was performed in Denmark, Finland, France, Netherlands, Norway, Sweden, and the United Kingdom. Information was collected according to a common protocol and standardised procedures. Cases classified at levels 1-4a of the Brighton Collaboration case definition were included. The risk window was 42 days starting the day after vaccination. Conditional Poisson regression and pooled random effects models estimated adjusted relative incidences (RI). Pseudo likelihood and vaccinated-only methods addressed the potential contraindication for vaccination following GBS. RESULTS: Three hundred and three (303) GBS and Miller Fisher syndrome cases were included. Ninety-nine (99) were exposed to A(H1N1)pdm09 vaccination, which was most frequently adjuvanted (Pandemrix and Focetria). The unadjusted pooled RI for A(H1N1)pdm09 vaccination and GBS was 3.5 (95% Confidence Interval (CI): 2.2-5.5), based on all countries. This lowered to 2.0 (95% CI: 1.2-3.1) after adjustment for calendartime and to 1.9 (95% CI: 1.1-3.2) when we accounted for contra-indications. In a subset (Netherlands, Norway, and United Kingdom) we further adjusted for other confounders and there the RI decreased from 1.7 (adjusted for calendar month) to 1.4 (95% CI: 0.7-2.8), which is the main finding. CONCLUSION: This study illustrates the potential of conducting European collaborative vaccine safety studies. The main, fully adjusted analysis, showed that the RI of GBS was not significantly elevated after influenza A(H1N1)pdm09 vaccination (RI = 1.4 (95% CI: 0.7-2.8). Based on the upper limits of the pooled estimate we can rule out with 95% certainty that the number of excess GBS cases after influenza A(H1N1)pdm09 vaccination would be more than 3 per million vaccinated.

First French experience of ADR reporting by patients after a mass immunization campaign with Influenza A (H1N1) pandemic vaccines: a comparison of reports submitted by patients and healthcare professionals.

BACKGROUND: Available data concerning the contribution of patient adverse drug reaction (ADR) reporting in practice are scarce. Few studies have compared patients' reports with reports from healthcare professionals (HCPs). During the 2009-10 mass immunization campaign with A (H1N1)v2009 pandemic influenza vaccines, a reinforced pharmacovigilance plan was introduced in France according to European Medicines Agency recommendations. For the first time, patients were offered the opportunity to report suspected ADRs to pandemic vaccines directly to regional pharmacovigilance centres. OBJECTIVE: The aim of the study was to compare the characteristics of patient and HCP ADR reports in order to assess the qualitative and quantitative contribution of patient reporting to the French Pharmacovigilance System. METHODS: All spontaneous ADRs registered into the French Pharmacovigilance Database from 21 October 2009 to 15 June 2010, in which either one of the most frequently administered pandemic vaccines (i.e. Panenza® or Pandemrix®) was involved, were analysed. ADRs were classified as 'serious', 'medically serious' and 'non-serious'. This study focused on 'serious' and 'medically serious' ADRs. An ADR was ranked as 'medically serious' when it required medical intervention or hospitalization within less than 24 hours. In each level of seriousness, frequency of 'unlabelled' ADRs, ADRs of 'special interest', imputability scores and category of ADRs according to Medical Dictionary for Regulatory Activitives (MedDRA®) primary System Organ Class were compared between patient and professional reports. RESULTS: Among the 4746 reports received during the study period, 1006 (21.2%) originated from patients. HCPs reported significantly more 'medically serious' or 'serious' ADRs than patients (15.1% [565/3740] vs 8.4% [85/1006], respectively; p < 0.001). No difference was found in 'unlabelled, serious' ADRs between patients and HCPs (56.5% [n = 13] vs 56.7% [n = 136], respectively). CONCLUSIONS: In this first French experience of formal patient participation to ADR reporting, patient contribution to the total number of ADRs reached 21.2%. This study revealed no major qualitative difference between patient and HCP reports. ADR profiles reported by patients appeared to be consistent with those from professionals. Further investigations are necessary to assess the intrinsic quality of notification forms coming from non-professional reporters. However, this study is of particular interest in the context of publication of the first governmental decree that will formally integrate patient participation to the current French ADR reporting scheme.

Road traffic crashes and prescribed methadone and buprenorphine: a French registry-based case-control study.

BACKGROUND: Opioids have been shown to impair psychomotor and cognitive functioning in healthy volunteers with no history of opioid abuse. Few or no significant effects have been found in opioid-dependant patients in experimental or driving simulation studies. The risk of road traffic crash among patients under buprenorphine or methadone has not been subject to epidemiological investigation so far. The objective was to investigate the association between the risk of being responsible for a road traffic crash and the use of buprenorphine and methadone. METHODS: Data from three French national databases were extracted and matched: the national health care insurance database, police reports, and the national police database of injurious crashes. Case-control analysis comparing responsible versus non responsible drivers was conducted. RESULTS: 72,685 drivers involved in an injurious crash in France over the July 2005-May 2008 period, were identified by their national health care number. The 196 drivers exposed to buprenorphine or methadone on the day of crash were young, essentially males, with an important co-consumption of other substances (alcohol and benzodiazepines). Injured drivers exposed to buprenorphine or methadone on the day of crash, had an increased risk of being responsible for the crash (odds ratio (OR)=2.02, 95% confidence interval (CI): 1.40 and 2.91). CONCLUSIONS: Users of methadone and buprenorphine were at increased risk of being responsible for injurious road traffic crashes. The increased risk could be explained by the combined effect of risky behaviors and treatments.

[National Campaign of Vaccination against the flu A (H1N1)v: National Follow-up of Pharmacovigilance]. / Campagne nationale de vaccination contre la grippe A (H1N1)v : suivi national de pharmacovigilance.

OBJECTIVES: The present study was performed to evaluate safety data collected by the French Network of Pharmacovigilance centres network, from October 21, 2009 to June 15, 2010. METHODS: French Health Authorities (Afssaps [Agence française de sécurité sanitaire des produits de santé]) heightened awareness to extensive notifications with online health practitioners' reports and patients' reports via the Regional Centre concerned. RESULTS: During the campaign, 4.1 millions doses of Pandemrix(®) and 1.6 million doses of Panenza(®) were administered. Following Pandemrix(®), 4 183 adverse effects (AEs) were reported including 193 "serious" AEs. Concerning Panenza(®), 591 AEs were reported including 70 "serious" AE. The most frequently reported "serious" AEs were neurological for both Pandemrix(®) (38.9%, mainly isolated ascending paresthesia without any other neurological symptom and complication) and Panenza(®) (28.9%). Febrile convulsions were the most common neurological AEs with Panenza(®) in children. All reported deaths (n = 22) described causes other than recent A(H1N1)v vaccination. No causal relationship was established between these AEs and vaccination. Among AEs of "special" interest, 13 reports of confirmed GBS and 15 reports of demyelinating disorders were notified. No report of narcolepsy was made during the study period. CONCLUSION: For both vaccines, neurological AEs (isolated ascending paresthesia with Pandemrix(®) and febrile convulsions with Panenza(®)) were among the most frequently reported "serious" AEs. Despite limits of this survey based on spontaneous reporting, the study did not detect any safety signals, at least with an 8-month follow-up.

Role of the post-marketing authorisation studies in drug risk surveillance: specifications and methodologies.

Studies conducted after the marketing authorisation with the objective of identification, characterization or quantification of one or more risks (called PASS "Post-Authorisation Safety Studies"), have been strengthened in the past years with the implementation of the concept of risk management plans (RMPs), established in 2005 in the European regulatory framework and recently amended as part of the community revision. These safety studies, interventional or not, are related to a marketed drug, whether or not the drug is used within the market authorisation conditions. Apart from these safety studies, other studies whose primary objective is not risk assessment, including assessment of efficacy, description of prescription data and use in real life, pharmacokinetics, public health impact ... can complete available safety data.The Giens Round Table examined PASS from the risk management plans of a sample of marketing authorisation holders (participants to the Round Table) and identified the main characteristics of proposed actions. Concerning the specifications and the choice of methodology, only a general outline has been sketched in view of the complexity and diversity of drug risks situations.

[Drugs and heat wave: SIRIUS, a multicentric case-control study in patients older than 65 years during 2007 summer in France]. / Médicaments et chaleur: étude SIRIUS cas-témoins multicentrique chez les sujets de plus de 65 ans durant l'été 2007 en France.

OBJECTIVE: To evaluate in real conditions the role of drugs in heat-related adverse effects. METHODS: We performed a multicentric case-control study in 3 university hospitals in France, including 36 cases (patients older than 65 years hospitalized with hyperthermia or dehydration between 1st July and 31st August 2007) and 51 controls. We compared drugs and changes in drug dosage according to the values of renal function. RESULTS: At inclusion, clearance creatinine was available for only 12 patients (mean = 31.6 ml/min), and three-fold higher in controls (p < 0.001). Cases took more drugs than controls (4.3 vs. 3.9; p < 0.001), particularly neuroleptic drugs (3.6% vs. 0.5%; p = 0.007). CONCLUSION: Despite its small size, our study shows that patients suffering from dehydration in summer are those with more severe renal impairment, taking more drugs (particularly neuroleptics). This pilot work could allow to improve methodology of further studies on drugs during heat waves.

The impact of medicinal drugs on traffic safety: a systematic review of epidemiological studies.

PURPOSE: To evaluate the quality of epidemiological research into effects of medicinal drugs on traffic safety and the current knowledge in this area. DATA SOURCES: The bibliographic search was done in Medline electronic database using the keywords: ((accident* or crash*) and traffic and drug*) leading to 1141 references. Additional references were retrieved from the Safetylit website and the reference lists of selected studies. Original articles published in English or French, between 1 April 1979 and 31 July 2008, were considered for inclusion. We excluded descriptive studies, studies limited to alcohol or illicit drug involvement and investigations of injuries other than from traffic crashes. Studies based on laboratory tests, driving simulators or on-the-road driving tests were also excluded. Eligible studies had to evaluate the causal relationship between the use of medicinal drugs and the risk of traffic crashes. Study quality was assessed by two independent experts, according to a grid adapted from the strengthening the reporting of observational studies in epidemiology (STROBE) statement. RESULTS: Twenty two studies of variable methodological quality were included. Definition of drug exposure varied across studies and depended on the data sources. Potential confounding due to the interaction between the effects of the medicinal drug and disease-related symptoms was often not controlled. The risk of motor-vehicle crashes related to benzodiazepines has been amply studied and demonstrated. Results for other medicinal drugs remain controversial. CONCLUSION: There is a need for large studies, investigating the role of individual substances in the risk of road traffic crashes.

[Adverse drug reactions: a pilot study on patient reporting through patient associations]. / Signalement d'événements indésirables par les patients : étude pilote réalisée avec la collaboration d'associations de patients.

BACKGROUND: The expected evolution of monitoring systems for health products, aims at increasing the involvement of patients into health products safety system. As a result, it seems necessary to consider the ability for patients to directly report their own adverse events. METHODS: A pilot study has been undertaken by Afssaps (Health Agency) for 23 patient associations using a reporting form specially created for patients. RESULTS: According to the analysis of the first 200 reports, received from June 2006 to August 2007, the reported adverse events are mostly serious in terms of consequences on patients' quality of life and expected. The quality of information shows that the proposed tools are adequate and could be used in case of a future change in legislation allowing patient reporting of adverse events. CONCLUSION: The patient, eventually helped by his association, may provide contributory safety information, especially regarding side effects affecting daily life.