Paediatric safety signals identified in VigiBase: Methods and results from Uppsala Monitoring Centre

The evolving role of disproportionality analysis in pharmacovigilance

INTRODUCTION

From 2009 to 2015, the IMI PROTECT conducted rigorous studies addressing questions about optimal implementation and significance of disproportionality analyses, leading to the development of Good Signal Detection Practices. The ensuing period witnessed the independent exploration of research paths proposed by IMI PROTECT, accumulating valuable experience and insights that have yet to be seamlessly integrated.

AREAS COVERED

This state-of-the-art review integrates IMI PROTECT recommendations with recent acquisitions and evolving challenges. It deals with defining the object of study, disproportionality methods, subgrouping, masking, drug-drug interaction, duplication, expectedness, the debated use of disproportionality results as risk measures, integration with other types of data.

EXPERT OPINION

Despite the ongoing skepticism regarding the usefulness of disproportionality analyses and individual case safety reports, their ability to timely detect safety signals regarding rare and unpredictable adverse reactions remains unparalleled. Moreover, recent exploration into their potential for characterizing safety signals revealed valuable insights concerning potential risk factors and the patient's perspective. To fully realize their potential beyond hypothesis generation and achieve a comprehensive evidence synthesis with other kinds of data and studies, each with their unique limitations and contributions, we need to investigate methods for more transparently communicating disproportionality results and mapping and addressing pharmacovigilance biases.

Evaluation of Adverse Drug Events in Patients on Anti-Retroviral Therapy Regimen at Omdurman Voluntary Counselling and Testing and Anti-Retroviral Therapy Center in Sudan - A Cross-Sectional Study

Background

Anti-retroviral therapy-related adverse drug events are accounted as a main cause of anti-retroviral therapy non-adherence. In Sudan, pharmacovigilance studies are relatively rare and obstructed by the problem of under-reporting. It is a well-defined issue worldwide and is highly reported in developing countries. This study aimed to evaluate the prevalence of adverse events associated with anti-retroviral therapy among adult patients with immunodeficiency virus at Omdurman Voluntary Counselling and Testing and Anti-retroviral Therapy Center.

Methods

The study was a descriptive cross-sectional study conducted through direct interviews with 429 patients at the selected center using the Adverse Drug Events (ADEs) reporting form. The collected data were analyzed by The Statistical Package for Social Sciences.

Results

More than half (55.5%) of the participants experienced adverse events, with 48.7% having experienced them at the beginning of treatment. Central nervous system manifestations were the most common adverse events. By using the Naranjo scale, most adverse events showed a "probable" relationship to anti-retroviral medicines. Based on the chi-square test, medication regimen was significantly associated with the presence of ADEs (namely abdominal pain and jaundice) (p values = 0.03 and 0.001), respectively.

Conclusion

This study clearly stated that ART-related ADEs are common among Sudanese PLHIV and with central nervous system being the main adverse events. More pharmacovigilance studies and efforts by healthcare providers should be applied targeting ART-related ADEs under-reporting in Sudanese healthcare facilities.

Off-Label and Unlicenced Medicine Use among Hospitalised Children in South Africa: Practice and Policy Implications

BACKGROUND

Information regarding off-label and unlicensed medicine use among South African children is limited. This is a concern as the prescribing of off-label and unlicensed medicines can lead to issues of effectiveness and safety as well as raise liability issues in the event of adverse events. This potentially exposes physicians to legal penalties. Consequently, we sought to determine the prevalence of off-label and unlicensed medicine use among paediatric patients in South Africa to provide future direction.

METHODS

This study retrospectively examined the use of medicine in a point-prevalence survey study (PPS) involving paediatric patients aged (0-2 years) admitted to selected public hospitals in Gauteng Province, South Africa. Data were collected per hospital over two days between February 2022 and July 2022. Demographics, duration of treatment, diagnosis, and medicines prescribed were collected from patient medical records using a mobile application. Prescribed medicines were reviewed against the medicine formularies and other databases to assess their appropriateness.

RESULTS

From three academic hospitals, 184 patient records were reviewed. A total of 592 medicines were dispensed, of which 379 (64.0%) were licensed and 213 (36.0%) were used off-label/unlicensed for paediatric patients 0-2 years of age. The most prevalent off-label and unlicensed medicines were multivitamins (n = 32, 15.0%) and ampicillin injections (n = 15, 7.0%).

CONCLUSION

The frequency of unlicensed and off-label medicine prescribing shown in this study is consistent with the literature and can be considered high. This practice can pose a risk because it adversely affects patients if not properly regulated. Attention is needed to ensure future high-quality, safe, and effective use of medicines.

Characterization of Pediatric Reports in the US Food and Drug Administration Adverse Event Reporting System from 2010-2020: A Cross-Sectional Study

INTRODUCTION

The Food and Drug Administration Adverse Event Reporting System (FAERS) is a database of adverse event (AE) and medication error reports for drugs and therapeutic biologics. Examining trends of reported individual case safety reports (ICSRs) provides context for evaluating safety concerns.

OBJECTIVE

Characterize pediatric FAERS ICSRs and compare trends (1) to adult reports; (2) within pediatric subgroups.

METHODS

This cross-sectional study examined FAERS ICSRs received between January 1, 2010, through December 31, 2020. Stratified age bands were neonates, infants, younger children, older children, adolescents, and adults. We characterized groups by patient demographic information, suspect products, AEs, and reporter type.

RESULTS

From 2010 to 2020, there were 11,258,995 FAERS ICSRs; 3.1% described pediatric patients. Compared to adults, pediatric ICSRs had higher proportions of all serious outcomes except death. Within pediatric subgroups, neonates had the highest proportions of serious outcomes (96.2%) compared to infants, younger children, older children, and adolescents (79.8%, 67.9%, 59.5%, and 52.7%, respectively). Younger pediatric age groups were more likely to have weight information than older age groups but were less likely to include gender information. The most frequently reported AE was off label use for pediatrics and drug ineffective for adults. Products and AEs reported also differed among pediatric subgroups. Neonates, infants, and adolescents had entirely distinct sets of top five product-event combinations.

CONCLUSION

Pediatric ICSRs represent a minority of FAERS reports but have distinctly different attributes relative to adult ICSRs. Reporting trends also vary within pediatric subgroups, which highlights the need for unique considerations for pediatric safety surveillance.

Identifying Safety Subgroups at Risk: Assessing the Agreement Between Statistical Alerting and Patient Subgroup Risk

INTRODUCTION

Identifying individual characteristics or underlying conditions linked to adverse drug reactions (ADRs) can help optimise the benefit-risk ratio for individuals. A systematic evaluation of statistical methods to identify subgroups potentially at risk using spontaneous ADR report datasets is lacking.

OBJECTIVES

In this study, we aimed to assess concordance between subgroup disproportionality scores and European Medicines Agency Pharmacovigilance Risk Assessment Committee (PRAC) discussions of potential subgroup risk.

METHODS

The subgroup disproportionality method described by Sandberg et al., and variants, were applied to statistically screen for subgroups at potential increased risk of ADRs, using data from the US FDA Adverse Event Reporting System (FAERS) cumulative from 2004 to quarter 2 2021. The reference set used to assess concordance was manually extracted from PRAC minutes from 2015 to 2019. Mentions of subgroups presenting potential differentiated risk and overlapping with the Sandberg method were included.

RESULTS

Twenty-seven PRAC subgroup examples representing 1719 subgroup drug-event combinations (DECs) in FAERS were included. Using the Sandberg methodology, 2 of the 27 could be detected (one for age and one for sex). No subgroup examples for pregnancy and underlying condition were detected. With a methodological variant, 14 of 27 examples could be detected.

CONCLUSIONS

We observed low concordance between subgroup disproportionality scores and PRAC discussions of potential subgroup risk. Subgroup analyses performed better for age and sex, while for covariates not well-captured in FAERS, such as underlying condition and pregnancy, additional data sources should be considered.

Appendicitis as a possible safety signal for the COVID-19 vaccines

This study reviewed cases of appendicitis following administration of COVID-19 vaccines reported to VigiBase, the WHO database of individual case safety reports (ICSRs). Three hundred fifty-eight cases were identified, and disproportionate reporting was noted, with 329 calculated expected cases. Upon review, 24 ICSRs were excluded, so 334 unique ICSRs underwent clinical review from 19 countries. Forty-eight percent of ICSRs reported imaging and 69% noted surgical intervention. The cases were clinically coherent, with an apparent increase in reporting in the four days post-vaccination and a possible dose-response relationship. Appendicitis has been suggested as an adverse event of special interest post-vaccination against COVID-19 after a numerical increase in the vaccine arm of a clinical trial. The case series may be affected by differences in global patterns of reporting, and it is not possible to prove nor disprove causality from this case series. Global longitudinal studies are required to clarify any possible relationship.

Adverse cardiovascular events in patients treated with mogamulizumab

Study objectives

Mogamulizumab is an important treatment for T-cell leukemia and lymphoma. Adverse cardiovascular events (ACE) after mogamulizumab therapy have not been investigated. The aim of the study is to investigate ACE occurrence after mogamulizumab therapy.

Methods

The International World Health Organization database, VigiBase, was analyzed from January 2013 to August 2019 for all adverse events, including ACE, that occurred after mogamulizumab treatment. ACE was defined as: cardiac death, myocardial infarction, heart failure, myocarditis, arrhythmia, vasculitis, thrombosis, palpitations and new hypertension.

Results

ACE after mogamulizumab therapy affected 28 out of 650 unique patients (4.3%). Heart failure (42.8%) and ventricular arrhythmias (17.85%) were most common. ACE accounted for 10% of all fatal adverse outcomes, and 25% of all ACE were fatal. Time to fatal outcome was significantly shorter for patients with ACE compared to non-cardiovascular events, with a mean of 7.7 days (SD 6.91) vs 73 days (SD 90.7), p = 0.017, respectively. There was an increased total number of adverse cardiovascular events in patients greater than 65 and in Asian countries.

Conclusions

Cardiovascular toxicity with mogamulizumab is a possible early occurring adverse outcome associated with high mortality.

Risk Factor Considerations in Statistical Signal Detection: Using Subgroup Disproportionality to Uncover Risk Groups for Adverse Drug Reactions in VigiBase

Introduction

In the treatment of the individual patient, a vision is to achieve the best possible balance between benefit and harm. Such tailored therapy relies upon the identification and characterisation of risk factors for adverse drug reactions. Information relevant to risk factor considerations can be captured in adverse event reports and could be utilised in statistical signal detection.

Objective

The aim of this study was to explore whether statistical screening of a broad range of risk factors within a global database of adverse event reports could uncover signals of risk groups for adverse drug reactions.

Methods

Subgroup disproportionality analysis was applied to 15.4 million reports entered in VigiBase, the World Health Organization (WHO) global database of individual case safety reports, up to August 2017. Disproportionality analyses for drug–adverse event pairs were performed (1) in the full database and (2) across a range of subgroups defined by the following covariates: patient age, sex, body mass index, pregnancy, underlying condition, reporting country, and geographical region. Drug–adverse event pairs disproportionately over-reported in such subgroups, but not in the full database, and with a substantial difference between the two observed-to-expected ratios, were highlighted as statistical signals. These were further prioritised, through filtering and sorting, for clinical assessment, whereafter clinically relevant signals were communicated to the pharmacovigilance community and the public.

Results

Assessments were performed for 354 prioritised statistical signals, resulting in seven communicated signals describing previously unrecognised potential risk groups related to age (elderly), sex (male and female), body mass index (underweight and obese), and geographical region (Asia), all except one for already established adverse drug reactions. Important aspects considered in the assessments included an evaluation of the disproportionate over-reporting in the subgroup by reviewing alternative explanations and reporting patterns for similar drugs/adverse events/subgroups, and a search for plausible mechanisms to support the risk hypothesis.

Conclusions

This study reveals that it is possible to uncover signals of risk groups for adverse drug reactions through incorporation of broad risk factor screening into statistical signal detection in a global database of adverse event reports. Our findings suggest the potential to use such statistical methodologies for risk characterisation in subpopulations of concern.

Electronic supplementary material

The online version of this article (10.1007/s40264-020-00957-w) contains supplementary material, which is available to authorized users.

Evaluating risk detection methods to uncover ontogenic-mediated adverse drug effect mechanisms in children

BACKGROUND

Identifying adverse drugs effects (ADEs) in children, overall and within pediatric age groups, is essential for preventing disability and death from marketed drugs. At the same time, however, detection is challenging due to dynamic biological processes during growth and maturation, called ontogeny, that alter pharmacokinetics and pharmacodynamics. As a result, methodologies in pediatric drug safety have been limited to event surveillance and have not focused on investigating adverse event mechanisms. There is an opportunity to identify drug event patterns within observational databases for evaluating ontogenic-mediated adverse event mechanisms. The first step of which is to establish statistical models that can identify temporal trends of adverse effects across childhood.

RESULTS

Using simulation, we evaluated a population stratification method (the proportional reporting ratio or PRR) and a population modeling method (the generalized additive model or GAM) to identify and quantify ADE risk at varying reporting rates and dynamics. We found that GAMs showed improved performance over the PRR in detecting dynamic drug event reporting across child development stages. Moreover, GAMs exhibited normally distributed and robust ADE risk estimation at all development stages by sharing information across child development stages.

CONCLUSIONS

Our study underscores the opportunity for using population modeling techniques, which leverage drug event reporting across development stages, as biologically-inspired detection methods for evaluating ontogenic mechanisms.

Pediatric adverse reactions to antiseizure medications - An analysis of data from the Italian spontaneous reporting system (2001-2019)

INTRODUCTION

Spontaneous reports of adverse drug reactions (ADRs) are a valuable supplement to clinical studies in informing about the safety of medications. This is especially relevant for pediatric populations, which are not often included in large-scale clinical trials.

OBJECTIVES

To evaluate patterns of pediatric ADRs to antiseizure medications (ASMs) reported to the Italian Spontaneous Reporting System (SRS) database during the period November 1, 2001─May 31, 2019.

METHODS

Suspected ADRs ascribed to medications listed under ATC code N03, plus clobazam (code N05BA09), and affecting individuals below age 18 years were sourced from the Italian SRS database, categorized based on a modification of the MedDRA® high-level term, and analyzed using descriptive statistics.

RESULTS

A total of 956 reports listing a total of 1806 ADRs ascribed to one or more ASMs were received for individuals in pediatric age. The most commonly reported ADRs were skin rashes (24.0% of all reports), epileptic seizures (12.6%), gastrointestinal disturbances (11.8%), and somnolence (10.6%). A more detailed analysis was conducted on 675 reports listing a single ASM as suspected drug and occurring in patients with a specified or presumed diagnosis of epilepsy. Adverse drug reaction patterns differed widely across ASMs. Skin rashes were the most commonly reported ADR for lamotrigine (62.3%), carbamazepine (50.3%), phenobarbital (42.3%), and oxcarbazepine (33.0%). Other most commonly reported ADRs were gastrointestinal symptoms for ethosuximide (44%), irritability/aggression for levetiracetam (25.0%), epileptic seizures for valproic acid (16.1%), fever (often associated with hypohidrosis) for topiramate (17.9%), and utilization error (mostly accidental drug administration) for clonazepam (34.6%).

CONCLUSIONS

Patterns of spontaneous ADR reports are indicative of major differences in safety profile among individual ASMs. Most, but not all, frequently reported ADRs were in line with findings from clinical trials and observational studies.

Automation in signal management in pharmacovigilance-an insight

Drugs are the imperial part of modern society, but along with their therapeutic effects, drugs can also cause adverse effects, which can be mild to morbid. Pharmacovigilance is the process of collection, detection, assessment, monitoring and prevention of adverse drug events in both clinical trials as well as in the post-marketing phase. The recent trends in increasing unknown adverse events, known as signals, have raised the need to develop an ideal system for monitoring and detecting the potential signals timely. The process of signal management comprises of techniques to identify individual case safety reports systematically. Automated signal detection is highly based upon the data mining of the spontaneous reporting system such as reports from health care professional, observational studies, medical literature or from social media. If a signal is not managed properly, it can become an identical risk associated with the drug which can be hazardous for the patient safety and may have fatal outcomes which may impact health care system adversely. Once a signal is detected quantitatively, it can be further processed by the signal management team for the qualitative analysis and further evaluations. The main components of automated signal detection are data extraction, data acquisition, data selection, and data analysis and data evaluation. This system must be developed in the correct format and context, which eventually emphasizes the quality of data collected and leads to the optimal decision-making based upon the scientific evaluation.

Exploratory Study of Signals for Asthma Drugs in Children, Using the EudraVigilance Database of Spontaneous Reports

Introduction

As asthma medications are frequently prescribed for children, knowledge of the safety of these drugs in the paediatric population is important. Although spontaneous reports cannot be used to prove causality of adverse events, they are important in the detection of safety signals.

Objective

Our objective was to provide an overview of adverse drug events associated with asthma medications in children from a spontaneous reports database and to identify new signals.

Methods

Spontaneous reports concerning asthma drugs were obtained from EudraVigilance, the European Medicine Agency’s database for suspected adverse drug reactions. For each drug–event combination, we calculated the proportional reporting ratio (PRR) in the study period 2011–2017. Signals in children (aged 0–17 years) were compared with signals in the whole population. Analyses were repeated for different age categories, by sex and by therapeutic area.

Results

In total, 372,345 reports in children resulted in 385 different signals concerning asthma therapy. The largest group consisted of psychiatric events (65 signals). Only 30 signals were new, with seven, including herpes viral infections, associated with omalizumab. Stratification by age, sex and therapeutic area provided additional new signals, such as hypertrichoses with budesonide and encephalopathies with theophylline. Of all signals in children, 60 (16%) did not appear in the whole population.

Conclusions

The majority of signals regarding asthma therapy in children were already known, but we also identified new signals. We showed that signals can be masked if age stratification is not conducted. Further exploration is needed to investigate the risk and causality of the newly found signals.

Electronic supplementary material

The online version of this article (10.1007/s40264-019-00870-x) contains supplementary material, which is available to authorized users.

Serious Adverse Drug Reactions and Safety Signals in Children: A Nationwide Database Study

Children are more exposed to inappropriate medicine use and its consequent harms. Spontaneous reporting of suspected Serious Adverse Drug Reactions (SADR) increases knowledge and prevention of pharmacotherapy risk. Disproportionality measures are useful to quantify unexpected safety issues associated with a given drug-event pair (signals of disproportionality). This cross-sectional study aimed to assess SADR reporting and safety signals for Brazilian children from 0-12 years old, notified between January 2008 and December 2013 from the Brazilian Surveillance Agency (Notivisa). Information from serious reports (gender and age of the patient, event description, suspected drug) was included. Disproportionality analysis based on Reporting Odds Ratios with a confidence interval of 95% was conducted to identify possible signals of disproportionate reporting (SDR). Almost 30% of 1,977 suspected SADR was related to babies (0-1-year-old). 69% of reports happened with intravenous dosage forms, and 35% of suspected SADR involved off label use according to age. Laronidase, miglustat, imipenem/cilastatin, and clofarabine were involved in six or more suspected deaths among 75 deaths reported. There were 107 SDRs, of which 16 events (15%) were not described in the product labels. There was a relatively higher number of SADRs in Brazilian children compared with studies from other countries. SDRs found, (especially drug-event pairs ‘imipenen/cilastatin–pneumonia’ and ‘laronidase–respiratory insufficiency’) should be investigated more. The reports of SADR with IV dosage forms and OL drug use suggest the need for drug research and the use of better dosage forms for children in Brazil.

Psychiatric adverse drug reactions in the paediatric population

OBJECTIVE

Due to lack of information on drug use in children, many drugs are used off-label in paediatrics. Increased knowledge of adverse drug reactions (ADRs) would enable a better risk-benefit analysis. Our aim was to characterise drugs causing psychiatric ADRs in children by conducting a descriptive study based on pharmacovigilance reports.

DESIGN

Reports submitted to the Netherlands Pharmacovigilance Centre Lareb from 2003 to 2016 were used to investigate drugs causing psychiatric ADRs in the Dutch paediatric population. These data were corrected for drug utilisation in order to correct the number of reports for the number of users of a drug.

MAIN OUTCOME MEASURES

ORs were calculated as a measure of disproportionality for drug-ADR associations for three different age groups. Significant drug-ADR associations were checked if it was labelled in the product information.

RESULTS

Lareb received 918 reports of psychiatric ADRs, which constitute 15% of the reports of ADRs in children. Drugs used for the treatment of ADHD (methylphenidate and atomoxetine) and drugs used for the treatment of asthma (montelukast and fluticasone) were the most frequently reported. However, psychiatric ADRs were also reported for less often prescribed medications such as oxybutynin and isotretinoin.

CONCLUSIONS

Real-world data on psychiatric ADRs in the Dutch paediatric population show a consistent pattern with what is known from drug labels and the literature. Reports of psychiatric ADRs should be taken seriously because of the impact on medication adherence and the well-being of the child and its family.

A 7-Years Active Pharmacovigilance Study of Adverse Drug Reactions Causing Children Admission to a Pediatric Emergency Department in Sicily

Children represent one of the most susceptible groups to adverse drug reactions (ADRs), as a consequence of physiological growth and maturation of different organ systems. The aim of this study was to characterize the frequency, preventability and seriousness of ADRs recorded in the Pediatric Emergency Department (ED) of the University hospital of Messina, in Sicily. All the suspected adverse reactions to drugs and vaccines collected from 2012 to 2018 were selected and then analyzed. Only adverse drug reactions (ADRs) with a probable or possible causality assessment were included, according to the Naranjo Algorithm and the World Health Organization criteria; the preventability assessment using Schumock and Thornton criteria was also carried out. The Medical Dictionary for Regulatory Activities (MedDRA) was used to group ADRs. Of 75,935 admissions to the Pediatric ED, 120 were due to suspected ADRs. The rate of hospital admission due to ADRs (75.8%) was significantly greater than that of patients without ADRs (11.9%). Among pediatric patients with ADRs the median (Q1–Q3) age was 29.5 (12–73.25) months. Most of ADRs were observed in infants and children (43.3% and 41.7%, respectively vs adolescents, 15%). In addition, in children with ADRs, females [41 (14–105)] were older than males [23 (11–45)] (p=0.044). Most adverse reactions were serious (75.8%) and 20.8% were preventable or probably preventable; however, the majority of serious ADRs (93.4%) resulted without sequelae. The reactions were found to be as probable (54.2%) or possible (45.8%). Vaccines (n=63), antibacterials (n=31) and anti-inflammatory medicines (n=14) were the most frequently drugs involved. Organ toxicity mapping due to vaccines was general disorders and administration site conditions (65.1%), nervous disorders (50.2%), cutaneous disorders (35%), followed by gastrointestinal disorders (20.6%). Cutaneous disorders (76%) gastrointestinal (20.7%), general (15.5%), and nervous disorders (8.6%) were the organ toxicity mapping due to drugs. Active pharmacovigilance has an essential role in supporting the development of strategies aimed at intervention to reduce admissions due to ADRs. Our data suggest that ADRs represent the first cause of hospitalization to the Pediatric Emergency Department. Furthermore, according to the literature, vaccines and antibiotics are the most frequent cause of adverse drug reactions in children.

Safety of BRAF+MEK Inhibitor Combinations: Severe Adverse Event Evaluation

Aim: The selective BRAF and MEK inhibitors (BRAFi+MEKi) have substantially improved the survival of melanoma patients with BRAF V600 mutations. However, BRAFi+MEKi can also cause severe or fatal outcomes. We aimed to identify and compare serious adverse events (sAEs) that are significantly associated with BRAFi+MEKi. Methods: In this pharmacovigilance study, we reviewed FDA Adverse Event Reporting System (FAERS) data in order to detect sAE reporting in patients treated with the combination therapies vemurafenib+cobimetinib (V+C), dabrafenib+trametinib (D+T) and encorafenib+binimetinib (E+B). We evaluated the disproportionate reporting of BRAFi+MEKi-associated sAEs. Significant associations were further analyzed to identify combination-specific safety signals among BRAFi+MEKi. Results: From January 2018 through June 2019, we identified 11,721 sAE reports in patients receiving BRAFi+MEKi. Comparison of BRAFi+MEKi combinations demonstrates that skin toxicities, including Stevens–Johnson syndrome, were disproportionally reported using V+C, with an age-adjusted reporting odds ratio (adj. ROR) of 3.4 (95%CI, 2.9–4.0), whereas fever was most significantly associated with D+T treatment with an adj. ROR of 1.9 (95%CI, 1.5–2.4). Significant associations using E+B treatment include peripheral neuropathies (adj. ROR 2.7; 95%CI, 1.2–6.1) and renal disorders (adj. ROR 4.1; 95%CI, 1.3–12.5). Notably, we found an increase in the proportion of Guillain–Barré syndrome reports (adj. ROR 8.5; 95%CI, 2.1–35.0) in patients administered E+B. Conclusion: BRAFi+MEKi combinations share a similar safety profile attributed to class effects, yet concomitantly, these combinations display distinctive effects that can dramatically impact patients’ health. Owing to the limitations of pharmacovigilance studies, some findings warrant further validation. However, the possibility of an increased risk for these events should be considered in patient care.

Adverse drug reactions

An adverse drug reaction (ADR) is defined as a response to a medicinal product which is noxious and unintended. ADRs are an important cause of morbidity and mortality and increase health costs. The pharmacovigilance systems allow the identification and prevention of the risks associated with use of a drug, especially of recently marketed drugs; they detect signals from data of the global ADR register and also support decisions taken by regulatory agencies in different countries. Only a few drugs are withdrawn from the market, mainly due to hepatotoxicity. Spontaneous notification of ADR is the cheapest, simplest and most used method to recognize new safety drug problems, under-reporting being its main limitation. The future of pharmacovigilance and ADRs will include a higher involvement of patients, doctors, health authorities and pharmaceutical companies, and the use of new technologies.

WHODrug: A Global, Validated and Updated Dictionary for Medicinal Information

The WHODrug medicinal information dictionary is a worldwide source of global medicinal information with the aim to facilitate the coding of medications in clinical trials as well as identification of medication-related problems when monitoring patient safety, thereby supporting the development and usage of effective and safe medications. WHODrug contains individual trade names, active ingredients and additional information such as marketing authorisation holder, country of sale, pharmaceutical form and strength. All related medications are linked using a structured WHODrug alphanumeric code, connecting trade names and variation of the ingredient with the active moiety of the ingredient. Medications in WHODrug are classified using the ATC system and clustered into Standardised Drug Groupings, to allow for grouping of medications with one or more properties in common. The built-in data structure and the classification of medications in WHODrug facilitate various ways of aggregating medications for identification and analysis of possible adverse drug reactions. The different information levels in WHODrug are used to explore the relationship between a medication or a class of medications and an adverse event. By using WHODrug in clinical trials and post-marketing safety, accurate and standardised medication information can be achieved globally and allow easy information exchange. To meet the demands of WHODrug users from the pharmaceutical industry, academia and regulatory authorities, it is relevant to keep the dictionary comprehensive, validated and constantly updated on a global scale.

Paediatric safety signals identified in VigiBase: Methods and results from Uppsala Monitoring Centre

Purpose

The purpose of this study is to uncover previously unrecognised risks of medicines in paediatric pharmacovigilance reports and thereby advance a safer use of medicines in paediatrics.

Methods

Individual case safety reports (ICSRs) with ages less than 18 years were retrieved from VigiBase, the World Health Organization (WHO) global database of ICSRs, in September 2014. The reports were grouped according to the following age spans: 0 to 27 days; 28 days to 23 months; 2 to 11 years; and 12 to 17 years. vigiRank, a data‐driven predictive model for emerging safety signals, was used to prioritise the list of drug events by age groups. The list was manually assessed, and potential signals were identified to undergo in‐depth assessment to determine whether a signal should be communicated.

Results

A total of 472 drug‐event pairs by paediatric age groups were the subject of an initial manual assessment. Twenty‐seven drug events from the two older age groups were classified as potential signals. An in‐depth assessment resulted in eight signals, of which one concerned harm in connection with off‐label use of dextromethorphan and another with accidental overdose of olanzapine by young children, and the remaining signals referred to potentially new causal associations for atomoxetine (two signals), temozolamide, deferasirox, levetiracetam, and desloratadine that could be relevant also for adults.

Conclusions

Clinically relevant signals were uncovered in VigiBase by using vigiRank applied to paediatric age groups. Further refinement of the methodology is needed to identify signals in reports with ages under 2 years and to capture signals specific to the paediatric population as a risk group.