Active monitoring of adverse drug reactions in children. Italian Paediatric Pharmacosurveillance Multicenter Group

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.

Drug Allergy in Children: What Should We Know?

The drug allergy "label" may have a lifetime of consequences for a child. Many children with alleged drug allergies are proven to be tolerant to the culprit medication when challenged. The field of drug hypersensitivity is a recently evolving field of research, but studies on its epidemiology and diagnostic tools are lacking in children. Clinical history is significant in the diagnosis and classification of drug hypersensitivity in children. Diagnostic tools have been evaluated in a limited number of children; therefore, the guidelines are mainly in line with those for adults. Here, we review the clinical characteristics, main drugs, risk factors, and diagnosis of drug hypersensitivity to aid in its accurate diagnosis in children.

Reported Adverse Drug Reactions in Infants: A Nationwide Analysis in Malaysia

Spontaneous adverse drug reactions (ADRs) reporting is a useful source of drug safety information in infants as only adult patients are routinely tested in clinical trials. This study was aimed to evaluate the spontaneously reported ADRs using WHO Adverse Reaction Terminology and to identify the common drugs associated with ADRs in children under 2 years of age. A retrospective analysis of ADR data for children below 2 years old from 2000 to 2013 was conducted using the data extracted from Malaysia’s national pharmacovigilance database, QUEST2 System. From 2000 to 2013, Malaysia’s National Pharmaceutical Control Bureau received a total of 11,932 reports for children from various healthcare facilities in Malaysia. 14.0% (n = 1667) of the ADRs reported for those children were related to children under 2 years old. The data retrieved was analyzed in terms of age, gender, source of reporting, type of reporters, suspected medicines and characteristics of ADRs (category, onset, severity, and outcomes). A total of 1312 ADRs reported in 907 ADR reports were analyzed. The most common ADRs reported were skin appendage disorders (60.1%), and the most frequently reported symptoms were rash (n = 215), maculopapular rash (n = 206), urticaria (n = 169), erythematous rash (n = 76), and pruritus (n = 58). In general, drugs from antibacterials for systemic use (58.8%) appeared to be the most common contributors to ADRs in children below 2 years old. Penicillins and other β-Lactam Antibacterials accounted for more than 40% of all drugs implicated in ADRs. The majority of ADRs were subacute reactions that occurred within 24 h of exposure to the drug. A high proportion of ADRs was classified as mild, and most victims had no sequela. Only one fatality was seen. There were 10 cases for each symptom, namely erythema multiforme and Stevens–Johnson Syndrome, observed in this study. A large proportion of ADRs in children under 2 years old were mainly caused by drugs from antibacterial for systemic use, with most of the ADRs manifesting in skin reactions. This study also reveals rare cutaneous ADRs experienced by Malaysian children under the age of 2, which constitutes a crucial cause of harm among children.

Adverse Drug Reactions in Pediatric Emergency Medicine

BACKGROUND

The pediatric population displays its own pharmacological characteristics, making children vulnerable to adverse drug reactions (ADRs).

OBJECTIVE

To determine the incidence of ADRs among the pediatric emergency department (PED) population.

METHODS

This is a descriptive, noncontrolled, prospective, and single-center study, during 4 consecutive months in the PED of Nantes University Hospital.

RESULTS

Setting up active gathering of data on ADRs enabled 121 reports of 11 095 consultations at the emergency department, which corresponds to an ADR incidence of 1.09%. Digestive and cutaneous reactions made up the majority of reactions judged as being nonserious (53%) and were mainly found in children between 2 -11 years old. Of the serious ADRs, 25% were found in the 12-15-year-old age range because of the drug overdose. The main medications administered, which were responsible for the majority of the ADRs, were an equimolar mix of oxygen and nitrogen monoxide, amoxicillin, and acetaminophen. Three means of collecting data were possible: collecting files data, oral communication, or filling a form, the last being the most used method.

CONCLUSIONS

This active data gathering shows the incidence and nature of the adverse effects as well as the age distribution in the PED population. It highlights the considerable misuse of medications among young teenagers and the high incidence of overmedication in the younger age group. This work also revealed the need for a better reporting system. Future joint studies should be carried out between clinical and pharmacological departments to optimize communication and the correct use of medications in children.

Cutaneous drug reactions in children: a multicentric study

Introduction

According to studies conducted in outpatients, it is estimated that 2.5% of children who are treated with a drug will experience a cutaneous adverse drug reaction (CADR).

Aim

To analyze the CADR reports involving pediatric patients recorded by three different university hospitals for describing common, serious, and interesting cutaneous drug eruption patterns.

Material and methods

For this purpose, the patients’ data from three different universities were reviewed retrospectively. Diagnosis was based on history, clinical findings and laboratory test results. The CADRs were classified into seven categories; urticaria, angioedema, maculopapular eruption, fixed drug eruption, erythema multiforme, acute generalized exanthematous pustulosis, drug rash with eosinophilia and systemic symptoms syndrome.

Results

A total of 122 patients who had CADRs were enrolled in the study. The most frequently detected cutaneous drug reactions were urticaria + angioedema. Most of patients had no previous experience with the same drug and the most common causative agent of CADRs was antimicrobials.

Conclusions

Since CADRs are relatively rare, the current multicentric study can provide meaningful information about the cutaneous eruption patterns of commonly used drugs.

Pharmacovigilance for children's sake

Child age-specific information on efficacy and risk of medicines can be limited for healthcare professionals and patients. It is therefore very important to make the best use of a risk planned approach to the pharmacological treatment of children. This means pharmacovigilance in the broadest sense of gaining the best data from the use of medicines in clinical practice. We consider issues that complicate safe medication use in paediatric care, as well as current progress and provide suggestions for building knowledge within paediatric pharmacovigilance to be used to minimise patient harm. The continuous development in children constitutes a challenge to prescribing and administering age-suitable doses for individual children. Children are not only different from adults but differ vastly within their own age group. Physical growth during childhood is apparent to the eye, but less obvious is the ongoing maturation of organ function important for drug disposition and action. Systematic issues such as medication errors, off-label use and the lack of age-suitable formulations are considerable obstacles for safe medication use in paediatrics. The recognition of emerging adverse drug reactions could be more challenging in developing children. Initiatives to improve the situation have been made by the WHO and regulators in the USA and EU. Age-specific changes in physiology, pharmacology and psychology, as well as systematic issues specific for children need to be considered in the work of assessing spontaneous reports in children. Pharmacovigilance needs to broaden its aims considerably beyond merely capturing new associations between drugs and events, and encompass careful collection on patient characteristics and circumstances around the reported adverse drug reaction to provide essential information that will give clues on how to prevent harm to children.

ADRIC: Adverse Drug Reactions In Children – a programme of research using mixed methods

Aims

To comprehensively investigate the incidence, nature and risk factors of adverse drug reactions (ADRs) in a hospital-based population of children, with rigorous assessment of causality, severity and avoidability, and to assess the consequent impact on children and families. We aimed to improve the assessment of ADRs by development of new tools to assess causality and avoidability, and to minimise the impact on families by developing better strategies for communication.

Review methods

Two prospective observational studies, each over 1 year, were conducted to assess ADRs in children associated with admission to hospital, and those occurring in children who were in hospital for longer than 48 hours. We conducted a comprehensive systematic review of ADRs in children. We used the findings from these studies to develop and validate tools to assess causality and avoidability of ADRs, and conducted interviews with parents and children who had experienced ADRs, using these findings to develop a leaflet for parents to inform a communication strategy about ADRs.

Results

The estimated incidence of ADRs detected in children on admission to hospital was 2.9% [95% confidence interval (CI) 2.5% to 3.3%]. Of the reactions, 22.1% (95% CI 17% to 28%) were either definitely or possibly avoidable. Prescriptions originating in the community accounted for 44 out of 249 (17.7%) of ADRs, the remainder originating from hospital. A total of 120 out of 249 (48.2%) reactions resulted from treatment for malignancies. Off-label and/or unlicensed (OLUL) medicines were more likely to be implicated in an ADR than authorised medicines [relative risk (RR) 1.67, 95% CI 1.38 to 2.02;p < 0.001]. When medicines used for the treatment of oncology patients were excluded, OLUL medicines were not more likely to be implicated in an ADR than authorised medicines (RR 1.03, 95% CI 0.72 to 1.48;p = 0.830). For children who had been in hospital for > 48 hours, the overall incidence of definite and probable ADRs based on all admissions was 15.9% (95% CI 15.0 to 16.8). Opiate analgesic drugs and drugs used in general anaesthesia (GA) accounted for > 50% of all drugs implicated in ADRs. The odds ratio of an OLUL drug being implicated in an ADR compared with an authorised drug was 2.25 (95% CI 1.95 to 2.59;p < 0.001). Risk factors identified were exposure to a GA, age, oncology treatment and number of medicines. The systematic review estimated that the incidence rates for ADRs causing hospital admission ranged from 0.4% to 10.3% of all children [pooled estimate of 2.9% (95% CI 2.6% to 3.1%)] and from 0.6% to 16.8% of all children exposed to a drug during hospital stay. New tools to assess causality and avoidability of ADRs have been developed and validated. Many parents described being dissatisfied with clinician communication about ADRs, whereas parents of children with cancer emphasised confidence in clinician management of ADRs and the way clinicians communicated about medicines. The accounts of children and young people largely reflected parents’ accounts. Clinicians described using all of the features of communication that parents wanted to see, but made active decisions about when and what to communicate to families about suspected ADRs, which meant that communication may not always match families’ needs and expectations. We developed a leaflet to assist clinicians in communicating ADRs to parents.

Conclusion

The Adverse Drug Reactions In Children (ADRIC) programme has provided the most comprehensive assessment, to date, of the size and nature of ADRs in children presenting to, and cared for in, hospital, and the outputs that have resulted will improve the management and understanding of ADRs in children and adults within the NHS. Recommendations for future research: assess the values that parents and children place on the use of different medicines and the risks that they will find acceptable within these contexts; focusing on high-risk drugs identified in ADRIC, determine the optimum drug dose for children through the development of a gold standard practice for the extrapolation of adult drug doses, alongside targeted pharmacokinetic/pharmacodynamic studies; assess the research and clinical applications of the Liverpool Causality Assessment Tool and the Liverpool Avoidability Assessment Tool; evaluate, in more detail, morbidities associated with anaesthesia and surgery in children, including follow-up in the community and in the home setting and an assessment of the most appropriate treatment regimens to prevent pain, vomiting and other postoperative complications; further evaluate strategies for communication with families, children and young people about ADRs; and quantify ADRs in other settings, for example critical care and neonatology.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Knowledge discovery of drug data on the example of adverse reaction prediction

BACKGROUND

Antibiotics are the widely prescribed drugs for children and most likely to be related with adverse reactions. Record on adverse reactions and allergies from antibiotics considerably affect the prescription choices. We consider this a biomedical decision-making problem and explore hidden knowledge in survey results on data extracted from a big data pool of health records of children, from the Health Center of Osijek, Eastern Croatia.

RESULTS

We applied and evaluated a k-means algorithm to the dataset to generate some clusters which have similar features. Our results highlight that some type of antibiotics form different clusters, which insight is most helpful for the clinician to support better decision-making.

CONCLUSIONS

Medical professionals can investigate the clusters which our study revealed, thus gaining useful knowledge and insight into this data for their clinical studies.

Antibiotic allergies in children and adults: from clinical symptoms to skin testing diagnosis

Hypersensitivity reactions to β-lactam and non-β-lactam antibiotics are commonly reported. They can be classified as immediate or nonimmediate according to the time interval between the last drug administration and their onset. Immediate reactions occur within 1 hour after the last drug administration and are manifested clinically by urticaria and/or angioedema, rhinitis, bronchospasm, and anaphylactic shock; they may be mediated by specific IgE-antibodies. Nonimmediate reactions occur more than 1 hour after the last drug administration. The most common manifestations are maculopapular exanthems; specific T lymphocytes may be involved in this type of manifestation. The diagnostic evaluation of hypersensitivity reactions to antibiotics is usually complex. The patient's history is fundamental; the allergic examination is based mainly on in vivo tests selected on the basis of the clinical features and the type of reaction, immediate or nonimmediate. Immediate reactions can be assessed by immediate-reading skin tests and, in selected cases, drug provocation tests. Nonimmediate reactions can be assessed by delayed-reading skin tests, patch tests, and drug provocation tests. However, skin tests have been well validated mainly for β-lactams but less for other classes of antibiotics.

Cutaneous drug reactions in the pediatric population

Cutaneous adverse drug reactions (ADRs) constitute a major pediatric health problem frequently encountered in clinical practice, and represent a diagnostic challenge. Children are more susceptible than adults to errors in drug dosage because of their smaller body size; moreover, ADRs can mimic other skin diseases of children, especially viral exanthems. Most ADRs with cutaneous involvement are mild and resolve on withdrawal of the causative drug. The most common forms of cutaneous ADRs, maculopapular exanthems and urticarial reactions, have excellent outcomes. Less frequent but more severe reactions may incur a risk of mortality.

Pharmacy study of natural health product adverse reactions (SONAR): a cross-sectional study using active surveillance in community pharmacies to detect adverse events associated with natural health products and assess causality

OBJECTIVES

To investigate the rates and causality of adverse event(s) (AE) associated with natural health product (NHP) use, prescription drug use and concurrent NHP-drug use through active surveillance in community pharmacies.

DESIGN

Cross-sectional study of screened patients.

SETTING

10 community pharmacies across Alberta and British Columbia, Canada from 14 January to 30 July 2011.

PARTICIPANTS

The participating pharmacy staff screened consecutive patients, or agents of patients, who were dropping or picking up prescription medications.

PRIMARY OUTCOME MEASURES

Patients were screened to determine the proportions of them using prescription drugs and/or NHPs, as well as their respective AE rates. All AEs reported by the screened patients who took a NHP, consented to, and were available for, a detailed telephone interview (14%) were adjudicated fully to assess for causality.

RESULTS

Over a total of 105 pharmacy weeks and 1118 patients screened, 410 patients reported taking prescription drugs only (36.7%; 95% CI 33.9% to 39.5%), 37 reported taking NHPs only (3.3%; 95% CI 2.4% to 4.5%) and 657 reported taking prescription drugs and NHPs concurrently (58.8%; 95% CI 55.9% to 61.6%). In total, 54 patients reported an AE, representing 1.2% (95% CI 0.51% to 2.9%), 2.7% (95% CI 0.4% to 16.9%) and 7.3% (95% CI 5.6% to 9.6%) of each population, respectively. Compared with patients who reported using prescription drugs, the patients who reported using prescription drugs and NHPs concurrently were 6.4 times more likely to experience an AE (OR; 95% CI 2.52 to 16.17; p<0.001). Combined with data from Ontario, Canada, a national proportion was calculated, which found that 45.4% (95% CI 43.8% to 47.0%) of Canadians who visit community pharmacies take NHPs and prescription drugs concurrently, and of those, 7.4% (95% CI 6.3% to 8.8%) report an AE.

CONCLUSIONS

A substantial proportion of community pharmacy patients use prescription drugs and NHPs concurrently; these patients are at a greater risk of experiencing an AE. Active surveillance provides a means of detecting such AEs and collecting high-quality data on which causality assessment can be based.

Beta-lactam hypersensitivity in children with cystic fibrosis: a study in a specialized pediatric center for cystic fibrosis and drug allergy

BACKGROUND

Beta-lactam hypersensitivity (HS) is suspected in 5-12% of the children, but proven in only 10-15% of those children, based on skin and challenge tests results. In contrast, 30-60% of patients with cystic fibrosis (CF) are diagnosed allergic to beta-lactams, based mainly on the clinical history of the patients.

OBJECTIVES

To confirm or rule out a suspected beta-lactam HS in CF children and to determine the prevalences of suspected and confirmed beta-lactam HS in those children.

PATIENTS AND METHODS

Children with CF and suspected beta-lactam HS were explored by means of skin and challenge tests with the suspected and alternate beta-lactams. The results in CF children were compared with those reported in the literature in non- CF children.

RESULTS

Eight of the 701 CF children followed in our center between 1990 and 2011 (1.14%), and 11 other children from other centers were explored for suspected beta-lactam HS. Beta-lactam HS was diagnosed in nine of these children (47.3%). Based on the results in the children followed in our center, the prevalence of beta-lactam HS was 0.71% (5/701) in CF children vs. a mean estimated prevalence of 1-1.5% in the general pediatric population.

CONCLUSION

Our results contrast with those of most previous studies. Although half of the CF children with suspected beta-lactam HS were truly allergic to beta-lactams, the general prevalence of beta-lactam HS in CF children was very low. This may result from tolerance induced by frequent and/or prolonged treatments with beta-lactams.

Cutaneous drug reactions in children: an update

Cutaneous drug reactions account for a large proportion of adverse drug reactions. Cutaneous drug reactions can be very challenging to diagnose. They can mimic many other skin diseases; this is especially evident during childhood, when viral exanthems are commonplace. Also, if a patient is taking numerous medications, establishing causality to a specific drug can be multifaceted and difficult. The purpose of this review is to highlight an approach to the diagnosis of a suspected cutaneous drug reaction in a child. We have classified different types of drug eruptions by morphology: exanthematous, urticarial, pustular, and bullous. Within each of these groups we have divided them into simple, benign, or non-febrile and complex or febrile reactions. We also include a miscellaneous group to ensure a methodical review.

Stevens-johnson syndrome associated with drugs and vaccines in children: a case-control study

OBJECTIVE

Stevens-Johnson Syndrome (SJS) is one of the most severe muco-cutaneous diseases and its occurrence is often attributed to drug use. The aim of the present study is to quantify the risk of SJS in association with drug and vaccine use in children.

METHODS

A multicenter surveillance of children hospitalized through the emergency departments for acute conditions of interest is currently ongoing in Italy. Cases with a diagnosis of SJS were retrieved from all admissions. Parents were interviewed on child's use of drugs and vaccines preceding the onset of symptoms that led to the hospitalization. We compared the use of drugs and vaccines in cases with the corresponding use in a control group of children hospitalized for acute neurological conditions.

RESULTS

Twenty-nine children with a diagnosis of SJS and 1,362 with neurological disorders were hospitalized between 1(st) November 1999 and 31(st) October 2012. Cases were more frequently exposed to drugs (79% vs 58% in the control group; adjusted OR 2.4; 95% CI 1.0-6.1). Anticonvulsants presented the highest adjusted OR: 26.8 (95% CI 8.4-86.0). Significantly elevated risks were also estimated for antibiotics use (adjusted OR 3.3; 95% CI 1.5-7.2), corticosteroids (adjusted OR 4.2; 95% CI 1.8-9.9) and paracetamol (adjusted OR 3.2; 95% CI 1.5-6.9). No increased risk was estimated for vaccines (adjusted OR: 0.9; 95% CI 0.3-2.8).

DISCUSSION

Our study provides additional evidence on the etiologic role of drugs and vaccines in the occurrence of SJS in children.

Desensitization to antibiotics in children

Drug hypersensitivity reactions can occur to almost all drugs and antibiotics are among the most common cause for this kind of reactions. Drug hypersensitivity may affect any organ or system, and manifestations range widely in clinical severity from mild pruritus to anaphylaxis. In most cases, the suspected drug is avoided in the future. In case of infection, there is usually a safe antibiotic alternative. Nonetheless, in some cases, no alternative treatment exists for optimal therapy. Under these circumstances, desensitization may be performed. Drug desensitization is defined as the induction of a temporary state of tolerance to a drug which can only be maintained by continuous administration of the medication responsible for the hypersensitivity reaction. Desensitization is mainly performed in IgE-mediated reactions. Increasing doses of the implicated drug are administered over a short period of time, until the therapeutic dose is achieved and tolerated. Very few studies confined to children are found in literature. Most of them are case reports. In general, the proposed desensitization schemes are similar to those used in adults differing only in the final dose administered. The purpose of this study is to review desensitization to antibiotics in children presenting and discussing three clinical practical cases of desensitization in this age group.

Pharmacovigilance of malaria intermittent preventive treatment in infants coupled with routine immunizations in 6 African countries

BACKGROUND

Intermittent preventive treatment in infants (IPTi) is a new malaria control strategy coupled with the delivery of routine immunizations recommended by the World Health Organization since 2009 for countries with moderate to high endemicity. To evaluate its safety profile and identify potential new adverse events (AEs) following simultaneous administration of sulfadoxine-pyrimethamine (SP-IPTi) with immunizations, we measured AE incidence and evaluated spontaneous AE reporting.

METHODS

A cohort event monitoring study was conducted on 24 000 infants in 2 countries after administration of SP-IPTi during routine immunizations. Additional pharmacovigilance training and supervision were conducted to stimulate AE passive reporting in 6 African countries.

RESULTS

No serious AEs were found by active follow-up, representing 95% probability that the rate does not exceed 1 per 8000. No serious AEs were found by retrospective review of hospital registers. The rate of moderate AEs probably linked to immunization and/or SP-IPTi was 1.8 per 1000 doses (95% confidence interval, 1.50-2.00). Spontaneous reporting of AEs remained <1% of cases collected by active follow-up.

CONCLUSIONS

Simultaneous administration of SP-IPTi and immunizations is a safe strategy for implementation with a low risk of serious AEs to infants. Strategies toward strengthening spontaneous reporting in Africa should include not only the provider but also beneficiaries or their caregivers.

Adverse drug reactions in children--a systematic review

BACKGROUND

Adverse drug reactions in children are an important public health problem. We have undertaken a systematic review of observational studies in children in three settings: causing admission to hospital, occurring during hospital stay and occurring in the community. We were particularly interested in understanding how ADRs might be better detected, assessed and avoided.

METHODS AND FINDINGS

We searched nineteen electronic databases using a comprehensive search strategy. In total, 102 studies were included. The primary outcome was any clinical event described as an adverse drug reaction to one or more drugs. Additional information relating to the ADR was collected: associated drug classification; clinical presentation; associated risk factors; methods used for assessing causality, severity, and avoidability. Seventy one percent (72/102) of studies assessed causality, and thirty four percent (34/102) performed a severity assessment. Only nineteen studies (19%) assessed avoidability. Incidence rates for ADRs causing hospital admission ranged from 0.4% to 10.3% of all children (pooled estimate of 2.9% (2.6%, 3.1%)) and from 0.6% to 16.8% of all children exposed to a drug during hospital stay. Anti-infectives and anti-epileptics were the most frequently reported therapeutic class associated with ADRs in children admitted to hospital (17 studies; 12 studies respectively) and children in hospital (24 studies; 14 studies respectively), while anti-infectives and non-steroidal anti-inflammatory drugs (NSAIDs) were frequently reported as associated with ADRs in outpatient children (13 studies; 6 studies respectively). Fourteen studies reported rates ranging from 7%-98% of ADRs being either definitely/possibly avoidable.

CONCLUSIONS

There is extensive literature which investigates ADRs in children. Although these studies provide estimates of incidence in different settings and some indication of the therapeutic classes most frequently associated with ADRs, further work is needed to address how such ADRs may be prevented.

Effects of safety warnings on prescription rates of cough and cold medicines in children below 2 years of age

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Cough and cold medicines are frequently used in children to treat upper respiratory tract infections without solid proof of benefits. • Safety issues have been raised about the use of these drugs in young children. • In 2007 international warnings were issued advising against use of these drugs in young children.

WHAT THIS STUDY ADDS

• Cough and cold medicines prescribing by primary care physicians has not really been influenced by international warnings in the Netherlands, where no additional national warnings were made and only partially in Italy. • A concerted action should be taken in Europe to advise strongly against the OTC use and prescription of cough and cold medicines in young children.

AIM

The aim of the study was to assess the influence of national and international warnings on the prescription rates of cough and cold medicines (CCMs) in the youngest children (<2 years) in the Netherlands and Italy.

METHODS

Analysis of outpatient electronic medical records of children <2 years in Italy and the Netherlands was carried out. Age and country specific prescription prevalence rates were calculated for the period 2005-08. Comparisons of prescription rates in 2005 (pre) and 2008 (post) warnings were done by means of a chi-square test.

RESULTS

The cohort consisted of 99,176 children <2 years of age. After international warnings, overall prescription rates for CCMs decreased slightly from 83 to 77/1000 person years (P= 0.05) in Italy and increased in the Netherlands from 74 to 92/1000 children per year. Despite the international warnings, prescription rates for nasal sympathomimetics and opium alkaloids increased in the Netherlands (P < 0.01). In Italy a significant decrease in the prescription rates of opium alkaloids and other cough suppressants (P < 0.01) was observed, and also a significant reduction in use of combinations of nasal sympathomimetics.

CONCLUSION

Despite the international safety warnings and negative benefit-risk profiles, prescription rates of cough and cold medicines remain substantial and were hardly affected by the warnings, especially in the Netherlands where no warning was issued. The hazards of use of these medicines in young children should be explicitly stipulated by the European Medicines Agency and all national agencies, in order to increase awareness amongst physicians and caretakers and reduce heterogeneity across the EU.

Diagnosis of drug hypersensitivity in children and adolescents: discrepancy between physician-based assessment and results of testing

BACKGROUND

Diagnosis of drug hypersensitivity is often based on history alone. But such a vague diagnosis may cause limitations of therapeutic options in the future. To confirm or rule out drug hypersensitivity, skin testing, in vitro studies, and challenge tests are necessary. However, the diagnostic value of this complex and time-consuming allergologic work-up, especially in children, remains controversial.

OBJECTIVE

Aim of this retrospective analysis was to compare the results of diagnostic testing in children and adolescents with drug hypersensitivity diagnosed on clinical grounds, i.e., temporal relationship and observation of symptoms alone.

METHODS

We studied 43 children and adolescents (23 females, 20 males, mean age 13) with a history of immediate or delayed hypersensitivity symptoms in temporal relation to drug treatment using standardized skin testing followed by oral challenges. Patients with suspected penicillin hypersensitivity were further evaluated with in vitro tests.

RESULTS

Drug hypersensitivity was excluded in 40 patients by tolerated oral challenge tests with the incriminated drug. In two patients, positive challenge tests confirmed non-steroidal anti-inflammatory drug hypersensitivity. One patient with amoxicillin-associated exanthema developed positive late skin test reactions to aminopenicillins.

CONCLUSION

In childhood and adolescence, allergologic testing in cases of suspected drug hypersensitivity is of importance both to establish a correct diagnosis and to prevent unjustified withholding of a drug or class of drugs.

Clinical manifestations and socio-economic impact of influenza among healthy children in the community

OBJECTIVES

To evaluate the total burden of influenza among healthy children in the community in order to analyse the cost of influenza in paediatric age.

METHODS

This prospective study involved a total community population of 21,986 children, 6988 of whom experienced an influenza-like illness (ILI) between 1 November 2008 and 30 April 2009. An electronic chart was completed, a nasopharyngeal swab was obtained, and information was recorded concerning the clinical outcomes and household impact of the ILI episodes. Influenza A and B viruses were detected in all the swabs by means of polymerase chain reaction, and costs of the disease were calculated.

RESULTS

Influenza viruses were detected in 2143 cases (30.7%), an incidence of 96.4 per 1000 children. Influenza A and B viruses were found in respectively 1751 (81.7%) and 392 cases (18.3%). The mean cost of influenza was no less than €130, 32% higher than the cost of influenza-negative ILIs (p < 0.001). The influenza A cases were significantly more expensive than the influenza B cases (p < 0.001), and influenza in children aged <2 and 2-5 years was significantly more expensive than in children aged >5 years (p < 0.05). The differences were mainly related to the indirect costs of the parents' lost working days.

CONCLUSIONS

The findings of this study confirm that influenza among healthy children is important because of its frequency and its indirect consequences on the households of infected children, and support the use of influenza vaccination in healthy children aged between 6 months and 5 years.

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.

Perceived adverse drug reactions among non-institutionalized children and adolescents in Germany

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Drug safety in paediatric medication is a public health concern. According to previous studies, the incidence of adverse drug reactions (ADRs) varies greatly from 0.7% to 2.7% among paediatric outpatients and from 2.6% to 18.1% among paediatric inpatients. Little has been reported on the risks of drug use in the general child population.

WHAT THIS STUDY ADDS

Our study showed that the prevalence of perceived ADRs in Germany was 0.9% among non-institutionalized children in general and 1.7% among children who had used at least one medicine within the 7 days before the medical interview. Perceived ADRs in the general child population were clustered with gastrointestinal disorders and subcutaneous tissue disorders. They appeared to be mild and at the lower limits of the range reported in other studies. Health surveys covering the use of a diverse range of drugs might be suitable for computing ADR prevalence and for identifying risk factors among non-institutionalized children. They should be taken into account together with other pharmacovigilance systems.

AIMS

Little has been reported on the risks of drug use in the general child population. This study investigated perceived adverse drug reactions (ADRs) among non-institutionalized children in Germany.

METHODS

All medicines used in the last 7 days before the medical interview were recorded among the 17 450 children aged 0-17 years who participated in the 2003-06 German Health Interview and Examination Survey for Children and Adolescents (KiGGS). Perceived ADRs were reported by the children's parents and confirmed by trained medical professionals during the medical interview.

RESULTS

One hundred and fifty-seven medicines were involved in the occurrence of 198 perceived ADRs in 153 patients. This corresponded to 1.1% of total used drugs, 0.9% (95% confidence intervals 0.7, 1.1%) of all children, and 1.7% (1.4, 2.1%) of children treated with medications. About 40% of all perceived ADRs involved gastrointestinal disorders and 16% involved skin tissue disorders. Perceived ADRs were most frequently reported in relation to drugs acting on the nervous system (25.8%), followed by systemic anti-infectives (18.7%) and drugs acting on the respiratory system (16.2%). Risk factors for perceived ADRs included older age groups, polypharmacy (>or=2) and a poor health status.

CONCLUSION

Perceived ADRs in the general child population were clustered with gastrointestinal disorders and subcutaneous tissue disorders. They appeared to be mild and at the lower limits of the range reported in other studies. Health surveys covering the use of a diverse range of drugs might be suitable for computing ADR prevalence and identifying risk factors among non-institutionalized children. They should be taken into account together with other pharmacovigilance systems.

Assessment of pediatric asthma drug use in three European countries; a TEDDY study

Asthma drugs are amongst the most frequently used drugs in childhood, but international comparisons on type and indication of use are lacking. The aim of this study was to describe asthma drug use in children with and without asthma in the Netherlands (NL), Italy (IT), and the United Kingdom (UK). We conducted a retrospective analysis of outpatient medical records of children 0-18 years from 1 January 2000 until 31 December 2005. For all children, prescription rates of asthma drugs were studied by country, age, asthma diagnosis, and off-label status. One-year prevalence rates were calculated per 100 children per patient-year (PY). The cohort consisted of 671,831 children of whom 49,442 had been diagnosed with asthma at any time during follow-up. ß2-mimetics and inhaled steroids were the most frequently prescribed asthma drug classes in NL (4.9 and 4.1/100 PY), the UK (8.7 and 5.3/100 PY) and IT (7.2 and 16.2/100 PY), respectively. Xanthines, anticholinergics, leukotriene receptor antagonists, and anti-allergics were prescribed in less than one child per 100 per year. In patients without asthma, ß2-mimetics were used most frequently. Country differences were highest for steroids, (Italy highest), and for ß2-mimetics (the UK highest). Off-label use was low, and most pronounced for ß2-mimetics in children <18 months (IT) and combined ß2-mimetics + anticholinergics in children <6 years (NL).

CONCLUSION

This study shows that among all asthma drugs, ß2-mimetics and inhaled steroids are most often used, also in children without asthma, and with large variability between countries. Linking multi-country databases allows us to study country specific pediatric drug use in a systematic manner without being hampered by methodological differences. This study underlines the potency of healthcare databases in rapidly providing data on pediatric drug use and possibly safety.

Allergic and Non-Allergic Drug Hypersensitivity Reactions in Children

Adverse drug reactions (ADR) are an important medical problem. The aim of this study is to investigate the clinical characteristics of children with ADR and to assess the tolerability of alternative drugs in children (under 16 yrs of age) with a history of ADR. We studied 278 children (132 males and 146 females). Patients were studied by recording personal history and performing in vivo skin testing, in vitro laboratory tests and challenge tests. Patients who had experienced mild adverse reactions underwent challenge tests without any premedication; patients with a clinical history of moderate reactions, received a premedication with sodium cromolyn 30 min before the oral challenge; patients with a clinical history of severe reactions or undergoing parenteral challenges, were given an antihistamine 30 minutes before. A total of 660 adverse events were reported with 126 different drugs involved. Antimicrobial agents were the most involved drugs (51.7%). Non-steroidal anti-inflammatory drugs were involved in 22.7% of episodes. The most reported symptoms were cutaneous. Allergy testing was negative in 272 patients. A diagnosis of drug allergy was reported for 6 patients. A total of 669 challenge tests were performed. 639 were negative at first attempt while 22 were positive. Eight were repeated using a different premedication and resulted negative. Hypersensitivity drug reactions in children are mainly non-allergic. A premedication with sodium cromolyn or with oral H1-antihistamines may be useful in preventing ADR.

Comparison of antiepileptic drug prescribing in children in three European countries

PURPOSE

Antiepileptic drug (AED) use in young people is increasing. However, evidence of its use at a multinational level is limited. This study aims to characterize AED prescribing in the young in three European countries and to assess the capacity of drug safety surveillance.

METHODS

A retrospective cohort study was conducted in 2001-2005 using primary care databases: PEDIANET (Italy, 0-11 years), IPCI (The Netherlands, 0-18 years), and IMS Disease Analyzer (United Kingdom, 0-18 years). Prescribing prevalence was calculated by country, patient age, and drug type.

RESULTS

In 2005, AED prevalence in children (0-11 years) was highest in Italy [3.9 subjects/1,000 person-years (PY)] followed by the United Kingdom (3.0 subjects/1,000 PY) and The Netherlands (2.2 subjects/1,000 PY). Over the study period, prescribing prevalence in 0-11 year olds was stable in all countries. In contrast, a steady rise of AED prevalence was observed in adolescents (12-18 years) in the United Kingdom (p = 0.0003) but not in The Netherlands (p = 0.88). All countries showed a slight increase in prevalence for newer AEDs. Simultaneously, the prevalence of conventional AEDs decreased in The Netherlands and Italy, but not in the United Kingdom. In 2005, lamotrigine use was highest in The Netherlands and the United Kingdom, whereas topiramate was favored in Italy.

DISCUSSION

In Europe, conventional AEDs are still the main treatment choice for children with epilepsy, and the use of newer AEDs remains low. Our study highlights a lack of research capacity to conduct multinational AED safety studies in children. Further work should explore large databases and other health care settings to meet these research needs.

Questionnaire-based survey of lifetime-prevalence and character of allergic drug reactions in German children

Data on the epidemiology of adverse drug reactions (ADR), especially allergic drug reactions, in children are rare. The reported prevalence of ADR in pediatric populations varies a lot, depending on type of the study and the country where the data were collected. In order to assess the prevalence of ADR and allergic drug reactions in a population of German children, we conducted a study in a German pediatric university hospital. A questionnaire concerning occurrence and character of ADR was distributed to all parents presenting their children in the hospital for planned admissions or in the emergency department from May 2004 to November 2004. Additional telephone interviews were conducted to specify the reported symptoms in ambiguous cases. One thousand four hundred forty-seven questionnaires were collected. The reported life-time prevalence of ADR according to the information given by the parents was 7.5% (108/1447). Six of the reactions were severe, three children had experienced anaphylactic reactions. In 4.2% (61/1447), the history was suspicious for a potential allergic mechanism because of an immediate or late phase cutaneous drug reaction. In this group, the suspected drugs were antibiotics in 85% (32.7% aminopenicillins, 29.5% other penicillins, 11.5% cefaclor, 8.2% macrolides and 18% others), antiphlogistic and respiratory drugs in 4.9% each and vaccines and contrast media in 3.3% each. There was a higher percentage of children under the age of four suffering from ADR. This trend was not significant when analyzing only the allergic reactions. Forty-four percent of the parents stated, their children suffer from drug allergy, although a clear non-allergic reaction was described. Both, ADR and allergic drug reactions are frequent phenomena in children. It is important to monitor drug therapy for any adverse reaction in order to inform the parents about the character of the adverse reaction, the necessary consequences and to initiate further diagnostic procedures.

Pediatric development of glucuronidation: the ontogeny of hepatic UGT1A4

This article reports on the development of UDP-glucuronosyltransferase (UGT) enzyme activity in pediatric livers. The substrates 4-methylumbelliferone (4MU) and trifluoperazine (TFP) were used as probes for general glucuronidation and specific UGT1A4 activity, respectively. The activity of hepatic beta-glucuronidase enzymes was also determined so as to investigate the balance between glucuronide clearance and systemic recirculation. UGT activity toward 4MU reached maximum levels by 20 months of age, whereas the activity of beta-glucuronidase was highest in the neonatal liver and decreased to steady-state adult levels by 4 months. The average V(max) and K(m) values for UGT1A4 in pediatric samples were 151.9 +/- 63.5 pmol/min/mg protein and 14.4 +/- 9.6 muM, respectively. Average V(max) was understandably low because of developmental dynamics, but K(m) was similar to values reported elsewhere. When a constant rate of enzyme development is assumed, maximum activity of UGT1A4 occurs at 1.4 years of age. When the intrinsic hepatic clearance of TFP was scaled with an allometric model, hepatic clearance of TFP by UGT1A4 did not reach maximum levels until 18.9 years of age and scaled results underestimated reported in vivo clearances in adult males. No significant differences in UGT activities or hepatic clearance were observed with gender or ethnicity. The developmental dynamics of most drug-metabolizing enzymes are unknown, and this article contains, to our knowledge, the first description of the development of a single UGT isoform in childhood. Ultimately, work such as this is important for predicting drug responses and for developing and evaluating new medications in children.

Incidence of mucocutaneous reactions in children treated with niflumic acid, other nonsteroidal antiinflammatory drugs, or nonopioid analgesics

BACKGROUND AND OBJECTIVE

Results from a relatively small case-control study recently showed that niflumic acid increases the risk of serious mucocutaneous reactions in children. As a consequence, the Italian Ministry of Health sent a "Dear Doctor" letter in June 2001 to warn pediatricians about the alleged adverse effects. The objective of this study was to estimate and compare the incidence of mild and severe mucocutaneous reactions among children using niflumic acid, other nonsteroidal antiinflammatory drugs (NSAIDs), or nonopioid analgesics.

DESIGN

Retrospective cohort study.

SETTING

Italy is one of the few countries in which a specific primary care system is devoted to children up to 14 years of age: every child is registered at birth and receives free medical care from 1 of the approximately 6000 family pediatricians working for the National Health Service. This study was conducted with the Pedianet network of Italian family pediatricians who use computerized electronic patient records for routine care; 185 pediatricians participated in the study. The patient records comprise information on demographics, diagnoses, symptoms, prescriptions, referrals, laboratory examinations, and hospitalizations.

PARTICIPANTS

Children aged 0 to 14 years and registered with 1 of the collaborating pediatricians between January 1, 1998, and May 31, 2001.

MAIN OUTCOME MEASURES

The incidence rate of severe (hospitalized or referred) and mild mucocutaneous reactions (exanthema, disseminated or localized pruritus, urticaria, angioedema, fixed eruption, dermatitis, erythema multiforme, vesicles, bullae, pustules, toxic epidermal necrolysis, purpura, and vasculitis) was estimated during use of niflumic acid, other NSAIDs, or nonopioid analgesics. For each episode of drug use, the following covariates were assessed: age, gender, region, year, indication for study drug, use of antibiotics, antimycotic agents, glucocorticoids, and other NSAIDs. Multivariate Poisson regression analysis was used to estimate the adjusted relative risk of mucocutaneous disorders during use of niflumic acid compared with use of other NSAIDs or use of acetaminophen alone.

RESULTS

The population included 193727 children, 45351 of whom received at least 1 of the study drugs. The most frequently prescribed drugs were niflumic acid, acetaminophen, and propionic acid derivatives (ketoprofen and flurbiprofen). Users of niflumic acid (n = 32150) were younger and slightly more often had otitis media or upper respiratory tract infections as an indication compared with the other NSAIDs. During use of the various study drugs we identified 1451 mild mucocutaneous events and 42 severe reactions. The incidence rates of severe and mild mucocutaneous reactions after the administration of any study drug were 10.3 per 100000 exposure person-days and 3.7 per 1000 exposure person-days, respectively. Both incidence rates decreased strongly with increasing age. In comparison with other NSAIDs, the adjusted relative risks of niflumic acid were 0.5 (95% confidence interval: 0.23-1.27) for severe and 0.9 (95% confidence interval: 0.79-1.11) for mild mucocutaneous reactions. The use of acetaminophen as a reference category instead of other NSAIDs, restriction of the children to those who received NSAIDs for respiratory tract infections, or restriction to those who did not use antibiotics never revealed an increased risk of serious or mild mucocutaneous reactions during use of niflumic acid.

CONCLUSIONS

In comparison with other NSAIDs or acetaminophen, niflumic acid is not associated with an increased risk of severe or mild mucocutaneous reactions in children. This was true for the different age groups and various types of mucocutaneous reactions, was independent of the concomitant use of antibiotics, and was not sensitive to changes in our assumptions regarding exposure and outcomes.

Reações adversas a medicamentos em pediatria: uma revisão sistemática de estudos prospectivos

O objetivo desta revisão foi explorar e comparar as informações derivadas de estudos prospectivos sobre a incidência de reações adversas a medicamentos (RAM) em pediatria, publicados de janeiro de 1966 a novembro de 2003 em revistas indexadas nas bases MEDLINE, IPA e LILACS. Foram buscados trabalhos que abordassem a ocorrência de RAM em crianças atendidas em ambulatório, durante a hospitalização ou como causa de internação hospitalar não focalizados em tratamentos ou condições clínicas específicas. A análise incluiu vinte estudos de coorte prospectivos, entre os quais a incidência de RAM variou de 0,75% a 11,1% em ambulatório, de 0,6 a 4,3% como causa de internação hospitalar e de 4,4 a 18,1% entre crianças hospitalizadas. O trabalho ressalta o potencial de contribuição dos estudos prospectivos para o uso seguro de medicamentos em pediatria e sugere que a padronização de definições e de critérios metodológicos poderia torná-los mais úteis para esse objetivo.

Reported adverse drug reactions and their determinants in Dutch children outside the hospital

PURPOSE

The interpretation of the available studies on adverse drug reactions (ADRs) in children outside the hospital is hampered because none of these studies used a control group. The aim of this study was to describe ADRs in children outside the hospital, controlled for drug use in the paediatric background population.

METHODS

Using a case-control design, we compared drugs on which a suspected ADR was reported to the Netherlands Pharmacovigilance Centre LAREB, and drugs used in the general paediatric population from the InterAction pharmacy database, both in the year 2001, for children aged 0-16 years.

RESULTS

The main findings are that ADRs were disproportionately more often reported on systemic drugs (OR 3.0; [95%CI: 1.9-4.8]), new drugs (2.4; [1.6-2.7]), anti-infective drugs (1.7; [1.1-2.7]) and nervous system drugs (2.1; [1.3-3.5]), whereas unlicensed drugs (0.1; [0.0-0.4]), frequently used drugs (0.3; [0.2-0.5]) and dermatologicals (0.1; [0.0-0.4]) were less likely to be associated with a reported ADR. Overall, the proportion of off-label prescriptions did not differ between drugs suspected of an ADR and drugs used by children in a general population.

CONCLUSIONS

The pattern of drugs associated with a reported ADR could not be solely explained on the basis of drug utilisation patterns in the general population.

Widespread off-label prescribing of topical but not systemic drugs for 350,000 paediatric outpatients in Stockholm

OBJECTIVES

Many hospital-based studies throughout Europe have shown that a substantial number of children receive off-label prescribed drugs that lack marketing authorisation for paediatric use. Since information about the extent and characteristics of this prescribing pattern in paediatric primary health care is limited, we assessed the proportion of off-label drug prescribing for paediatric outpatients in a reference population of 350,000 children using a computerised prescription database. We also determined the adherence to a treatment guideline provided by the Stockholm county council as a quality of prescribing indicator.

METHODS

All drugs prescribed for children younger than 16 years of age in the Stockholm county in the year 2000 were ranked by the number of prescription items. The retrospective, descriptive analysis was restricted to those drugs that accounted for 90% of total prescribing. We calculated the proportion of off-label drug prescribing for different age and therapeutic groups with respect to age, formulation and route of administration using the Swedish Physician's Desk Reference. The quality of prescribing was estimated as the proportion of prescription items corresponding to recommended drugs in the local treatment guideline Kloka Listan (The Wise List).

RESULTS

Among the 317 drugs accounting for 90% of total prescribing, 575,526 prescription items were identified with an average proportion of off-label and recommended drug prescribing of 20.7% and 60.5%, respectively. The off-label proportion was similar in various age groups but widely different between therapeutic groups being much higher for topical (70.4%) than for systemic (5.4%) drugs. The extent to which recommended drugs were prescribed also greatly varied between therapeutic groups irrespectively of the off-label proportion.

CONCLUSIONS

Off-label drug prescribing for paediatric outpatients is a common phenomenon. However, it mainly applied to topical drugs and was to a substantial extent recommended by the local treatment guideline. Thus, off-label prescribing might represent a more administrative rather than clinical problem in the paediatric outpatient setting.

The incidence of varicella: correction of a common error

BACKGROUND

Interest in the incidence of varicella (chickenpox) has increased since the discovery of an effective vaccine, but calculations to date have incorrectedly ignored the question of susceptibility.

METHODS

We studied the occurrence of varicella in Italy on the basis of 33,343 children (age 0-14 years) cared for by 35 pediatricians between 1 October 1997 and 30 September 1998. The life-table technique was used to calculate the number of susceptible children. On this basis, we estimated the corrected age-specific and cumulative incidence.

RESULTS

We identified 1749 cases among the estimated 21,783 susceptible children, for a crude incidence of 8.0% (95% confidence interval [CI] = 7.7-8.4). The rate age-standardized to the Italian population 0-14 years old was 6.8 (CI = 6.5-7.2). The incidence was more than 16% among children age 3-4 years and more than 4% for those age 1-10 years. Comparison of the usual method and our corrected method showed that the uncorrected method underestimates the crude annual incidence (5.2% 8.0%), shifts the peak incidence to earlier ages, and underestimates cumulative incidence (at age 14, 49% 67%).

CONCLUSIONS

The use of our corrected method provides more valid estimates of the incidence of varicella than the ones that are currently available. Corrected estimates should be preferred to uncorrected ones in models to study the cost-effectiveness of universal vaccination against varicella.

Adverse drug reactions and off-label drug use in paediatric outpatients

AIMS

To investigate the potential relationship between off-label drug use and increased risk of adverse drug reactions in paediatric outpatients.

METHODS

A prospective pharmacovigilance survey of drug prescribing in office based paediatricians was carried out in Haute-Garonne County (south west of France).

RESULTS

The study involved a sample of 1419 children under 16 years old. Forty-two percent of patients were exposed to at least one off-label prescription. The incidence of adverse drug reactions was 1.41% (95% CI 0.79, 2.11). Off-label drug use was significantly associated with adverse drug reactions (relative risk 3.44; 95% CI 1.26, 9.38), particularly when it was due to an indication different than that defined in the Summary Product Characteristics (relative risk 4.42; 95% CI 1.60, 12.25).

CONCLUSIONS

Our data suggest an increasing risk of adverse drug reactions related to off-label drug use. This risk would be acceptable if further studies prove the potential benefit of such a drug use.

Frequency of adverse drug reactions in children: a prospective study

AIMS

To assess the frequency of adverse drug reactions (ADRs) in children in France.

METHODS

In a prospective study over a period of 1 week, we evaluated the incidence of ADRs (1) as a cause of admission to a regional children's hospital; (2) occurring during hospitalization in a regional children's hospital; and (3) as a cause of consultation with private paediatricians.

RESULTS

Four out of 260 children were admitted to the regional children's hospital for ADRs (1.53% [0.42, 3.89]) and six developed ADRs during hospitalization (2.64% [0.97, 5.66]), 4/428 attended the Accident and Emergency Department for ADRs (0.93% [0.25, 2.37]) and 8/1192 consulted a private paediatrician for ADRs (0.67% [0.29, 1.31]).

CONCLUSIONS

Our results are in agreement with the incidence of ADRs in children found in others countries.

Incidence of adverse drug reactions in paediatric in/out-patients: a systematic review and meta-analysis of prospective studies

AIMS

To explore the usefulness of data derived from observational studies on adverse drug reactions (ADRs) in defining and preventing the risk of pharmacological interventions in children in different health care settings.

METHODS

A systematic review of studies on ADRs in hospitalized children, in outpatient children, and on ADRs causing paediatric hospital admissions was performed. Studies were identified through a search of the MEDLINE and EMBASE databases. The inclusion criteria required that the population was not selected for particular conditions or drug exposure and prospective monitoring was used for identifying ADRs. Data were analysed by a random-effects model.

RESULTS

Seventeen prospective studies were included. In hospitalized children, the overall incidence of ADRs was 9.53% (95% confidence interval [CI], 6.81, 12.26); severe reactions accounted for 12.29% (95%CI, 8.43,16.17) of the total. The overall rate of paediatric hospital admissions due to ADRs was 2.09% (95%CI, 1.02, 3.77); 39.3% (95%CI, 30.7,47.9) of the ADRs causing hospital admissions were life threatening reactions. For outpatient children the overall incidence of ADRs was 1.46% (95%CI, 0.7, 3.03).

CONCLUSIONS

The results show that ADRs in children are a significant public health issue. The completeness and accuracy of prescription reporting as well as clinical information from studies was a rarity, making it difficult for health practitioners to implement evidence based preventive strategies. Further, methodologically sound drug surveillance studies are necessary for an effective promotion of a safer use of drugs in children.

ADR Monitoring in Children; Pancytopenia and Valproic Acid: A Dose-Related Phenomenon; Asterixis with Lithium Therapy?; Splenic Rupture Due to Subcutaneous Heparin; EPS on Clozapine?

The purpose of this feature is to heighten awareness of specific adverse drug reactions (ADRs), to discuss methods of prevention, and to promote reporting of ADRs to the FDA's medWatch program (1-800-FDA-1088). If you have reported an interesting preventable ADR to medWatch, please consider sharing the account with our readers.