Suspected adverse drug reaction reports with oral anticoagulants in Portugal: a pharmacovigilance study

Objective: In this pharmacovigilance study, we aimed to determine the incidence of spontaneously reported suspected adverse drug reactions (ADRs) related to oral anticoagulants: non-vitamin K antagonist oral anticoagulants (NOACs; apixaban, dabigatran, edoxaban, rivaroxaban) and vitamin K antagonists (VKA)

Research design and methods: In this retrospective observational study, we extracted all the individual case safety reports related to oral anticoagulants recorded in the Portuguese Pharmacovigilance Database (January 2010 to April 2015). The annual incidence of suspected ADRs was estimated using drug exposure data. Disproportionality of reporting ADR was addressed through reporting odds ratio (ROR) and 99% confidence intervals.

Results: We appraised 794 suspected ADR (78% related to NOACs). The annual number of ADRs increased overtime with 9 ADRs/million Defined Daily Dose (DDD) at the end of 2014. The incidence of NOACs ADRs decreased from 2012 onwards. VKA showed a disproportion in ‘Investigation’ (ROR 0.10, 99%CI 0.05–0.22) and ‘Injury, poisoning and procedural complications’ (ROR 0.36, 99%CI 0.19–0.69) ADRs compared with NOACs. NOACs had a higher significant disproportion of ‘Nervous system disorders’ related ADRs (ROR 3.98, 99%CI 1.50–10.53).

Conclusions: Reporting of ADRs associated with oral anticoagulants (mainly NOACs), is increasing. Exploratory disproportion analyses showed an increase of reports of nervous system ADRs with NOACs, and INR-related ADRs with VKA.     

Adverse drug reactions in Ghanaian children: review of reports from 2000 to 2012 in VigiBase

Objective: The aim of this article is to describe adverse drug reactions (ADRs) reported for children aged 0 – 17 years in Ghana.

Methods: Paediatric reports submitted by the Ghana National Centre for Pharmacovigilance to the World Health Organisation (WHO) Global ADR database, VigiBase up to December 2012 were extracted. The data were analysed for number of reports per year, types of reporters and suspected ADRs and drugs.

Results: A total of 343 reports for children were received during the period. The drug classes most frequently reported were vaccines (115, 31%), antimalarials (106, 28%) and antibiotics (57, 15%). Of the top 20 individual drugs, 19 were anti-infectives. The most frequently reported ADRs were injection site infection, fever and rash. There were 23 deaths reported, and antimalarials were implicated in 12 cases.

Conclusions: Vaccines, antimalarials and antibiotics are the leading medicines reported to cause ADRs in Ghanaian children. There was a high mortality rate, with many of the deaths due to causes explained in the individual case safety reports.     

Suspected adverse reactions to contrast media in Campania Region (Italy): results from 14 years of post-marketing surveillance

Objective: During the last years in Italy, contrast media (CM) use increased. An increase of monitoring activities on CM-induced adverse drug reaction (ADR) is necessary, also in our regional territory. The main aim of this study was to give a preliminary evaluation of all Spontaneous Reports of ADRs (SRA) attributed to CM sent to Campania Pharmacovigilance Regional Center (CRFVC) from 01 January 2001 to 31 October 2014.

Research design and methods: For each SRA we evaluated: frequency and source, ADRs onset (time to event, seriousness and outcome), socio-demographic characteristics and risk factors of cases, the most reported CM (checking for pharmacodynamic and pharmacokinetic interactions).

Results: A total of 111 SRA were sent to CRFVC; specialist in radiology was the main source of reports. Ninety-seven SRA (87.3%) were referable to hypersensitivity reactions. Thirty-four SRA (30.6%) reported serious ADRs. The most reported CM were iopamidol, gadobenic acid and gadoteric acid. We identified two SRA induced by pharmacokinetic and/or pharmacodynamic interactions.

Conclusions: During 14 years of post-marketing surveillance, only few SRA concerning CM-induced ADRs were sent to CRFVC probably due to underreporting. We aim to improve monitoring activity on CM-induced ADRs especially in hospitals. Most reported ADR and CM were in line with current body of literature.     

Preventable ADRs leading to hospitalization — results of a long-term prospective safety study with 6,427 ADR cases focusing on elderly patients

Background: Studies evaluating the impact of age and potentially inappropriate medication (PIM) on avoidable adverse drug reactions (ADRs) are scarce.

Methods: In this prospective, multi-center, long-term (8.5 years) observational study, we analysed ADRs leading to hospitalization in departments of internal medicine. ADRs causality and preventability were assessed using standardised algorithms. PIM was defined based on the PRISCUS-list. Multivariate analyses and estimation of ADR incidence rates were conducted.

Results: Of all 6,427 ADR patients, a preventable ADR was present in 1,253 (19.5%) patients (elderly patients ≥70 years: 828). Risk factors for preventable ADRs in elderly patients were multimorbidity, two to four ADR-causative drugs, and intake of particular compounds (e.g. spironolactone) but not sex, PIM usage, or the total number of drugs. Regarding particular compounds associated with preventable ADRs, highest incidence rates for preventable ADRs were found for patients aged ≥70 years for spironolactone (3.3 per 1,000 exposed persons (95% CI: 1.4–6.6)) and intermediate-acting insulin (3.3 per 1,000 exposed persons (95% CI: 1.6–6.1)).

Conclusion: Avoiding PIM usage seems to be of limited value in increasing safety in elderly patients whereas our results underline the importance of an individualized medication review of the most commonly implicated drugs in preventable ADRs (supported by BfArM FoNr: V-11337/68605/2008–2010).     

Evaluating Twitter as a complementary data source for pharmacovigilance

Background: Social media are currently considered as a potential complementary source of knowledge for drug safety surveillance. Our primary objective was to estimate the frequency of adverse drug reactions (ADRs) experienced by Twitter users. Our secondary objective was to determine whether tweets constitute a valuable and informative source of data for pharmacovigilance purposes, despite limitations on character number per tweet.

Research design and methods: We selected a list of 33 drugs subject to careful monitoring due to safety concern in France and Europe, and extracted tweets using the streaming API from 30 September 2014 to 5 April 2015. Two pharmacovigilance centers classified these tweets manually as potential ADR case reports.

Results: Among 10,534 tweets, 848 (8.05%) implied or mentioned an ADR without meeting the four FDA criteria required for reporting an ADR, and 289 (2.74%) tweets were classified as ‘case reports.’ Among them 20 (7.27%) tweets mentioned an unexpected ADR and 33 (11.42%) tweets mentioned a serious ADR.

Conclusions: With the use of dedicated tools, Twitter could become a complementary source of information for pharmacovigilance, despite a major limitation regarding causality assessment of ADRs in individual tweets, which may improve with the new limitation to 280 characters per tweet.     

The economic burden of preventable adverse drug reactions: a systematic review of observational studies

Introduction: Adverse drug reactions (ADRs) are an important cause of morbidity and mortality worldwide. They are associated with healthcare costs due to hospital admissions or prolonged length of stay, as well as additional interventions. The aim of this study was to conduct a systematic review of observational studies to evaluate the economic impact of preventable ADRs.

Areas covered: Published observational research investigating the cost of preventable ADRs in Western countries (limited to the USA and European countries).

Expert opinion: Several reviews have been carried out in the field of the ADR epidemiology but fewer reviews have investigated the economic impact of ADRs, and at the time of writing, none has focused on preventable ADRs. The reason why future research should focus on the costs of preventable ADRs is that both the costs and the negative clinical outcomes are preventable, and as such, are a key point of public health policy action. Nevertheless, the present review highlights an important and sobering limitation of published research on the cost of preventable ADRs, of which the major limitation is the heterogeneity in methods and in reporting which limit what can be known through the summarizing work of a systematic review.     

Adverse drug reactions in children: a ten-year review of reporting to the Portuguese Pharmacovigilance System

Objective: Adverse drug reactions (ADR) are a public health problem. They cause significant morbidity, mortality and health costs. Less is known about pediatric ADR. Our goal was to characterize a pediatric case series of ADR reported to the Portuguese Pharmacovigilance System (PPS) during the past 10 years.

Research design and methods: Retrospective analysis of ADR reports concerning patients till 17 years old received by the PPS between 2003 and 2012. We evaluated patients’ demographic data and involved drugs, as well as characteristics and seriousness of reactions, stratified by age groups.

Results: We found 1742 reports (50% females) corresponding to 9.7% of the total received. The age of the patients varied from 0 to 17 years (median: 5 years, interquartile range: 10.6), with 566 cases (32%) occurring in patients younger than 2y. Among the 1195 serious cases, 31% (370) episodes led to hospitalization. In 32 cases (2%) there was a fatal outcome. Most of the ADR reported referred to general disorders and administration site conditions, followed by skin and subcutaneous tissue reactions. Vaccines were the most represented group (42%) followed by antibacterials for systemic use (17%).

Conclusions: Pediatric ADR represents about 10% of the reports received by the PPS. Most ADR were considered serious. Major findings varied according to age groups.     

First experiences with a tool to measure the level of clinical information present in adverse drug reaction reports

Background: To make a proper causality assessment of an adverse drug reaction (ADR) report, a certain level of clinical information is necessary. A tool was developed to measure the level of clinical information present in ADR reports. The aim of this study was to test the validity and reliability of the clinical documentation tool (ClinDoc) in an international setting.

Methods: The tool was developed by a panel of pharmacovigilance experts. It includes four domains: ADR, chronology of the ADR, suspected drug and patient characteristics. The final score categorizes reports into: excellent, well, moderately or poorly documented.

In two rounds, eight pharmacovigilance assessors of different countries made a total of 224 assessments using the tool, with the expert panels judgement as a standard. Sensitivity and specificity were calculated.

Results: The tool with four outcome-categories demonstrated low sensitivity. A lack of distinctiveness was demonstrated between the categories moderate and well. Results for the second round were re-analysed using three categories. This demonstrated a better validity.

Conclusion: This is the first tool to give insight in the level of relevant clinical information present in ADR reports. It can be used internationally to compare reports coming from different reporting methods and different types of reporters in pharmacovigilance.     

Exploiting heterogeneous publicly available data sources for drug safety surveillance: computational framework and case studies

Objective: Driven by the need of pharmacovigilance centres and companies to routinely collect and review all available data about adverse drug reactions (ADRs) and adverse events of interest, we introduce and validate a computational framework exploiting dominant as well as emerging publicly available data sources for drug safety surveillance.

Methods: Our approach relies on appropriate query formulation for data acquisition and subsequent filtering, transformation and joint visualization of the obtained data. We acquired data from the FDA Adverse Event Reporting System (FAERS), PubMed and Twitter. In order to assess the validity and the robustness of the approach, we elaborated on two important case studies, namely, clozapine-induced cardiomyopathy/myocarditis versus haloperidol-induced cardiomyopathy/myocarditis, and apixaban-induced cerebral hemorrhage.

Results: The analysis of the obtained data provided interesting insights (identification of potential patient and health-care professional experiences regarding ADRs in Twitter, information/arguments against an ADR existence across all sources), while illustrating the benefits (complementing data from multiple sources to strengthen/confirm evidence) and the underlying challenges (selecting search terms, data presentation) of exploiting heterogeneous information sources, thereby advocating the need for the proposed framework.

Conclusions: This work contributes in establishing a continuous learning system for drug safety surveillance by exploiting heterogeneous publicly available data sources via appropriate support tools.     

Feedback for patients reporting adverse drug reactions; satisfaction and expectations

Objective: Due to the rising number of patient reports in pharmacovigilance, the manner in which feedback is provided to patients is an element to be considered. The objective is to explore the satisfaction of patients towards personalized and general feedback in response to their reported adverse drug reactions (ADRs).

Methods: Patients who reported an ADR to the Dutch Pharmacovigilance Centre for the first time in the period between October 2012 and April 2013 were included. Reporters received personalized feedback or a general acknowledgement letter. Satisfaction towards the received feedback, expressed on a 5-point Likert scale (1 very good to 5 very poor), was studied using a web-based questionnaire. Data were analyzed using Pearson Chi-square test and linear regression analysis. Statistical significance was based on p < 0.05.

Results: A total of 471 patient-reporters were contacted with a total response of 52.5%. Respondents of both groups were satisfied with the received feedback, average score 2 (good). Respondents of the personalized feedback-group were however more satisfied score 2.0 versus 2.5 (p < 0.001) and considered the feedback more clear and useful compared with respondents of the acknowledgement letter-group, respectively score 1.6 versus 1.7 (p = 0.01) and score 2.1 versus 2.5 (p < 0.001).

Conclusion: Patients reporting ADRs are satisfied with feedback received from the pharmacovigilance centre, whether this is a personalized feedback or a general acknowledgment letter. They find it clear, useful and it meets their expectation. Although differences were found between the two types of feedback, these differences did not indicate dissatisfaction towards the received feedback.     

Preventable statin adverse reactions and therapy discontinuation. What can we learn from the spontaneous reporting system?

Background: Statin treatment is often associated with poor adherence, which may be due to the onset of adverse drug reactions (ADRs). We investigated on potential risk factors related to preventable cases of statin-induced ADRs and to the discontinuation of statin therapy.

Methods: We performed a study using the database of Italian spontaneous reporting. The target population for the preventability assessment was all patients with suspected statin-induced ADRs deriving from Campania Region (a territory of Southern Italy) between 2012 and 2017. Additionally, a local sentinel surveillance site involving General Practitioners was selected to countercheck in routine clinical practice the role of ADRs for statin discontinuation.

Results: In total, 34 of 655 (5.19%) regional cases were preventable and among detected risk factors 90.0% was related to healthcare professionals’ practices and 10.0% to patient behaviour. In 81.4% (533/655) of cases, statin therapy was discontinued due to ADRs, mainly classified as not serious and associated with a positive prognosis. These results were also confirmed in the active sentinel site.

Conclusions: Our findings suggest an inappropriate use of statins among the identified preventable cases and a potential inappropriate statin discontinuation due to ADRs. These factors may be useful for targeting interventions to improve statin adherence.     

Taurine reduces blue light-induced retinal neuronal cell apoptosis in vitro

Background: The massive uptake of organic compatible osmolytes is a self-protective response to multiple stressors.

Objective: This study aimed to determine the protective effects of the osmolyte taurine against blue light-induced apoptosis in retinal neuronal cells in vitro.

Methods: Real-time PCR was used to measure osmolyte transport. Radioimmunoassays were performed to measure osmolyte uptake. Cell Counting Kit-8 assays were conducted to measure cellular viability. Flow cytometry analysis was used to measure apoptosis.

Results: Compared with normotonic stress, hypertonic stress-induced uptake of osmolytes, including betaine, myoinositol, and taurine, into the retinal neuronal cells. Blue light increased osmolyte transporter mRNA expression together with osmolyte uptake. Furthermore, taurine significantly suppressed blue light-induced retinal neuronal cell apoptosis.

Conclusion: The compatible osmolyte taurine may have an important role in cell resistance to blue light and cell survival.     

Inhibitors of α-glucosidase and α-amylase from Cyperus rotundus

Context: A methanol extract of Cyperus rotundus L. (Cyperaceae) rhizomes showed inhibitory activity against α-glucosidase and α-amylase, two enzymes involve in carbohydrate digestion.

Objective: Identification of compounds from C. rotundus rhizomes responsible for the inhibition of α-glucosidase and α-amylase.

Materials and methods: Compounds were identified by a phytochemical investigation using combined chromatographic and spectroscopic methods. α-glucosidase and α-amylase inhibitory activities were evaluated by in vitro enzyme inhibition assays.

Results: A new (2RS,3SR)-3,4′,5,6,7,8-hexahydroxyflavane (1), together with three known stilbene dimers cassigarol E (2), scirpusin A (3) and B (4) were isolated. Compound 2 inhibited both α-glucosidase and α-amylase activities while the flavane 1 only showed effect on α-amylase, and compounds 3 and 4 were active on α-glucosidase. All four compounds showed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity.

Discussion: The inhibitory activities against α-amylase and α-glucosidase of the C. rotundus rhizomes were reported for the first time. Stilbene dimers are considered as potent inhibitors of α-glucosidase and promising antihyperglycemic agents.

Conclusion: The isolated compounds may contribute to the antidiabetic property of C. rotundus.     

A review on phytochemical and pharmacological properties of Litsea coreana

Context: Litsea coreana H. Lév. (Lauraceae) is used as an ethnic herb or beverage in China. Substantial studies indicate that it contains a variety of compounds and shows diverse bioactivities with no toxicity.

Objective: This review analyzes and summarizes the ethnopharmacological applications, phytochemistry, and pharmacological activities and molecular mechanisms of L. coreana.

Methods: Related literature (from 1998 to 2016) was obtained and compiled via searching databases including Scopus, Web of Science, Google Scholar, CNKI and PubMed. Keywords (Litsea coreana, hawk tea, eagle tea and laoying cha) were used to select the articles.

Results: Studies indicate that L. coreana contains characteristic polysaccharides, polyphenols, essential oils, and numerious flavonoids, which exhibit remarkable bioactivities, such as hepatoprotection, hyperglycaemia, anti-inflammation, antioxidation and antibacterial, through multiple molecular mechanisms.

Conclusion: This paper provides a systematic review on the phytochemicals and pharmacological activities of L. coreana which should be useful for further study and application of this medicinal herb.     

Medicinal plants and natural products in amelioration of arsenic toxicity: a short review

Context: Chronic arsenic toxicity (arsenicosis) is considered a serious public health menace worldwide, as there is no specific, safe, and efficacious therapeutic management of arsenicosis.

Objectives: To collate the studies on medicinal plants and natural products with arsenic toxicity ameliorative effect, active pre-clinically and/or clinically.

Methods: Literature survey was carried out by using Google, Scholar Google and Pub-Med. Only the scientific journal articles found on the internet for last two decades were considered. Minerals and semi-synthetic or synthetic analogs of natural products were excluded.

Results: Literature study revealed that 34 medicinal plants and 14 natural products exhibited significant protection from arsenic toxicity, mostly in preclinical trials and a few in clinical studies.

Conclusion: This research could lead to development of a potentially useful agent in clinical management of arsenicosis in humans.     

Potential roles of myeloperoxidase and hypochlorous acid in metabolism and toxicity of alkene hydrocarbons and drug molecules containing olefinic moieties

Introduction: Adverse drug reactions (ADRs) pose a significant health problem and are generally attributed to reactive metabolites. Olefinic moieties in drugs can undergo cytochrome P450-mediated bioactivation to produce reactive metabolites but myeloperoxidase (MPO)-mediated bioactivation of these moieties has not been reported. Thus, small molecules of alkene hydrocarbons are used as model compounds to characterize the MPO-mediated metabolism.

Areas covered: The authors focus on MPO-mediated metabolism of alkene hydrocarbons to form chlorohydrins and the potential role of chlorohydrins in alkene toxicity and carcinogenicity. A case study is presented, in which a carcinogenic alkene, 1,3-butadiene, is demonstrated to form 1-chloro-2-hydroxy-3-butene (CHB) through the MPO-mediated pathway. Further bioactivation of CHB yields a cross-linking metabolite, 1-chloro-3-buten-2-one (CBO), which is highly reactive toward glutathione, proteins, nucleosides, and DNA. Toxicity and mutagenicity of CHB and CBO are also presented.

Expert opinion: Alkene hydrocarbons readily undergo MPO-mediated bioactivation to form chlorohydrins, which can further be biotransformed into proteins/DNA-modifying reactive metabolites. Therefore, chlorohydrin formation may play an important role in alkene toxicity and carcinogenicity. Olefinic moieties in drugs are expected to undergo similar bioactivation, which may contribute to ADRs. Studies to investigate the roles of MPO and chlorohydrin formation in ADRs are thus warranted.