Adverse drug reactions and their fatal outcomes in clozapine patients in VigiBase: Comparing the top four reporting countries (US, UK, Canada and Australia)

BACKGROUND

Pharmacovigilance findings and box warnings in the clozapine package inserts have marked the history of clozapine.

OBJECTIVE

This is the largest review of clozapine adverse drug reactions (ADRs) and their associated fatal outcomes. Reports to the World Health Organization's global pharmacovigilance database, VigiBase™, were analyzed, extending from clozapine's introduction to December 31, 2022.

METHODS

The analysis focused on the top four reporting countries: United States (US), United Kingdom (UK), Canada and Australia (83 % of fatal outcomes worldwide). Attempts were made to control for population and clozapine prescription in each country.

RESULTS

Clozapine ADRs worldwide accounted for 191,557 reports, with the highest number (53,505) in "blood and lymphatic system disorder". Of the 22,596 fatal outcomes reported in clozapine patients, 9587 were from the US, 6567 from the UK, 3623 from Canada and 1484 from Australia. The top category worldwide in fatal outcomes was nonspecifically labeled "death" with 46 % (range 22-62 %). "Pneumonia" was second with 30 % (range 17-45 %). Agranulocytosis was numerically only the 35th top clozapine ADR associated with fatal outcomes. On average, 2.3 clozapine ADRs were reported per fatal outcome. Infections were associated with 24.2 % of the UK fatal outcomes (9.4 %-11.9 % in the 3 other countries).

CONCLUSIONS

The four countries appeared to report clozapine ADRs in different ways, making comparisons difficult. We estimated higher fatal outcomes in the UK and Canada after controlling for cross-sectional estimations of population and published clozapine use. This last hypothesis is limited by the lack of precise estimation of accumulated clozapine use in each country.

Using Failure Mode, Effect and Criticality Analysis to improve safety in the cancer treatment prescription and administration process

BACKGROUND

Administering cancer drugs is a high-risk process, and mistakes can have fatal consequences. Failure Mode, Effect and Criticality Analysis (FMECA) is a widely recognized method for identifying and preventing potential risks, applied in various settings, including healthcare. The aim of this study was to recognize potential failures in cancer treatment prescription and administration, with a view to enabling the adoption of measures to prevent them.

METHODS

This study consists of a FMECA. A team of resident doctors in public health at the University of Padua examined the cancer chemotherapy process with the support of a multidisciplinary team from the Veneto Institute of Oncology (an acknowledged comprehensive cancer center), and two other provincial hospitals. A diagram was drafted to illustrate 9 different phases of chemotherapy, from the adoption of a treatment plan to its administration, and to identify all possible failure modes. Criticality was ascertained by rating severity, frequency and likelihood of a failure being detected, using adapted versions of already published scales. Safety strategies were identified and summarized.

RESULTS

Twenty-two failure modes came to light, distributed over the various phases of the cancer treatment process, and seven of them were classified as high risk. All phases of the cancer chemotherapy process were defined as potentially critical and at least one action was identified for a single high-risk failure mode. To reduce the likelihood of the cause, or to improve the chances of a failure mode being detected, a total of 10 recommendations have been identified.

CONCLUSIONS

FMECA can be useful for identifying potential failures in a process considered to be at high risk. Safety strategies were devised for each high-risk failure mode identified.

Drug-Related Deaths in China: An Analysis of a Spontaneous Reporting System

Background: Adverse drug reactions with an outcome of death represent the most serious consequences and are inherently important for pharmacovigilance. The nature and characteristics of drug-related deaths are to a large extent unknown in the Chinese population. This study aims to characterize drug-related deaths by analysis of individual case safety reports (ICSRs) with an outcome of death in China.

Methods: The characteristics of death ICSRs were analyzed by descriptive statistics of a large multi-provincial pharmacovigilance database in China.

Results: There were 1,731 ICSRs with an outcome of death, representing 0.95% of all serious cases and 0.05% of all reported ICSRs. Most death ICSRs (78.57%) were reported by medical institutions. Only 16.00% of death ICSRs were reported by manufacturers or distributors. The reporting rate of death ICSRs in the age group of 0–4 years was significantly higher than patients aged 5–64 years. Patients aged over 64 years had the highest reporting rate of death ICSRs. Male patients generally had a higher reporting rate of death ICSRs than female patients. However, the reporting rate of female patients exceeded that of male patients in the age group of 20–34 years. Among 3,861 drugs implicated, ceftriaxone sodium with 146 (3.78%) records of death ranked first. Dexamethasone with 131 (3.39%) records of death ranked second. Qingkailing, an injectable traditional Chinese medicine with 75 (1.94%) records of death, ranked the fifth most frequently implicated medicine.

Conclusion: Young children and elderly patients have a higher risk of drug-related deaths than patients aged 5–64 years. Female patients generally have a lower risk of drug-related deaths than male patients. However, female patients of reproductive age (aged 20–34 years) have a higher risk of drug-related deaths than male patients, hinting that physiological changes and drug uses for child bearing, giving birth, or birth control may significantly increase the risk of death for female patients aged 20–34 years. This paper suggests more research on the safe use of drugs for young children, elderly patients, and female patients of reproductive ages. Pharmacovigilance databases can be valuable resources for comprehensive understanding of drug-related problems.

Fatal Events Associated with Adverse Drug Reactions in the Korean National Pharmacovigilance Database

Adverse drug reactions (ADRs) pose a global public health threat, substantially contributing to death. Due to the relative paucity of clinical evidence regarding fatal ADRs, this study was performed to characterize the epidemiology of fatal ADRs in Korea. This was a retrospective, cross-sectional analysis of ADR cases reported to the Korea Adverse Event Reporting System from 2010 to 2019. All ADRs were coded using the World Health Organization-Adverse Reaction Terminology system and classified as either fatal or non-fatal events. Logistic regression was performed to identify factors associated with fatal events. Among 289,756 ADR records, 629 fatal events (0.2%) occurred. The most common causative agent of fatal ADRs was antibacterials (20.3%), followed by antimycobacterials (5.4%), analgesics (4.0%), and contrast media (1.9%). Among antimicrobials, vancomycin was most frequently implicated without significantly increasing the risk of fatal events. The risk for fatal ADRs was significantly increased with male sex; advanced age; polypharmacy; piperacillin/β-lactamase inhibitor; cefotetan; ceftriaxone; combination antimycobacterial therapy consisting of rifampicin, isoniazid, pyrazinamide, and ethambutol; morphine; and iopromide (reporting odds ratio > 1, p < 0.05 for all). Although fatal ADRs are uncommon (<1%) in Korea, they are primarily caused by commonly used medications including antibiotics, analgesics, and contrast media.

Drug-Related Deaths in a Tertiary Hospital: Characteristics of Spontaneously Reported Cases and Comparison to Cases Detected from a Retrospective Study

Drug-related deaths (DRDs) are a common cause of hospital death. Pharmacovigilance, either as spontaneous reporting or active surveillance, plays a key role in the detection and reporting of suspected adverse drug reactions (ADRs). We conducted a retrospective analysis of all DRDs spontaneously reported to a pharmacovigilance program of a tertiary hospital, by health care professionals. We compared these results to those of a previous retrospective study conducted in the same hospital from the hospital's mortality registry. From 1460 spontaneous reported ADRs in a 10-year period, 73 (5%) were DRDs. The median age of DRD was 75 years (range 1 month-94) and 60.3% were men. The most frequent DRDs were hemorrhages (41.1%), followed by infections (17.8%). The most frequently involved drugs were anticoagulants and/or antithrombotic (30%), and antineoplastics (26.3%). When comparing both studies, spontaneous reporting detected more type B reactions (p < 0.001) and hospital-acquired DRD (p < 0.001); the number of concomitant drugs was higher (p = 0.0035); and the kind of ADR were different. The combination of several methods is mandatory to detect, assess, understand, and design strategies to prevent ADRs in a hospital setting, to ensure patient safety.

Fatal adverse drug reactions: A worldwide perspective in the World Health Organization pharmacovigilance database

AIMS

Adverse drug reactions (ADRs) are important causes of death. However, the main involved drugs are relatively unknown. The present study was performed to characterise death-related drugs recorded in a large pharmacovigilance database during the last 10 years.

METHODS

A retrospective analysis of VigiBase, the World Health Organization pharmacovigilance database, was performed investigating fatal ADRs registered between 1 January 2010 and 31 December 2019 in male and female patients aged ≥18 years and reported by physicians. Analyses were descriptive investigating age, sex and suspected drugs. Differences in reporting according to sex, age and continents were investigated using disproportionality analysis with calculation of reporting odds ratio and its 95% confidence interval.

RESULTS

Among the 23 millions ADRs recorded in VigiBase, 3 250 967 were included with 43 685 fatal. They were reported mainly in patients older than 75 years. The 3 most frequently involved drug classes were antineoplastic/immunomodulating drugs followed by nervous system and cardiac drugs. The top 3 individual drugs were denosumab, lenalidomide and thalidomide with marked differences according to age, sex, continents and countries. The risk of reporting fatal ADRs was higher in males, in the Americas and in patients ≥65 years.

CONCLUSION

Fatal ADRs registered in a large pharmacovigilance database during the last 10 years correspond to just over 1% of the total number of ADRs. They occurred more in males, after 65 years and with antineoplastic/immunomodulating drugs in general. Our study also highlighted, for the first time, important differences in fatal ADRs between continents and countries.

Analysis of fatal adverse drug events recorded in several Italian emergency departments (the MEREAFaPS study)

Fatal Adverse Events (FADEs) are a major public health problem, and some FADEs could be preventable. The aim of the present study is to describe the frequency, the drugs involved and the preventability in the FADEs collected through the MEREAFaPS Study between 2012 and 2018. All cases including the outcome "death" have been examined. We excluded cases with vaccine-related ADEs, overdose or suicide, and ADEs occurred during the hospitalisation. Two trained assessors evaluated all cases fulfilling the inclusion criteria. ADEs' preventability was evaluated applying the Schumock and Thornton algorithm. During the study period, we observed 429 cases of death, 92 of which were excluded. The remaining 337 cases involved 187 women and 150 men, with a mean age of 79 and of 77 years, respectively. For each report, the suspected drugs and concomitant ones were 1.26 and 4.20, respectively. Anticoagulants and antiplatelet agents account for more than 40% of FADE cases and the most frequent reactions are haemorrhages (37.5%). The 25% of the FADEs were preventable. This study confirms that FADEs are still a relevant clinical occurrence, and are often caused by widely used old drugs associated with adverse events. The death of one in four patients was preventable. Further efforts should be done to improve the appropriateness of the therapy, especially in older patients who are treated with anticoagulants.

Adverse drug reactions in elderly: a five-year review of spontaneous reports to the Portuguese pharmacovigilance system

Background: Adverse drug reactions (ADRs) are responsible for considerable morbidity and mortality in elderly. This study aimed to characterize the ADRs profile in Portuguese elderly patients, thus enhancing ADRs knowledge in this vulnerable population. Methods: All spontaneous ADRs reported to the Portuguese Pharmacovigilance System from 2013 to 2017 were examined. However, considering the aim of this study, ADRs referring to patients aged 65 and over were analyzed in higher detail and compared with those reported in non-elderly adults. Results: Considering the age of 65 years and above, 3692 spontaneous reports of suspected ADRs were analyzed. The suspected ADRs most frequently reported fall within the categories of general disorders and administration site conditions, and skin and subcutaneous tissue complaints. Regarding therapeutic agents, the antineoplastic drugs were the most common involved. Among the 2458 cases of serious ADRs reported, 34.0% led to hospitalization and in 5.8% of them occurred a fatal outcome. The antineoplastic and antithrombotic drugs were the most represented pharmacotherapeutic groups of suspected drugs involved in patient's death (25.0% and 13.6%, respectively). Conclusions: Most of the suspected ADRs were classified as serious. The majority of them were expected, so preventable, highlighting the importance of improving medication use in elderly.

Mortality from adverse drug reaction-related hospitalizations in south-west Ethiopia: A cross-sectional study

WHAT IS KNOWN AND OBJECTIVE

Adverse drug reactions (ADRs) are an important cause of mortality during medical care. To our knowledge, no Ethiopian studies have reported on mortality due to ADRs in patients presenting to hospital from the community setting. The aim of this study was to determine the mortality rate attributable to ADRs in patients presenting to hospital, identify drugs implicated in the ADR-related deaths and identify factors contributing to ADR-related mortality at Jimma University Specialised Hospital (JUSH), south-west Ethiopia METHODS: This cross-sectional study included 1001 patients aged ≥18 years consecutively admitted to medical wards from May 2015 to August 2016. ADR-related mortality was determined through detailed review of medical records, laboratory tests and patient interviews followed by causality assessment by the Naranjo algorithm and expert consensus.

RESULTS

Of 1001 patients, 15, 1.5% (95% confidence interval [CI]: 0.80%-2.30%) died with an ADR. The primary suspected causes of death were drug-induced hepatotoxicity (7, 43.8%) followed by acute kidney injury (4, 25.0%). Isoniazid (6, 33.3%), pyrazinamide (3, 16.7%), efavirenz (2, 11.1%) and tenofovir (2, 11.1%) were commonly implicated drugs. The majority of ADRs (14, 93.8%) were preventable. Unadjusted bivariate comparisons suggested patients who died with ADRs were more likely to have pre-existing liver disease (40.0% vs 7.0%; 95% confidence interval [CI]: 8.1%-57.8%), a history of ADRs (40% vs 1.4%; 95% CI: 13.8%-63.4%), a lower mean (±SD) body mass index (BMI, 17.6 ± 2.1 vs 20.0 ± 2.9 kg/m² ; 95% CI = 0.9-3.9), exposure to antitubercular (46.7% vs 18.9%; 95% CI: 2.3%-53.1%) and antiretroviral (40.0% vs 7.7%; 95% CI: 7.5%-57.2%) therapies, and a higher mean number of medications (7.1 ± 3.3 vs 3.8 ± 2.1; 95% CI: 2.2-4.4) and Charlson Comorbidity Index (3.9 ± 2.9 vs 1.6 ± 1.8; 95% CI: 1.4-3.2) than surviving patients without ADRs.

WHAT IS NEW AND CONCLUSION

Fatal ADRs were common in patients presenting to hospital. The drugs implicated were mostly antitubercular and antiretroviral therapies, reflecting the high burden of HIV and tuberculosis in the study population. ADR-related deaths were significantly associated with poor nutritional status. The majority of ADR-related deaths were preventable, highlighting the need to develop a multidisciplinary approach to closely monitor patients who are prescribed antitubercular and antiretroviral therapies, particularly in patients with hepatic disease, a history of ADRs, who are malnourished and who are exposed to multiple medications.

Improving drug safety: From adverse drug reaction knowledge discovery to clinical implementation

Adverse drug reactions (ADRs) are a major public health concern, causing over 100,000 fatalities in the United States every year with an annual cost of $136 billion. Early detection and accurate prediction of ADRs is thus vital for drug development and patient safety. Multiple scientific disciplines, namely pharmacology, pharmacovigilance, and pharmacoinformatics, have been addressing the ADR problem from different perspectives. With the same goal of improving drug safety, this article summarizes and links the research efforts in the multiple disciplines into a single framework from comprehensive understanding of the interactions between drugs and biological system and the identification of genetic and phenotypic predispositions of patients susceptible to higher ADR risks and finally to the current state of implementation of medication-related decision support systems. We start by describing available computational resources for building drug-target interaction networks with biological annotations, which provides a fundamental knowledge for ADR prediction. Databases are classified by functions to help users in selection. Post-marketing surveillance is then introduced where data-driven approach can not only enhance the prediction accuracy of ADRs but also enables the discovery of genetic and phenotypic risk factors of ADRs. Understanding genetic risk factors for ADR requires well organized patient genetics information and analysis by pharmacogenomic approaches. Finally, current state of clinical decision support systems is presented and described how clinicians can be assisted with the integrated knowledgebase to minimize the risk of ADR. This review ends with a discussion of existing challenges in each of disciplines with potential solutions and future directions.

The Incidence, Classification, and Management of Acute Adverse Reactions to the Low-Osmolar Iodinated Contrast Media Isovue and Ultravist in Contrast-Enhanced Computed Tomography Scanning

Some epidemiologic surveillance studies have recorded adverse drug reactions to radiocontrast agents. We aimed to investigate the incidence and management of acute adverse reactions (AARs) to Ultravist-370 and Isovue-370 in patients who underwent contrast-enhanced computed tomography (CT) scanning.Data from 137,473 patients were analyzed. They had undergone enhanced CT scanning with intravenous injection of Ultravist-370 or Isovue-370 during the period of January 1, 2006 to December 31, 2012 in our hospital. We investigated and classified AARs according to the American College of Radiology and the Chinese Society of Radiology (CSR) guidelines for iodinated contrast media. We analyzed risk factors for AARs and compared the AARs induced by Ultravist-370 and Isovue-370.Four hundred and twenty-eight (0.31%) patients experienced AARs, which included 330 (0.24%) patients with mild AARs, 82 (0.06%) patients with moderate AARs, and 16 (0.01%) patients with severe AARs (including 3 cases of cardiac arrest and one case of death). The incidence of AARs was higher with Ultravist-370 than with Isovue-370 (0.38% vs 0.24%, P < 0.001), but only for mild AARs (0.32% vs 0.16%, P < 0.001). Analyses on risk factors indicated that female patients (n = 221, 0.43%, P < 0.001), emergency patients (n = 11, 0.51%, P < 0.001), elderly patients aged 50 to 60 years (n = 135, 0.43%, P < 0.001), and patients who underwent coronary computed tomography angiography (CTA) (n = 55, 0.51%, P < 0.001) had a higher risk of AARs. Cutaneous manifestations (50.52%)-especially rash (59.74%)-were the most frequent mild AARs. Cardiovascular manifestations accounted for most moderate and severe AARs (62.91% and 48.28%, respectively). After proper management, the symptoms and signs of 96.5% of the AARs resolved within 24 hours without sequelae.Ultravist-370 and Isovue-370 are safe for patients undergoing enhanced CT scanning. The incidence of AARs is higher with Ultravist-370 than with Isovue-370, but this difference is limited only to the mild AARs. The incidence of AARs could be affected by multiple factors.

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.

Fatal adverse drug reactions: Experience of adverse drug reactions in a tertiary care teaching hospital of North India - A case series

Medical burden of fatal adverse drug reactions (FADRs) is significant. The epidemiological data on FADR do exist from the western world, but there is scanty from India. We hereby report a case series of FADRs recorded in a 2 years period. Point prevalence of FADRs was 0.223%. Point prevalence of all cause death in the hospital was 1.20%. The drugs causing FADRs were injection bupivacaine, amphotericin B, directly observed treatment short-course Category-1, injection streptokinase, and tablet ferrous sulfate. All these FADR were labeled as possible expect one case as probable. All FADR were labeled as type A. In three out of five the central nervous system was involved, while the hepatic system and multiorgan failure accounted for one case each. Two cases each were acute and subacute, while one was latent in nature. Reporting of FADRs shall go a long way in patient safety.

Genotoxicity of nimesulide in Wistar rats

It is mandatory for all new drugs to be tested for their potential genotoxicity in addition to general toxicity testing. Some old drugs have not been tested adequately for their genotoxic effects because these were in use before the local regulations were enforced. According to the material safety database, the toxicological effect of nimesulide is not yet fully understood. The present study therefore aimed to explore the genotoxic potential of nimesulide in Wistar albino rats. Nimesulide at the dose level of 50 (Gr-50), 100 (Gr-100) and 200 (Gr-200) mg/kg body weight (b.w.) was given orally. Each rat in treated groups (Gr-50 to Gr-200; n = 10) and negative control group (Gr-NC; n = 10) were administered orally (p.o.) with nimesulide and normal saline, respectively, for 14 days. Similarly, rats of positive control (Gr-PC; n = 10) were administered with cyclophosphamide (CPA; 20 mg/kg b.w.) intraperitoneally. CPA served as positive control, whereas normal saline served as as negative control. Approximately 1-2 mL of blood was collected from retro-orbital sinus for comet assay and subsequently rats were sacrificed to aspirate the femoral bone marrow for the micronucleus test. Structural chromosomal aberration, micronucleated polychromatic erythrocytes (MnPCEs), polychromatic erythrocytes (PCEs) and comet tail length were calculated using micronucleus assay and comet assay, respectively, which served as markers of genotoxicity. In the present study, it was observed that a significant increase in (1) different classified structural chromosomal aberrations with increase in nimesulide dose, such as gaps (50 mg/kg), gaps, breaks and pulverizations (100 mg/kg) and gaps, breaks, fragments, rings and pulverizations (200 mg/kg) and (2) % MnPCE and comet tail length was observed in animals treated with CPA (p < 0.001) or 200 mg of nimesulide (p < 0.05), as compared to negative control. In conclusion, nimesulide (200 mg/kg b.w.) produced a potential genotoxicity in rats.

Characterisation of non-warfarin-associated bleeding events reported to the Norwegian spontaneous reporting system

OBJECTIVE

The aim of the study was to analyse non-warfarin-associated bleeding adverse drug events reported to the Norwegian spontaneous reporting system, with characterisation of the bleeding locations, outcome and drug interactions. In addition, concordance in assessments between reporters and evaluators, trend shifts in reporting, and detection of potentially new adverse drug interaction signals were studied.

METHODS

Data on bleeding events reported between 1 January 2003 and 31 December 2005 were retrieved from the Norwegian spontaneous reporting system database.

RESULTS

Of 327 case reports of non-warfarin-associated bleeding events, 270 reports (82.6 %) were characterised as serious and 69 (21.1 %) had a fatal outcome. One hundred and eighty-seven bleeds (57.5 %) were gastrointestinal, 57 (17.4 %) were cerebral, and 81 (24.8 %) were from other bleeding sites. The bleeding sites differed with respect to the patient's age, drug use, diagnoses and outcomes. Of drugs associated with bleeding, nonsteroidal anti-inflammatory drugs (NSAIDs)/COX-2 inhibitors (145 reports) and acetylsalicylic acid (128 reports) were most frequently used. Only fibrinolytics were associated with increased mortality. There was a 67.4 % correlation between reporters and evaluators in assessment of drugs associated with bleeding (P < 0.001), with considerable variation in concordance between drug groups.

CONCLUSION

Non-warfarin-associated bleeding events are associated with substantial mortality. Old age, cerebral bleeds, number of drugs used, and use of fibrinolytics are all independently associated with increased mortality. The recognition of the bleeding risk of commonly used drugs such as acetylsalicylic acid and heparins may be insufficient among prescribers.

The profile of voluntary reported adverse drug reactions at a tertiary care hospital: a fifteen month prospective study

OBJECTIVES

The present study was undertaken to provide the health professionals who were working at a tertiary care hospital, with a simple method to report Adverse Drug Reactions (ADRs) and to monitor, document and to evaluate them according to the set criteria.

METHOD AND MATERIALS

This study was conducted over a period of 15 months from 1st Jan' 2008 to 31st March 2009 at Goa Medical College and Hospital (Goa, India). The evaluation of the data was done for various parameters, which included patient demographics and drug and reaction characteristics. An assessment was also done for the outcome, causality and the severity of the drug reactions.

RESULTS

A total of 265 ADRs were reported. Among the drugs, the ß-lactam antibiotics were implicated the maximum number of times (54, 20.37%), followed by fluoroquinolones (35, 13.20%), antiretrovirals (33, 12.45%) and antiepileptics (31, 11.69%). Females showed more ADRs (142, 54%) than males (123, 46%). The skin was involved in about 57.73% (153) of the ADRs, while the CNS and the vascular system were involved in 8.67% (23) and 8.30% (22) of the ADRs. Most of the ADRs were categorized as "Type II" (203, 77%) against "Type I" (62, 23%) by Rawlins and Thompson's classification. The causality assessment was done by the Naranjo Algorithm and 62.26% (165) were seen to fall in the "probable category" as compared to 29.05% (77) in the "highly probable" one. Out of all the ADRs which were reported, 34.71% (148) were "severe", in accordance with the Modified Hartwig and Siegel's scale.

CONCLUSION

The present work was a humble attempt to set up a well organized ADR reporting system at our government hospital. The systematic tracking and monitoring of ADRs can shed light on their extensiveness and their patterns of occurrence.

Data mining methodologies for pharmacovigilance

Medicines are designed to cure, treat, or prevent diseases; however, there are also risks in taking any medicine - particularly short term or long term adverse drug reactions (ADRs) can cause serious harm to patients. Adverse drug events have been estimated to cause over 700,000 emergency department visits each year in the United States. Thus, for medication safety, ADR monitoring is required for each drug throughout its life cycle, including early stages of drug design, different phases of clinical trials, and postmarketing surveillance. Pharmacovigilance (PhV) is the science that concerns with the detection, assessment, understanding and prevention of ADRs. In the pre-marketing stages of a drug, PhV primarily focuses on predicting potential ADRs using preclinical characteristics of the compounds (e.g., drug targets, chemical structure) or screening data (e.g., bioassay data). In the postmarketing stage, PhV has traditionally involved in mining spontaneous reports submitted to national surveillance systems. The research focus is currently shifting toward the use of data generated from platforms outside the conventional framework such as electronic medical records (EMRs), biomedical literature, and patient-reported data in online health forums. The emerging trend of PhV is to link preclinical data from the experimental platform with human safety information observed in the postmarketing phase. This article provides a general overview of the current computational methodologies applied for PhV at different stages of drug development and concludes with future directions and challenges.

Adverse events induced by ceftriaxone: a 10-year review of reported cases to Iranian Pharmacovigilance Centre

WHAT IS KNOWN AND OBJECTIVES

Ceftriaxone, a third-generation cephalosporin antibiotic, is used for a vast variety of infectious diseases. Different types of adverse reactions are reported to be induced by ceftriaxone; however, there is limited published information on spontaneous adverse reactions collected by a national pharmacovigilance centre. This study was conducted to evaluate ceftriaxone-induced adverse drug events, registered in the Iranian pharmacovigilance database during a 10-year period, and to identify preventive measures for reducing ceftriaxone-induced adverse events.

METHOD

All adverse events registered in the Iranian pharmacovigilance database from 1998 through 2009 were screened for ceftriaxone-related adverse events. The extracted data were categorized based on patients' demographics and previous history of allergic reactions to antibiotics. Assessment of system-organ classes, seriousness and causality of reactions was performed according to World Health Organization scale. The preventability was analysed based on Schumock questionnaire.

RESULTS AND DISCUSSION

Ceftriaxone was responsible for the highest number of deaths in our database (49 cases). Of 20,877 reports, 1205 (5·8%) were related to ceftriaxone; 357 reports (30%) are categorized as serious including cardiac arrest, anaphylactic and anaphylactoid reactions. The high number of serious cases makes it necessary to develop preventive measures for reducing those adverse events. Unlabelled use of the drug (2·9%) is identified as one of the risk factors for adverse events. Evaluation of the 1030 intravenous injections of the drug shows that rapid intravenous injection of ceftriaxone is another risk factor. One hundred and sixteen patients (9·6%) had a previous history of allergic reaction to ceftriaxone, penicillin or both. We recommend an alternative antibiotic, if possible, in the case of a positive history of allergic reaction to cephalosporins, penicillins and/or other beta-lactam antibiotics.

WHAT IS NEW AND CONCLUSION

Severe and life-threatening adverse reactions induced by ceftriaxone are of great concern. Rapid intravenous injection, unlabelled use and previous patient history of allergic reactions to cephalosporins or penicillins are risk factors that should be guarded against.

Warfarin-associated bleeding events and concomitant use of potentially interacting medicines reported to the Norwegian spontaneous reporting system

AIMS

To study warfarin associated bleeding events reported to the Norwegian spontaneous reporting system and evaluate the differences in assessment of potentially interacting medicines between reporters and evaluators.

METHODS

Data on bleeding events on warfarin were retrieved from the Norwegian spontaneous reporting system database. Key measurements were time to bleeding, use of concomitant medications and the evaluation done by reporters.

RESULTS

In 289 case reports a total of 1261 medicines (median 4.0 per patient, range 1-17) was used. The evaluators (authors of this article) identified 546 medicines including warfarin (median 2.0 per patient, range 1-7) that could possibly cause bleeding alone or in combination. Reporters assessed 349 medicines (median 1.0 per patient, range 1-4) as suspect. Evaluators identified 156 pharmacokinetic and 101 pharmacodynamic interactions, compared with 19 pharmacokinetic and 56 pharmacodynamic interactions reported as suspected by the reporters. Time to bleeding was stated in 224 reports. Among the early bleeding events, the reports on warfarin without interacting medicines showed the highest INR (international normalized ratio). Heparin was used in 17/21 reported bleeding events during the first week on warfarin. Among the late bleeding events, reports with pharmacokinetic interacting medicines had the highest INR.

CONCLUSIONS

Concomitant use of potentially interacting medicines was involved in the majority of the warfarin-associated bleeding events reported to the Norwegian spontaneous reporting system. Reporters assessed mostly warfarin as the only contributor to bleeding. In particular, pharmacokinetically interacting medicines were not suspected as contributing to bleeding.

Potentially inappropriate medication in elderly hospitalized patients

Balanced and safe prescribing is difficult to achieve in frail older adults with multiple comorbid diseases. This issue is of particular concern, especially in elderly hospitalized patients because hospitalization exposes such individuals to an increased risk of adverse drug reactions (ADRs). The avoidance of medications that are considered to be inappropriate is among the interventions for treatment options in elderly patients. A potentially inappropriate medication (PIM) is a drug in which the risk of an adverse event outweighs its clinical benefit, particularly when there is a safer or more effective alternative therapy for the same condition. Explicit criteria have been developed to identify PIMs and among these, Beers' criteria are the most frequently applied in the literature. However, evidence suggests that such criteria cannot easily be applied to elderly hospitalized people in European countries; approximately 20% of drugs listed in Beers' criteria are rarely prescribed or are not available in Europe, and Beers' listed PIMs are not associated with inhospital mortality, length of hospital stay and/or ADRs in Italian studies. On the contrary, ADRs can contribute to accelerated functional decline in elderly hospitalized patients independently of the use of Beers' listed PIMs. Therefore, we will review the evidence pertaining to the application of Beers' criteria in elderly hospitalized patients, while focusing on Italian studies that have investigated the role of PIMs as potential predictors of negative hospital outcomes. In addition, we will also review the available evidence regarding new European criteria on identifying PIMs, because clinical application in elderly hospitalized Europeans is still under investigation.