Methylphenidate for attention deficit hyperactivity disorder (ADHD) in children and adolescents - assessment of adverse events in non-randomised studies.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in childhood. The psychostimulant methylphenidate is the most frequently used medication to treat it. Several studies have investigated the benefits of methylphenidate, showing possible favourable effects on ADHD symptoms, but the true magnitude of the effect is unknown. Concerning adverse events associated with the treatment, our systematic review of randomised clinical trials (RCTs) demonstrated no increase in serious adverse events, but a high proportion of participants suffered a range of non-serious adverse events. OBJECTIVES: To assess the adverse events associated with methylphenidate treatment for children and adolescents with ADHD in non-randomised studies. SEARCH METHODS: In January 2016, we searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, 12 other databases and two trials registers. We also checked reference lists and contacted authors and pharmaceutical companies to identify additional studies. SELECTION CRITERIA: We included non-randomised study designs. These comprised comparative and non-comparative cohort studies, patient-control studies, patient reports/series and cross-sectional studies of methylphenidate administered at any dosage or formulation. We also included methylphenidate groups from RCTs assessing methylphenidate versus other interventions for ADHD as well as data from follow-up periods in RCTs. Participants had to have an ADHD diagnosis (from the 3rd to the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders or the 9th or 10th edition of theInternational Classification of Diseases, with or without comorbid diagnoses. We required that at least 75% of participants had a normal intellectual capacity (intelligence quotient of more than 70 points) and were aged below 20 years. We excluded studies that used another ADHD drug as a co-intervention. DATA COLLECTION AND ANALYSIS: Fourteen review authors selected studies independently. Two review authors assessed risk of bias independently using the ROBINS-I tool for assessing risk of bias in non-randomised studies of interventions. All review authors extracted data. We defined serious adverse events according to the International Committee of Harmonization as any lethal, life-threatening or life-changing event. We considered all other adverse events to be non-serious adverse events and conducted meta-analyses of data from comparative studies. We calculated meta-analytic estimates of prevalence from non-comparative cohorts studies and synthesised data from patient reports/series qualitatively. We investigated heterogeneity by conducting subgroup analyses, and we also conducted sensitivity analyses. MAIN RESULTS: We included a total of 260 studies: 7 comparative cohort studies, 6 of which compared 968 patients who were exposed to methylphenidate to 166 controls, and 1 which assessed 1224 patients that were exposed or not exposed to methylphenidate during different time periods; 4 patient-control studies (53,192 exposed to methylphenidate and 19,906 controls); 177 non-comparative cohort studies (2,207,751 participants); 2 cross-sectional studies (96 participants) and 70 patient reports/series (206 participants). Participants' ages ranged from 3 years to 20 years. Risk of bias in the included comparative studies ranged from moderate to critical, with most studies showing critical risk of bias. We evaluated all non-comparative studies at critical risk of bias. The GRADE quality rating of the evidence was very low.Primary outcomesIn the comparative studies, methylphenidate increased the risk ratio (RR) of serious adverse events (RR 1.36, 95% confidence interval (CI) 1.17 to 1.57; 2 studies, 72,005 participants); any psychotic disorder (RR 1.36, 95% CI 1.17 to 1.57; 1 study, 71,771 participants); and arrhythmia (RR 1.61, 95% CI 1.48 to 1.74; 1 study, 1224 participants) compared to no intervention.In the non-comparative cohort studies, the proportion of participants on methylphenidate experiencing any serious adverse event was 1.20% (95% CI 0.70% to 2.00%; 50 studies, 162,422 participants). Withdrawal from methylphenidate due to any serious adverse events occurred in 1.20% (95% CI 0.60% to 2.30%; 7 studies, 1173 participants) and adverse events of unknown severity led to withdrawal in 7.30% of participants (95% CI 5.30% to 10.0%; 22 studies, 3708 participants).Secondary outcomesIn the comparative studies, methylphenidate, compared to no intervention, increased the RR of insomnia and sleep problems (RR 2.58, 95% CI 1.24 to 5.34; 3 studies, 425 participants) and decreased appetite (RR 15.06, 95% CI 2.12 to 106.83; 1 study, 335 participants).With non-comparative cohort studies, the proportion of participants on methylphenidate with any non-serious adverse events was 51.2% (95% CI 41.2% to 61.1%; 49 studies, 13,978 participants). These included difficulty falling asleep, 17.9% (95% CI 14.7% to 21.6%; 82 studies, 11,507 participants); headache, 14.4% (95% CI 11.3% to 18.3%; 90 studies, 13,469 participants); abdominal pain, 10.7% (95% CI 8.60% to 13.3%; 79 studies, 11,750 participants); and decreased appetite, 31.1% (95% CI 26.5% to 36.2%; 84 studies, 11,594 participants). Withdrawal of methylphenidate due to non-serious adverse events occurred in 6.20% (95% CI 4.80% to 7.90%; 37 studies, 7142 participants), and 16.2% were withdrawn for unknown reasons (95% CI 13.0% to 19.9%; 57 studies, 8340 participants). AUTHORS' CONCLUSIONS: Our findings suggest that methylphenidate may be associated with a number of serious adverse events as well as a large number of non-serious adverse events in children and adolescents, which often lead to withdrawal of methylphenidate. Our certainty in the evidence is very low, and accordingly, it is not possible to accurately estimate the actual risk of adverse events. It might be higher than reported here.Given the possible association between methylphenidate and the adverse events identified, it may be important to identify people who are most susceptible to adverse events. To do this we must undertake large-scale, high-quality RCTs, along with studies aimed at identifying responders and non-responders.

Cutaneous Porphyrias: Causes, Symptoms, Treatments and the Danish Incidence 1989-2013.

Porphyrias are rare diseases caused by altered haem synthesis leading to the accumulation of different haem intermediates. Neurovisceral attacks may occur in acute porphyrias, while photosensitivity is the presenting symptom in cutaneous porphyrias. We present here an overview of symptoms and a flowchart for the diagnosis of cutaneous porphyrias, with recommendations for monitoring and an update of treatment options. From the Danish Porphyria Register, we present the incidences and approximate prevalences of cutaneous porphyrias within the last 25 years. A total of 650 patients with porphyria cutanea tarda were identified, 73 with erythropoietic protoporphyria, 9 with variegate porphyria, 4 with hereditary coproporphyria and one with congenital erythropoietic porphyria. The total incidence of all porphyrias was ~0.52/100,000 per year.

A multistate model and an algorithm for measuring long-term adherence to medication: a case of diabetes mellitus type 2.

OBJECTIVES: To develop a multistate model and an algorithm for calculating long-term adherence to medication among patients with a chronic disease. METHODS: We propose definitions of the different states of waiting, persistence, with sufficient supply to implement the prescribed dosing regimen, gaps, nonpersistence, and nonacceptance and an algorithm for transitions between states to describe long-term adherence to medication treatment. The model and algorithm are operationalized for use in a case with a retrospective cohort of patients with type 2 diabetes mellitus, with access to records of prescribed drugs from a Danish diabetes research hospital and records of filled prescriptions at Danish pharmacies from the Danish Health and Medicines Authority. RESULTS: Calculations of long-term adherence to medication are shown for patients with type 2 diabetes mellitus on metformin and/or simvastatin. The study shows how the prevalence of patients waiting to initiate treatment, patients with supply to implement the prescribed dosing regimen, patients not accepting treatment, and patients discontinuing treatment varies over time. CONCLUSIONS: The proposed multistate model and algorithm can easily be translated and used for the calculation of adherence to medication in any chronic disease. The model and algorithm take time into account, and thus, changes in incidence rates and prevalence of the different states over time can be estimated on several time scales (calendar time, age of the patient, and time since indication for medication).

Danish physicians' preferences for prescribing escitalopram over citalopram and sertraline to treatment-naïve patients: a national, register-based study.

PURPOSE: To investigate whether general practitioners, hospital physicians and specialized practitioners in psychiatry have similar preferences for initiating treatment with expensive serotonin-specific reuptake inhibitors (SSRIs). METHODS: All first-time prescriptions for the SSRIs escitalopram, citalopram and sertraline reported to the Danish National Register of Medicinal Product Statistics from April 1, 2009 until March 31, 2010 were analysed with regard to treatment naivety and type of prescriber. A prescription was considered as first time if the patient had not received a prescription for the same drug within the last 2 years. Patients who had not received a prescription for an antidepressant within 6 months prior to the date of redemption were classified as treatment-naïve. RESULTS: We included 82,702 first-time prescriptions, 65,313 (79 %) of which were for treatment-naïve patients. Of the treatment-naïve patients, 19 % were initially prescribed escitalopram. Hospital physicians prescribed escitalopram to 34 % of their treatment-naïve patients, while practitioners specialized in psychiatry prescribed it to 25 %, and general practitioners prescribed it to 17 %. General practitioners, however, were responsible for initiating 87 % of all treatment-naïve patients. CONCLUSION: The most expensive SSRI, escitalopram, is prescribed as first choice to one in five patients receiving their first antidepressant of escitalopram, citalopram or sertraline. General practitioners made the bulk of all first-time SSRI prescriptions to treatment-naïve patients.

Using text-mining techniques in electronic patient records to identify ADRs from medicine use.

This literature review included studies that use text-mining techniques in narrative documents stored in electronic patient records (EPRs) to investigate ADRs. We searched PubMed, Embase, Web of Science and International Pharmaceutical Abstracts without restrictions from origin until July 2011. We included empirically based studies on text mining of electronic patient records (EPRs) that focused on detecting ADRs, excluding those that investigated adverse events not related to medicine use. We extracted information on study populations, EPR data sources, frequencies and types of the identified ADRs, medicines associated with ADRs, text-mining algorithms used and their performance. Seven studies, all from the United States, were eligible for inclusion in the review. Studies were published from 2001, the majority between 2009 and 2010. Text-mining techniques varied over time from simple free text searching of outpatient visit notes and inpatient discharge summaries to more advanced techniques involving natural language processing (NLP) of inpatient discharge summaries. Performance appeared to increase with the use of NLP, although many ADRs were still missed. Due to differences in study design and populations, various types of ADRs were identified and thus we could not make comparisons across studies. The review underscores the feasibility and potential of text mining to investigate narrative documents in EPRs for ADRs. However, more empirical studies are needed to evaluate whether text mining of EPRs can be used systematically to collect new information about ADRs.

Prescribing of medicines in the Danish paediatric population outwith the licensed age group: characteristics of adverse drug reactions.

AIM: To identify adverse drug reactions (ADRs) associated with off-label prescribing of medicines in a paediatric population. METHODS: We analysed spontaneous ADR reports for children from ages 0 to 17 years submitted to the Danish national ADR database from 1998 to 2007. We defined off-label prescribing as prescriptions outside the licensed age group. Off-label ADRs were categorized by therapeutic group, age of child, type and severity. The unit of analysis was one ADR. RESULTS: We analysed 4388 ADRs for children reported in the national database. Approximately 17% of reported ADRs were associated with off-label use, 60% of them serious. More than one half of off-label ADRs were reported in adolescents. Serious ADRs due to off-label prescribing are more likely to be reported for hormonal contraceptives (ATC group G), anti-acne preparations (ATC group D) and allergens (ATC group V). CONCLUSION: One-fifth of all ADRs reported over a decade in Danish children was associated with off-label prescribing, and serious ADRs due to off-label prescribing were primarily present in three therapeutic groups: sex hormones, dermatologicals and allergens. There is a need for more research into the prescribing of these medicines in the teenage population, as well as tighter reporting and monitoring of ADRs for medicines prescribed off-label in the paediatric population.

Adverse events following immunization in children: retrospective analysis of spontaneous reports over a decade.

PURPOSE: There is no doubt that paediatric immunization prevents serious diseases, but the administration of these vaccines to healthy children also involves risks of adverse drug reactions (ADRs), some of which are potentially serious. The current body of evidence on ADRs from immunization therapy at the population level is partly contradictory across countries, time periods and childhood immunization programmes. The objective of our study was to characterize reported adverse events (AEFIs) following immunization in Danish children. METHODS: Adverse events (AEFIs) in 0- to 17-year-old children and adolescents reported to the Danish Medicines Agency (DKMA) between 1998 and 2007 were analysed. The unit of analysis was one AEFI. Data were categorized with respect to time, age, and gender of the children, suspected vaccines, category and seriousness of the AEFIs, and reporting rate. RESULTS: During the study period, the DKMA received 1,365 reports covering 2,600 AEFIs, corresponding to 60% of all adverse events reported for children. One third of the AEFIs were classified as serious, and two deaths were reported. The annual number of serious AEFIs remained constant during the study period. Approximately 80% of AEFIs were reported in children aged 0-2 years. Of all reported AEs, 45% were in the category "general disorders and administration site conditions", followed by the categories "skin and subcutaneous tissue disorders" (20% of total AEFIs) and "nervous system disorders" (16% of total AEFIs). The largest share of serious events was from the category "nervous system disorders" (33% of serious AEFIs). The most frequently reported serious AEs were febrile convulsions, pyrexia, and injection-site reactions. CONCLUSIONS: In Denmark, a large number of AEFIs following paediatric immunization have been reported, but the majority of cases were non-serious.

Information about adverse drug reactions reported in children: a qualitative review of empirical studies.

AIM: To review the literature on adverse drug reactions (ADRs) in children with respect to occurrence, seriousness, type, therapeutic group, age and gender of the child and category of reporter. METHODS: Medline and Embase databases were searched from origin and updated until February 2010. We included empirically based articles on ADRs in populations aged 0 to 17 years. Studies monitoring ADRs in patients with particular conditions or drug exposure were excluded. We extracted information about types and seriousness of ADRs, therapeutic groups, age and gender of the child and category of reporter. ADR occurrence was calculated as incidence rate and prevalence. RESULTS: We included 33 studies monitoring ADRs in general paediatric populations. The highest numbers of ADRs were reported in national ADR databases where data were collected over a longer period than in studies monitoring inpatients and outpatients. However, prevalence and incidence were much lower in the national databases. Types of reported ADRs, seriousness of ADRs and types of medicines differed substantially between studies due to differences in time periods and patient populations. Information about ADRs was mainly provided by health care professionals, although parents also contributed reports. CONCLUSIONS: We found a higher incidence rate of ADRs in hospitalized children and outpatients than in national databases. There seems to be considerable potential for increasing the knowledge of ADRs by advocating the submission of reports to the spontaneous reporting systems. Our study underscores that ADRs in children constitute a significant public health problem.

Marketing of healthcare services in Denmark: the concept of misleading advertising.

As severe ill and incurable patients can be easy victims of misleading advertising activities for dangerous and non-effective healthcare treatments, the marketing of healthcare services are in many jurisdictions legislations tightly regulated. This article reviews the Danish regulation on marketing of healthcare services to identify which types of advertising activities that are legal. As the legislation only allows healthcare authorities to control the marketing and not the content and quality of the marketed healthcare services, their ability to intervene in serious cases of misleading advertising is limited. Misleading advertising are statements with the purpose to exaggerate or underestimate the effects and risks of healthcare services or to prevent patients from seeking conventional medical treatments. From a public health perspective, there is a need for a common EU legislation for regulation of the marketing of healthcare services as the increasing use of information technologies makes it possible for the providers to access consumers and patients directly across countries and legal systems.

Opening the white boxes: the licensing documentation of efficacy and safety of psychotropic medicines for children.

PURPOSE: The objective of the present study was to explore the available evidence in a regulatory agency on the safety and efficacy of two types of psychotropic medicine frequently prescribed to children and adolescents. METHODS: We analysed the documentation in registration files, renewal registration files, summaries of product characteristics and scientific assessment reports in the Danish Medicines Agency for two psychotropic medications prescribed for children: methylphenidate and citalopram to discover what data pertaining to the pediatric population are available to the regulatory agency. RESULTS: The licensing of methylphenidate for treating attention-deficit hyperactivity disorders (ADHD) in children from the age of six was based on a single-dose crossover study and, a 2-week double blind, parallel group clinical trial in 100 patients from ages 6 to 12 and published literature. Citalopram is not licensed for pediatric use in Denmark. Citalopram was being investigated in three ongoing clinical trials lasting 8-24 weeks in 423 patients aged 7-18 years. The registration files contained no data on the long-term efficacy and safety of citalopram in pediatric use. Registration material also contained information on planned clinical trials with methylphenidate and citalopram among children/adolescents. CONCLUSIONS: Evidence on the efficacy and safety of methylphenidate and citalopram for pediatric use in the Danish Medicine Agency is limited and supports the need for further clinical trials. Medicine prescription for the pediatric population should be monitored in order to identify risks that were not identified at the time of licensing. The results of clinical trials already conducted should be made publicly available.

Information about ADRs explored by pharmacovigilance approaches: a qualitative review of studies on antibiotics, SSRIs and NSAIDs.

BACKGROUND: Despite surveillance efforts, unexpected and serious adverse drug reactions (ADRs) repeatedly occur after marketing. The aim of this article is to analyse ADRs reported by available ADR signal detection approaches and to explore which information about new and unexpected ADRs these approaches have detected. METHODS: We selected three therapeutic cases for the review: antibiotics for systemic use, non-steroidal anti-inflammatory medicines (NSAID) and selective serotonin re-uptake inhibitors (SSRI). These groups are widely used and represent different therapeutic classes of medicines. The ADR studies were identified through literature search in Medline and Embase. The search was conducted in July 2007. For each therapeutic case, we analysed the time of publication, the strengths of the evidence of safety in the different approaches, reported ADRs and whether the studies have produced new information about ADRs compared to the information available at the time of marketing. RESULTS: 79 studies were eligible for inclusion in the analysis: 23 antibiotics studies, 35 NSAID studies, 20 SSRI studies. Studies were mainly published from the end of the 1990s and onwards. Although the drugs were launched in different decades, both analytical and observational approaches to ADR studies were similar for all three therapeutic cases: antibiotics, NSAIDs and SSRIs. The studies primarily dealt with analyses of ADRs of the type A and B and to a lesser extent C and D, cf. Rawlins' classification system. The therapeutic cases provided similar results with regard to detecting information about new ADRs despite different time periods and organs attacked. Approaches ranging higher in the evidence hierarchy provided information about risks of already known or expected ADRs, while information about new and previously unknown ADRs was only detected by case reports, the lowest ranking approach in the evidence hierarchy. CONCLUSION: Although the medicines were launched in different decades, approaches to the ADR studies were similar for all three therapeutic cases: antibiotics, NSAIDs and SSRIs. Both descriptive and analytical designs were applied. Despite the fact that analytical studies rank higher in the evidence hierarchy, only the lower ranking descriptive case reports/spontaneous reports provided information about new and previously undetected ADRs. This review underscores the importance of systems for spontaneous reporting of ADRs. Therefore, spontaneous reporting should be encouraged further and the information in ADR databases should continuously be subjected to systematic analysis.

Effect of a medicines management model on medication-related readmissions in older patients admitted to a medical acute admission unit-A randomized controlled trial.

RATIONALE, AIMS, AND OBJECTIVES: Medication-related problems are frequent and can lead to serious adverse events resulting in increased morbidity, mortality, and costs. Medication use in frail older patients is even more complex. The aim of this study was to investigate the effect of a pharmacist-led medicines management model among older patients at admission, during inpatient stay and at discharge on medication-related readmissions. METHOD: A randomized controlled trial conducted at the acute admission unit in a Danish hospital with acutely admitted medical patients, randomized to either a control group or one of two intervention groups. The intervention consisted of pharmacist-led medication review and patient interview upon admission (intervention ED) or pharmacist-led medication review and patient interview upon admission, medication review during inpatient stay, and medication report and patient counselling at discharge (intervention STAY). RESULTS: In total, 600 patients were included. The pharmacist identified 920 medication-related problems with 57% of the recommendations accepted by the physician. After 30 days, 25 patients had a medication-related readmission, with no statistical significant difference between the groups on either primary or secondary outcomes. CONCLUSIONS: This study showed that a clinical pharmacist can be used to identify and solve medication-related problems, but this study did not find any effect on the selected outcomes. The frequency of medication-related readmissions was low, leaving little room for improvement. Future research should consider other study designs or outcome measures.

Knowledge creation about ADRs--turning the perspective from the rear mirror to the projector?

UNLABELLED: What is already known about this subject? Serious and unexpected adverse drug reactions (ADRs) have been reported shortly after marketing of a number of drugs. Review of ADR cases by the regulatory authorities has resulted in suspension of drugs or restrictions in product information. What this study adds? Information about serious and unexpected ADRs of three drugs with reported serious ADRs was already present in the registration files. Observations of these ADRs were not investigated further before marketing. A more active utilization of the ADR information in premarketing studies could probably prevent the appearance of unexpected and serious ADR cases after marketing. AIMS: Spontaneous reports of adverse drug reactions (ADRs) are often the only documentation used to justify the recall of drugs from the market. The purpose of this study was to investigate whether it would have been possible to foresee serious ADR cases based on available information on ADRs reported in Phase II and III clinical trials before marketing. METHODS: We conducted a retrospective analysis of reported ADR data in Phase II/III clinical trials in the registration material for three different ADR scenarios: (i) trovafloxacin/alatrofloxacin and hepatotoxicity; (ii) tolcapone and hepatotoxicity and neuroleptic malignant syndrome; and (iii) rituximab and cytokine release syndrome. We chose the scenarios because they were of serious character and caused great damage to the patients and because of different outcomes of the scientific discussions in the regulatory agencies. RESULTS: In all three cases, the registration material contained observations of ADRs, but there had been no follow-up on these observations. ADRs were mentioned in the summary of product information (SPC) purely as information, to some extent accompanied by recommendations. The information was not converted into new knowledge and remained tacit knowledge embedded in the SPCs disseminated to health professionals/prescribers. CONCLUSIONS: The registration material analysed contained information about ADRs that were reported later, meaning that it would have been possible to foresee the occurrence of the ADRs at the time of licensing. More active utilization of the information from Phase II/III clinical trials is recommended to prevent the appearance of unexpected ADRs and further emphasis in SPC warnings to doctors about possible serious ADRs.

Off-label and unlicensed prescribing in Europe: implications for patients' informed consent and liability.

This article reviews the implications of off-label (OL) and unlicensed (UL) medicine use with respect to the legal duty to inform patients and the liability for failure to provide the patient with adequate information on benefits and risks. Informed consent is a legal prerequisite to any medical treatment and requires the physician to inform the patient about benefits and risks important for the patient's decision. Since OL/UL medicine use is common in all fields of medical practice, physicians must be aware of the stricter requirements for information of the patient. The UK High Supreme Court ruled in the case Montgomery v. Lanarkshire Health Board that physicians' information duty is not limited to the level of information that the physician finds important, but to what the patient deems important. In general, violations of the rule of informed consent does not constitute a physical injury, and patients can only claim compensation for damages, if adequate disclosure had been given, and its likely, that patients would have either rejected or opted for an alternative treatment.

Off-Label Prescribing of Antipsychotics in a Danish Child and Adolescent Mental Health Center: A Register-Based Study.

OBJECTIVE: We analyzed prescribing patterns of antipsychotics for children and adolescent affiliated with a Danish Child and Adolescent Mental Health Center) with respect to age, sex, medicine, diagnoses, off-label status, and time. METHODS: We included all patients below 19 years of age prescribed antipsychotics during 2007-2008 and as of November 1, 2014. Prescription data included all antipsychotic prescriptions and prescriptions of concomitant psychotropic medications. We defined an antipsychotic user as a patient receiving at least one prescription during the study period, irrespective of any previous history of antipsychotic use. We defined off-label prescribing as prescriptions outside the licensed age group and approved indication. FINDINGS: We analyzed 404 antipsychotic prescriptions that were located for 150 patients. The patients were between 7 and 18 years of age. Two-thirds of the prescriptions were for girls and two-thirds of prescriptions for olanzapine and quetiapine. Totally, 92% of all prescribed antipsychotics were used off-label. For typical antipsychotics, this share was 96% and for atypical antipsychotics 90%. As of November 1, 2014, the total share of off-label antipsychotic prescriptions was 96%, and 63% of these were for medications prescribed outside the approved age group, and 26% for nonlicensed indication(s). CONCLUSION: This study demonstrated a high level of off-label prescribing over time with respect to age and indication. The prescribing patterns underpin the need for further economic incentives for pharmaceutical companies to register pediatric indications, particular for off-patent products.

Dipeptidyl Peptidase-4 Inhibitor Induced Angioedema - An Overlooked Adverse Drug Reaction?

INTRODUCTION: Angioedema is a potentially fatal adverse drug reaction of some medications, as swellings of the upper airways can cause death by asphyxiation. Angiotensin converting enzymeinhibitors are widely known to cause angioedema but less is known about the association between dipeptidyl peptidase-4 inhibitors (gliptins) and angioedema. Dipeptidyl peptidase-4 inhibitors are antidiabetic drugs used to improve glycaemic control. They, as a class effect, inadvertently affect the degradation of the vasoactive kinins bradykinin and substance P, both of which can cause angioedema due to vasodilatation and increase in vascular permeability in the capillaries. OBJECTIVE: To assess the risk and pathomechanism of angioedema due to inhibition of dipeptidyl peptidase- 4 inhibitors when used as monotherapy and in combination with angiotensin converting enzymeinhibitors. METHOD: PubMed, Embase, the Cochrane Library, PubMed Central, Web of Science, Google Scholar and clinicaltrials.gov were searched using different combinations of keywords "angioedema", "dipeptidyl peptidase 4", "dipeptidyl peptidase 4 inhibitors", "gliptins", "bradykinin", "substance P" and "angiotensin converting enzyme-inhibitors". Original research papers were preferably used as references and their bibliographies were used to further the search for original research results. RESULTS: Both angiotensin converting enzyme and dipeptidyl peptidase-4 are major enzymes in the degradation pathway of bradykinin and substance P, and when inhibited pharmacologically - especially at the same time - the theoretical risk of angioedema is increased due to accumulation of vasoactive kinins. CONCLUSION: Treatment with dipeptidyl peptidase-4 inhibitors must be carefully considered and monitored especially during concurrent treatment with angiotensin converting enzyme-inhibitors or when treating patients with a known predisposition to angioedema.

Creating knowledge about adverse drug reactions: a critical analysis of the Danish reporting system from 1968 to 2005.

Data on adverse drug reactions (ADRs) have been collected in Denmark since 1968 and the process is ongoing. This article explores knowledge created by the system, including how the collected data have been used to monitor the safety of licensed drugs. Nonaka's theory of knowledge creation was used to discriminate between tacit and explicit knowledge. A total of 56,802 ADR case reports were received from 1968 to 2005. The analysis shows a rather stable number of ADR cases from 1980, with about 2000 reports per year. The distribution of cases into serious and non-serious ADRs has been one to four throughout the period under study, but with large variations. Analysis of selected ADR cases shows that the system lacked the potential to capture available knowledge. Consequently the ADR reports have had limited value and significance in the process of creating scientific knowledge. Thus, the analysis questions the way available data can become explicit as a basis for regulatory decisions and whether all data can become knowledge, including who decides what knowledge is.

Specific Genes Associated with Adverse Events of Methylphenidate Use in the Pediatric Population: A Systematic Literature Review.

The aim of this study was to review empirical studies examining associations between candidate genes and adverse events (AEs) from methylphenidate (MPH) use in children and adolescents. The PubMed, EMBASE, CINAHL, and Web of Science databases were searched from their inception until March 2017. We included empirically based articles on pharmacogenetic studies in 0-17-year-old patients that investigated associations between specific candidate genes, their polymorphisms, and reported AEs. We extracted information about study design, setting, type of AE reporter, studied genes and their polymorphisms, age and gender, administered doses, method of genotyping, outcome measures, and main findings. A total of nine articles reporting information about four double-blind, placebo-controlled, cross-over studies and five open-label cohort studies were eligible for inclusion. Studies were published from 2006 onward and included a total of 998 patients (3-17-year-olds) diagnosed with attention-deficit hyperactivity disorder (ADHD). Studies predominantly involved males and lasted from 1 to 12 weeks. Studies used polymerase chain reaction and single nucleotide polymorphism genotyping methodology. Reported AEs were significantly associated with the following genes: appetite reduction (CES1*G); buccal-lingual movements (T1065G); diastolic blood pressure (ADRA2A Mspl C/C-GC); emotionality (DAT1*9/9); irritability (SNAP25 T1065G); picking (DRD4*7/DRD4*4); social withdrawal (DRD4*7/DRD4*4); somatic complaints (DAT1*10/10); tics (5-HTTLRP*S/L*L/L; SNAP25 T1065G); sadness (CES1*rsl12443580); and vegetative symptoms (5-HTTLPR). In conclusion, only few MPH pediatric pharmacogenetic studies were located, and large between-study heterogeneity was found. Studies were of naturalistic design and of short duration. They included small patient samples, poorly standardized treatment regimens, and limited outcome assessments. In the future, more pharmacogenomic studies in ADHD are needed, preferably using randomized, controlled study designs and of longer duration (more than 6 months).

Long-term patterns of adherence to medication therapy among patients with type 2 diabetes mellitus in Denmark: The importance of initiation.

AIMS: Poor adherence to medication therapy among type 2 diabetes patients is a clinical challenge. We aimed to determine which factors are associated with the three phases of long-term adherence to medication: initiation, implementation and discontinuation in a register-based study. METHODS: Adherence to six medicine groups (metformin, sulfonylureas, acetylsalicylic acid, thiazide diuretics, renin angiotensin system inhibitors, and statins) were analysed among 5,232 patients with type 2 diabetes at a tertiary referral hospital during 1998-2009. Rate-ratios of initiation of treatment, recurrent gaps in supply of medication, and discontinuation of treatment were analysed using Poisson regression. RESULTS: Poor initiation rather than poor implementation or discontinuation was the main contributor to medication nonadherence. Polypharmacy was a risk factor for slower initiation of treatment for all six medicine groups (rate ratio ranging 0.79 95%CI [0.72-0.87] to 0.89 95%CI [0.82-0.96] per already prescribed medicine), but once patients were in treatment, polypharmacy was not associated with recurrence of gaps in supply of medication, and polypharmacy was associated with lower risk of discontinuation (rate ratio ranging 0.93 95%CI [0.86-1.00] to 0.96 95%CI [0.93-0.99] per prescribed medicine). Other identified risk factors for slow initiation, poor implementation, and discontinuation were diabetes duration, younger age, and Turkish/Pakistani origin. DISCUSSION: This study showed that a risk factor does not necessarily have the same association with all three elements of adherence (initiation, implementation and discontinuation), and that efforts supporting patients introduced to more complex drug combinations should be prioritized.