Effect of competition bias in safety signal generation: analysis of a research database of spontaneous reports in France

Impact of the vaccination against SARS-CoV-2 campaign on disproportionality indicator from the WHO pharmacovigilance database: A competition bias study from case/non-case analysis

INTRODUCTION

The coronavirus disease 2019 (COVID-19) vaccination campaign has resulted in numerous pharmacovigilance's safety reports which were recorded in the World Health Organization (WHO) pharmacovigilance database (VigiBase) and represent in July 2022 more than 10% of cases recorded. The information component (IC) is a statistical disproportionality measure based on the observed and expected numbers of case reports. A positive value of the lower endpoint of a 95% credibility interval for the information component (IC0.25) suggests a possible causal relationship between the drug and the adverse reaction. This study aimed to evaluate the impact of the wave of COVID-19 vaccines safety declarations on IC0.25 from Vigilyze and thus illustrate with a concrete example the competition bias.

METHODS

We arbitrarily selected 21 adverse drug reactions using Medical Dictionary for Regulatory Activities (MedDRA) preferred terms (PTs), divided in two types: PTs known to be related to COVID-19 vaccines ("expected") and others (type "unexpected"). Data were extracted from VigiLyze. We created two groups: V+ (the full database, including COVID-19 vaccines reports) and V- (the same extraction without COVID-19 vaccine reports). IC0.25 was recomputed for the group V- and we compared the positive signal evolution in the two settings of selection (V+ and V- groups).

RESULTS

The number of positive potential signals was significantly different in the groups V+ and V- for IC0.25. We observed that most of the "unexpected" PTs lost potential signal after the withdrawal of COVID-19 reports. On the contrary, the majority of 'expected' PTs had potential new signals after the withdrawal of COVID-19 reports.

DISCUSSION

This study is one of the first to evaluate the effect of COVID-19 vaccines reporting on Automated Signal Detection of Pharmacovigilance. In this study, we observed that a wave of pharmacovigilance reporting can affect disproportionality estimators such as IC0.25 and then have an impact on automated signal detection; some signals disappear (almost with all PTs related to COVID-19 vaccines) and others appear (mostly with PTs not related to COVID-19 vaccines), illustrating the competition bias.

CONCLUSION

We show that a health crisis involving a change in drug use can affect adverse drug reactions reporting and pharmacovigilance databases, leading to competition bias and a change in the disproportionality analyses. For health professionals who use quantitative disproportionality analysis, it is important not only to use the crude values of indicators but also the kind of PTs and the evolution of the signal over time (take into account major events such as crises).

Cardiovascular Adverse Drug Reactions of Anti-Calcitonin Gene-Related Peptide Monoclonal Antibodies for Migraine Prevention: An Analysis from the European Spontaneous Adverse Event Reporting System

INTRODUCTION

Anti-calcitonin gene-related peptide monoclonal antibodies (anti-CGRP-mAbs) have recently been approved for the prevention of migraine, and their safety profile is not fully characterized.

OBJECTIVE

The aim of this study was to evaluate the adverse drug reactions (ADRs) of anti-CGRP-mAbs through the analysis of individual case safety reports (ICSRs) collected in the EudraVigilance (EV) database, with a specific focus on cardiovascular (CV) ADRs.

METHODS

Data on ICSRs recorded between July 2018 and December 2022 in the EV database, involving one of the anti-CGRP-mAbs for migraine prevention-erenumab (ERE), galcanezumab (GMB), fremanezumab (FMB), and eptinezumab (EPT)-were included in the analysis. All ICSRs reporting at least one CV ADR, as identified within the MedDRA® System Organ Classes (SOCs) "cardiac disorders" or "vascular disorders," were selected for the analysis. The frequency of disproportionate reporting was expressed as the reporting odds ratio (ROR) with its 95% confidence interval (CI), to evaluate the frequency of reporting of CV ADRs for each anti-CGRP-mAb compared with all other monoclonal antibodies (mAbs). A case-by-case analysis was conducted paying particular attention to serious CV ADR reports, focusing on the type of seriousness, age group, sex, and concomitant drugs.

RESULTS

A total of 9441 ICSRs were recorded in the EV database from 2018 to 2022, of which more than half were related to ERE (58.9%), followed by GMB (21.4%), FMB (19.0%), and EPT (0.7%). CV ICSRs accounted for 1205 cases (12.8%), with a total of 1599 CV ADRs. The CV ICSRs were mainly related to female patients (82.6%) aged 18-64 years (73.4%). Of the reported CV ADRs, 67.5% were considered serious. Among the total number of ICSRs related to each anti-CGRP-mAb, those associated with FMB had a higher percentage of CV ADRs (n = 253; 14.1%), followed by ERE (n = 707; 12.7%), EPT (n = 8; 12.7%), and GMB (n = 237; 11.7%). A higher frequency of reporting hypertension was shown for ERE (ROR = 1.45; 95% CI = 1.14-1.85). Pallor was mainly observed with FMB (5.00; 1.68-14.89), as well as deep vein thrombosis (3.86; 1.57-9.51), hot flush (2.16; 1.43-3.25), and palpitations (1.48; 1.05-2.08). Atrial fibrillation (2.36; 1.02-5.46) and myocardial infarction (2.21; 1.37-3.58) were mostly reported for GMB.

CONCLUSION

The analysis of anti-CGRP-related CV ADRs was consistent with the information reported in the literature. However, hypertension with ERE, atrial fibrillation and myocardial infarction with GMB, as well as pallor, deep vein thrombosis, hot flush, and palpitations with FMB were not reported in the Summary of Product Characteristics (SmPCs). Considering this, more post-marketing analyses are needed to improve knowledge on the CV safety profiles of anti-CGRP-mAbs, especially for the last approved medication, EPT.

Drug-induced immune hemolytic anemia: detection of new signals and risk assessment in a nationwide cohort study

ABSTRACT

More than 130 drugs have been suspected to induce immune hemolytic anemia. Comparative studies measuring the risk of drug-induced immune hemolytic anemia (DIIHA) are lacking. We aimed (1) to detect new signals of DIIHA, excluding vaccines, and (2) to assess the association between all suspected drugs and the occurrence of immune hemolytic anemia in a nationwide comparative study. The new signals were identified using a disproportionality study (case/noncase design) in the World Pharmacovigilance Database, Vigibase, among the cases of adverse drug reactions reported up to February 2020 (>20 million). We then conducted a comparative study in the French National health database that links sociodemographic, out-of-hospital, and hospital data for the entire population (67 million individuals). Associations between exposure to drugs (those already reported as DIIHA, plus new signals identified in Vigibase) and incident cases of immune hemolytic anemia (D59.0 and D59.1 diagnosis codes of the International Classification of Diseases, version 10) from 2012 to 2018 were assessed with case-control and case-crossover designs. In Vigibase, 3371 cases of DIIHA were recorded. Fifty-nine new signals were identified resulting in a final list of 112 drugs marketed in France and measurable in the nationwide cohort (n = 4746 patients with incident immune hemolytic anemia included in the case-control analysis matched with 22 447 controls from the general population). We identified an association between immune hemolytic anemia occurrence and some antibiotics, antifungal drugs, ibuprofen, acetaminophen, furosemide, azathioprine, and iomeprol.

Impact of the COVID-19 pandemic on the spontaneous reporting and signal detection of adverse drug events

External factors severely affecting in a short period of time the spontaneous reporting of adverse events (AEs) can significantly impact drug safety signal detection. Coronavirus disease 2019 (COVID-19) represented an enormous challenge for health systems, with over 767 million cases and massive vaccination campaigns involving over 70% of the worldwide population. This study investigates the potential masking effect on certain AEs caused by the substantial increase in reports solely related to COVID-19 vaccines within various spontaneous reporting systems (SRSs). Three SRSs were used to monitor AEs reporting before and during the pandemic, namely, the World Health Organisation (WHO) global individual case safety reports database (VigiBase®), the United States Food and Drug Administration Adverse Event Reporting System (FAERS) and the Japanese Adverse Drug Event Report database (JADER). Findings revealed a sudden over-reporting of 35 AEs (≥ 200%) during the pandemic, with an increment of the RRF value in 2021 of at least double the RRF reported in 2020. This translates into a substantial reduction in signals of disproportionate reporting (SDR) due to the massive inclusion of COVID-19 vaccine reports. To mitigate the masking effect of COVID-19 vaccines in post-marketing SRS analyses, we recommend utilizing COVID-19-corrected versions for a more accurate assessment.

An Exploratory Study of the Impact of COVID-19 Vaccine Spontaneous Reporting on Masking Signal Detection in EudraVigilance

INTRODUCTION

During the signal detection process, statistical methods are used to identify drug-event combinations (DECs) which are disproportionately reported when compared with other drugs and events in the entire database. We hypothesise that the high volume of COVID-19 vaccine adverse drug reaction (ADR) reports transmitted to EudraVigilance may have affected the performance of disproportionality statistics used in routine signal detection, potentially resulting in signals either being masked, or false associations being flagged as potential signals.

OBJECTIVE

Our aim was to study the impact of COVID-19 vaccine spontaneous reporting on statistical signal detection in EudraVigilance.

METHODS

We recalculated the reporting odds ratio (ROR) for signals that were previously discussed at the level of the Pharmacovigilance Risk Assessment Committee, or signals that were retrieved from EudraVigilance, by omitting COVID-19 vaccine reports from the standard ROR calculation and then comparing the lower confidence interval (LCI) of the recalculated ROR to the LCI of the actual ROR in EudraVigilance.

RESULTS

In total, 52 signals for 38 active substances were reviewed. For 35 signals, the LCI of the recalculated ROR value was lower than the LCI of the actual ROR (suggesting that COVID-19 vaccine ADR reporting had a positive effect on the strength of the signal) while for 15 signals the LCI of the recalculated ROR value was higher than the LCI of the actual ROR (suggesting that COVID-19 vaccine ADR reporting had an attenuating effect on the strength of the signal). For two signals, no change in the ROR was observed. In our analysis, six significant results were found. Five DECs were found to be masked: bleomycin and immune thrombocytopenia (actual ROR LCI = 0.94, recalculated ROR LCI = 1.02), vortioxetine and heavy menstrual bleeding (actual ROR LCI = 0.3, recalculated ROR LCI = 1.06), caplacizumab and heavy menstrual bleeding (actual ROR LCI = 0.98, recalculated ROR LCI = 3.47), ziprasidone and amenorrhoea (actual ROR LCI = 0.84, recalculated ROR LCI = 1.67), and azacitidine and pericarditis (actual ROR LCI = 0.81, recalculated ROR LCI = 2.01). For the DEC of adalimumab and immune reconstitution inflammatory syndrome, the LCI of the actual ROR value was 1.14 and removing COVID-19 vaccine reporting resulted in an LCI of the recalculated ROR value of 0.94 (below threshold).

CONCLUSIONS

We demonstrated five cases of masking and one case of false-positive association due to the influence of COVID-19 vaccine spontaneous reporting on the ROR. This suggests that the high number of adverse drug reaction reports for COVID-19 vaccines in EudraVigilance has the potential to affect routine statistical signal detection activities. The impact of COVID-19 vaccine ADR reports on current signal detection practices requires further evaluation and solutions to tackle masking issues in EudraVigilance may need to be developed.

Neurotoxicity induced by taxane-derived drugs: analysis of the FAERS database 2017-2021

OBJECTIVES

Taxane-related neurotoxicity is a frequent clinical problem but lacks postmarketing data regarding neurological disorders. This study aimed to evaluate the potential association between neurological adverse events and several taxanederived drugs via the Food and Drug Administration Adverse Event Reporting System (FAERS).

METHODS

Disproportionality analysis was applied to data mining of the suspected cases of neurological disorders after using different taxanes based on the FAERS data from January 2017 and December 2021. We also investigated the times to onset, fatality, and hospitalization proportions of taxanerelated neurotoxicity.

RESULTS

In total, 3,940 cases were screened out, which were more prevalent in elderly patients and females. Peripheral neuropathy was a common adverse event among all taxanes with relatively strong association. Generally, the median time to neurological adverse effect onset was 27 days (interquartile range, 11.0 ~ 78.0 days) following taxane regimens, and the majority of cases were detected within the first 30 days. Among cases of neurological adverse events treated with taxane, the fatality and hospitalization proportions were 6.13% and 28.63%, respectively.

CONCLUSION

By analyzing the FAERS data, we provided a detailed profile of neurotoxicity and different taxanes in detail in terms of clinical characteristics, time to onset, and patient outcomes.

Examination of Risk Factors and Expression Patterns of Atypical Femoral Fractures Using the Japanese Adverse Drug Event Report Database: A Retrospective Pharmacovigilance Study

Atypical femoral fracture (AFF) is a rare complication related to the use of bisphosphonates (BPs). Herein, we analyzed the risk factors and onset patterns of AFF using the Japanese Adverse Drug Event Report database and reported the findings. First, the independent risk factors for AFF were gender (female), high body mass index, and medical history of osteoporosis, arthritis, and systemic lupus erythematosus (SLE). Drug-related risk factors for AFF included BPs (i.e., alendronic acid, ibandronic acid, etidronic acid, zoledronic acid, minodronic acid, risedronic acid), denosumab, prednisolone, lansoprazole, rabeprazole, exemestane, letrozole, eldecalcitol, and menatetrenone. Therefore, it appears that AFF is influenced by a combination of patient backgrounds and drugs, and that the risk of developing AFF is particularly high in patients with fragile bones (e.g., osteoporosis, arthritis, and SLE). Second, in the analysis of AFF onset patterns, the onset of AFF from BPs and denosumab took a long time (>1 year) to develop. Analysis using a Weibull distribution showed wear-out failure-type AFF onset for BPs and denosumab, and both osteoporosis and cancer patients with long-term administration of these drugs showed a tendency to have an increased risk of onset. AFF developed earlier in osteoporosis patients with long-term administration of BPs and denosumab than in cancer patients.

Adverse event profiles of microscopic colitis in the Japanese Adverse Drug Event Report (JADER) database

Microscopic colitis (MC) is a chronic inflammatory bowel disease that is characterized by nonbloody watery diarrhea. The epidemiology in Japan differs from that in Europe and the United States, but little information is available from epidemiological surveys of MC in Japan. This study aimed to provide a new hypothesis regarding the factors associated with MC by using the Japanese Adverse Drug Event Report (JADER) database. "Colitis microscopic" (preferred term code: 10056979) cases entered into the JADER database between 2004 and 2021 were analyzed. Of the 246,997 cases in the JADER database, 161 cases were observed to be associated with MC. A Weibull analysis revealed that the median onset duration of MC (interquartile range) was 72.5 (36.0‒125.5) days in lansoprazole users and 116.0 (60.3‒1089.0) days in aspirin users. A multiple logistic regression analysis revealed that MC was significantly associated with the female sex, as well as ages ≥ 60 years and drugs including lansoprazole, aspirin, and nicorandil. A subset analysis revealed that MC was positively associated with obesity in female cases. Our study cannot demonstrate a causal inference between MC and each drug; however, the findings suggest that MC was associated with nicorandil as well as with lansoprazole and aspirin.

Nuclear Receptor and Stress Response Pathways Associated with Antineoplastic Agent-Induced Diarrhea

In severe cases, antineoplastic agent-induced diarrhea may be life-threatening; therefore, it is necessary to determine the mechanism of toxicity and identify the optimal management. The mechanism of antineoplastic agent-induced diarrhea is still unclear but is often considered to be multifactorial. The aim of this study was to determine the molecular initiating event (MIE), which is the initial interaction between molecules and biomolecules or biosystems, and to evaluate the MIE specific to antineoplastic agents that induce diarrhea. We detected diarrhea-inducing drug signals based on adjusted odds ratios using the Food and Drug Administration Adverse Event Reporting System. We then used the quantitative structure-activity relationship platform of Toxicity Predictor to identify potential MIEs that are specific to diarrhea-inducing antineoplastic agents. We found that progesterone receptor antagonists were potential MIEs associated with diarrhea. The findings of this study may help improve the prediction and management of antineoplastic agent-induced diarrhea.

Impulse control disorders associated with dopaminergic drugs: A disproportionality analysis using vigibase

BACKGROUND

Dopamine receptor agonist drugs, which are used, for example, to treat Parkinson's disease (PD), increase the risk for impulse control disorders (ICDs), potentially resulting in devastating psychosocial consequences. It is unknown whether other drugs with dopaminergic properties also increase the risk for ICDs. This study assesses the disproportionality of reporting ICDs between drugs with dopaminergic properties and selected non-dopaminergic drugs.

METHODS

A case/non-case disproportionality analysis was performed, using data from VigiBase (1968-2020). Reports on ICDs as suspected adverse drug reactions (ADRs) were cases (n=852), and those with ADRs other than ICDs were non-cases (n=281,720). Relative reporting frequencies were expressed as adjusted reporting odds ratios (aRORs). Within the dopamine receptor agonists, the relationship between reporting odds ratios and dopamine receptor occupancy was explored.

RESULTS

A high disproportionality was found for reporting ICDs for all dopaminergic drugs (aROR 20.4 [95% CI 17.4-24.1]) compared to non-dopaminergic drugs. In pharmacotherapeutic subgroups, a high disproportionality was found for primary dopaminergic agents used in PD (aROR 52.1 [95% CI 44.1-61.5]), and to a lesser extent for ADHD psychostimulants and antidepressants (aROR 5.8 [95% 4.1-8.3] and aROR 3.9 [95% CI 2.9-5.6], respectively). There was no difference in reporting by consumers and healthcare professionals. The highest disproportionality was found for the dopamine receptor agonists pramipexole and ropinirole.

CONCLUSIONS

A signal of disproportion in ICD occurrence was found among all investigated drugs with dopaminergic properties, highlighting the importance of counselling and monitoring for ICDs when prescribing dopaminergic drugs.

New adaptive lasso approaches for variable selection in automated pharmacovigilance signal detection

Background

Adverse effects of drugs are often identified after market introduction. Post-marketing pharmacovigilance aims to detect them as early as possible and relies on spontaneous reporting systems collecting suspicious cases. Signal detection tools have been developed to mine these large databases and counts of reports are analysed with disproportionality methods. To address disproportionality method biases, recent methods apply to individual observations taking into account all exposures for the same patient. In particular, the logistic lasso provides an efficient variable selection framework, yet the choice of the regularization parameter is a challenging issue and the lasso variable selection may give inconsistent results.

Methods

We propose a new signal detection methodology based on the adaptive lasso. We derived two new adaptive weights from (i) a lasso regression using the Bayesian Information Criterion (BIC), and (ii) the class-imbalanced subsampling lasso (CISL), an extension of stability selection. The BIC is used in the adaptive lasso stage for variable selection. We performed an extensive simulation study and an application to real data, where we compared our methods to the existing adaptive lasso, and recent detection approaches based on lasso regression or propensity scores in high dimension. For both studies, we evaluate the methods in terms of false discoveries and sensitivity.

Results

In the simulations and the application, both proposed adaptive weights show equivalent or better performances than the other competitors, with an advantage for the CISL-based adaptive weights. CISL and lasso regression using BIC are solid alternatives.

Conclusion

Our proposed adaptive lasso is an appealing methodology for signal detection in pharmacovigilance. Although we cannot rely on test theory, our approaches show a low and stable False Discovery Rate in all simulation settings. All methods evaluated in this work are implemented in the adapt4pv R package.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-021-01450-3).

Associations between osteoporosis and drug exposure: A post-marketing study of the World Health Organization pharmacovigilance database (VigiBase®)

BACKGROUND

Bone remodeling is a complex process, and many conditions (including drug exposure) lead to osteoporosis. Here, we sought to detect new disproportionality signals for drugs associated with osteoporosis.

METHODS

We performed a disproportionality analysis of the World Health Organization's VigiBase® pharmacovigilance database through April 12, 2020. The frequency of reports on osteoporosis for all identified drug classes was compared with that for all other drugs and quoted as the reporting odds ratio (ROR) [95% confidence interval (CI)].

RESULTS

Of the 7,594,968 cases spontaneously recorded to VigiBase®, 4758 concerned osteoporosis. New disproportionality signals with a pharmacologically plausible mechanism were found for drugs used in neurology (levodopa (ROR [95%CI]: 10.18 [4.33-25.10]), selective serotonin agonists (4.22 [2.34-7.00]) and memantine (4.10 [1.56-8.93])), hematology (romiplostim (4.93 [1.15-21.10])), pulmonology (macitentan (3.02 [1.84-4.90])), ophthalmology (ranibizumab (3.31 [1.00-10.51])) and rheumatology (tofacitinib (3.65 [3.00-4.40])). The robustness of these new results is supported by the significant RORs for the vast majority of drugs already known to induce osteoporosis and/or increase the fracture risk, namely glucocorticoids, gonadotropin-releasing hormone analogs, anti-aromatases, androgen receptor blockers, thyroid hormones, proton pump inhibitors, thiazolidinediones, vitamin K antagonists, loop diuretics, protease inhibitors, nucleoside and nucleotide reverse transcriptase inhibitors, and enzyme-inducing antiepileptics including barbiturates and derivatives, hydantoin derivatives, carboxamide derivatives and fatty acid derivatives.

CONCLUSION

We established up a comprehensive list of drugs potentially associated with osteoporosis and highlighted those with pharmacologically plausible mechanisms leading to bone fragility. Our results might pave the way for additional exploration of these mechanisms.

Risk of Bleeding Associated with Antidepressant Drugs: The Competitive Impact of Antithrombotics in Quantitative Signal Detection

BACKGROUND

To date, disproportionality analysis has been unable to demonstrate the increased bleeding risk associated with antidepressant drugs, especially selective serotonin reuptake inhibitors.

OBJECTIVE

We hypothesised that a potential signal for an increased bleeding risk may be mitigated by the effects of agents other than antidepressant drugs that are strongly associated with haemorrhages, especially antithrombotics. In addition, we investigated if the use of more specific search terms of the Medical Dictionary for Regulatory Activities facilitates the detection of signals.

METHODS

Pharmacovigilance data from the Uppsala Monitoring Centre were used to calculate substance-specific reporting odds ratios (RORs) for all types of bleeding and gastrointestinal bleeding. Reporting odds ratios were calculated with and without antithrombotic comedication.

RESULTS

Regarding any type of bleeding, no signals were found in association with antidepressant drugs. Concerning upper gastrointestinal bleeding, signals were found related to citalopram (ROR: 1.56 [95% confidence interval 1.11-2.20]) and escitalopram (ROR: 1.52 [95% confidence interval 1.03-2.25]). After removal of reports related to antithrombotics, these signals could no longer be detected, but a new signal related to St. John's Wort associated with haemorrhages was found (ROR: 1.50 [95% confidence interval 1.21-1.86]).

CONCLUSIONS

Antithrombotics seem unlikely to have a major impact on the detection of the bleeding risk of antidepressant drugs. The different categorisation of adverse drug reactions regarding the strength of a causal relationship between a drug and an event in the database may be relevant for this negative finding.

Do cariprazine and brexpiprazole cause impulse control symptoms? A case/non-case study

Aripiprazole has been associated with impulse control symptoms (ICS). Recently, two drugs with similar pharmacological features have become available: cariprazine and brexpiprazole. All of them interact with the D₃ receptor, which plays a role in cerebral circuits involved in reward pathways. The objective of this study was to analyze whether a disproportionate number of cases of ICS are reported for cariprazine or brexpiprazole in EudraVigilance. A case/non-case study was conducted to assess the association between ICS and these antipsychotics, calculating reporting odds ratios (RORs) from their respective approval date to Nov 17, 2020. First, cases involving cariprazine or brexpiprazole were compared with those involving all other drugs. Second, to reduce the risk of confounding by indication, the RORs for cariprazine and brexpiprazole were compared with other antipsychotics. Besides, to evaluate a possible notoriety bias, a sensitivity analysis excluding aripiprazole was performed. Seven cases of ICS were reported for cariprazine and another seven for brexpiprazole. The ROR for cariprazine was 28.3 (95% confidence interval [CI], 13.4-59.8) and 33.4 (15.8-70.1) in the case of brexpiprazole. Nonetheless, this association disappeared for cariprazine when compared with other antipsychotics drugs. However, when excluding aripiprazole from the analysis, a safety signal emerged. Although our study is the first to suggest an association between cariprazine, brexpiprazole and ICS, these results should only be considered as exploratory in the context of safety signal detection. Further, well designed observational analytical studies will be needed to confirm these results.

Comprehensive Analysis of Chemotherapeutic Agents That Induce Infectious Neutropenia

Chemotherapy-induced neutropenia (CIN) has been associated with a risk of infections and chemotherapy dose reductions and delays. The chemotherapy regimen remains one of the primary determinants of the risk of neutropenia, with some regimens being more myelotoxic than others. Although a number of clinical trials have currently highlighted the risk of CIN with each chemotherapy regimen, only a few ones have comprehensively examined the risk associated with all chemotherapeutic agents. Therefore, this study aimed to investigate the risk factors and characteristics of CIN caused by each neoplastic agent using data from the large voluntary reporting Food and Drug Administration Adverse Event Reporting System database. Initially, univariate analysis showed that an age ≥ 65 years, the female sex, and treatment with chemotherapeutic agents were factors that caused CIN. Then, cluster and component analyses showed that cytotoxic agents (i.e., alkylating agents, antimetabolic agents, antineoplastic antibiotics, platinating agents, and plant-derived alkaloids) were associated with infection following neutropenia. This comprehensive analysis comparing CIN risk suggests that elderly or underweight patients treated with cytotoxic drugs require particularly careful monitoring.

The Impact of Serotonin Transporter Binding Affinity on the Risk of Bleeding Related to Antidepressants

PURPOSE/BACKGROUND

The alleged primary mechanism underlying bleeding events associated with antidepressants is inhibition of serotonin uptake in platelets resulting in reduced platelet aggregability and activity, and prolonged bleeding time. There is some evidence that a substance's degree of serotonin reuptake inhibition in terms of its binding affinity to the serotonin transporter (SERT) affects the magnitude of bleeding risk increase.

METHODS/PROCEDURE

To test this hypothesis, we performed data mining in the worldwide largest pharmacovigilance database (VigiBase) and conducted pharmacodynamically informed quantitative signal detection. Reporting odds ratios related to the standardized Medical Dictionary of Regulatory Activities query term "haemorrhages" and 24 antidepressants were calculated, and SERT binding affinities (pKi) were obtained and correlated (Pearson correlation).

FINDINGS/RESULTS

A strong and statistically significant correlation between substance-related reporting odds ratios and SERT binding affinities was found (r = 0.63; 95% confidence interval, 0.30-0.82; P = 0.00097).

IMPLICATIONS/CONCLUSIONS

Our findings strengthen the hypothesis that inhibition of serotonin uptake contributes to the antidepressant-related bleeding risk and suggest an association between the degree of the SERT binding affinity and the bleeding risk. This supports the preferential use of antidepressants with low or no SERT binding affinity in depressed patients at risk of bleeding.

COVID-19 in DMARD-treated patients with inflammatory rheumatic diseases: Insights from an analysis of the World Health Organization pharmacovigilance database

Background

To determine whether the use of disease‐modifying antirheumatic drugs (DMARDs) is linked to the risk of COVID‐19 among patients with inflammatory rheumatic diseases (IRDs).

Methods

We performed a disproportionality analysis of the World Health Organization pharmacovigilance database between January 1, 2020, and June 10, 2020. The frequency of COVID‐19 reports for all DMARD classes identified was compared with that for all other reports for all other drugs and quoted as the reporting odds ratio (ROR) (95% confidence interval [CI]).

Results

Among 980,446 individual case‐safety reports voluntarily recorded in the database, 398 identified COVID‐19 in DMARD‐treated patients with IRDs. There were 177 (44.5%) patients with rheumatoid arthritis (RA), 120 (30.1%) with ankylosing spondylitis (AS), 93 (23.4%) with psoriatic arthritis (PsA), and 8 (2.0%) with juvenile idiopathic arthritis. Most of the cases of COVID‐19 occurred in patients taking anti‐TNF agents (84.2%), resulting in a significant disproportionality signal (ROR [95% CI]: 8.31 [7.48–9.23]) – particularly in patients with RA, AS or PsA. A significant inverse disproportionality was found for the anti‐IL‐6 agent tocilizumab (ROR [95% CI]: 0.12 [0.02–0.88]) and JAK inhibitors (ROR [95% CI]: 0.33 [0.19–0.58]) in patients with RA – suggesting that these two drug classes are safer in the context of RA.

Conclusion

Our results are in line with the literature on a potentially better safety profile for anti‐IL‐6 agents and JAK inhibitors. The WHO pharmacovigilance data suggest that COVID‐19 is significantly more frequent in patients with IRDs treated with TNF inhibitors.

Evaluation of the Expression Profile of Irinotecan-Induced Diarrhea in Patients with Colorectal Cancer

Irinotecan (CPT-11) is widely used for the treatment of unresectable colorectal cancer in combination with fluoropyrimidines, such as 5-fluorouracil and S-1. Diarrhea is one of the adverse effects associated with CPT-11 and frequently reported by patients treated with CPT-11-containing regimens combined with oral fluoropyrimidines. However, the mechanisms involved in this process, as well as whether fluctuations in the frequency and differences in the onset time of diarrhea with each CPT-11-containing regimen are caused by drug interactions remain unclear. Therefore, we examined the incidence of diarrhea caused by each CPT-11-containing regimen in patients with colorectal cancer using data from the large voluntary reporting Japanese Adverse Drug Event Report (JADER) database. Firstly, we searched for suspected drugs related to the occurrence of diarrhea using reported odds ratio and calculated the signal score to assess drug–drug interactions. Subsequently, we conducted a time-to-onset analysis using Weibull distribution. The results showed that the combination of CPT-11 with S-1 increased the frequency of diarrhea due to a pharmacological interaction but delayed its onset. The present results may contribute to the appropriate management of drug-induced adverse effects by healthcare professionals.

A safety signal of somnambulism with the use of antipsychotics and lithium: A pharmacovigilance disproportionality analysis

AIMS

Antipsychotics and lithium are widely used in psychiatry, particularly in schizophrenia and bipolar disorders. Recently, some cases of somnambulism or sleep-related eating disorder (SRED) have been reported in patients treated with these drugs. This study investigated the risk of reporting somnambulism or SRED associated with the use of antipsychotics and lithium.

METHODS

The World Health Organization pharmacovigilance database (VigiBase), comprising >18 million adverse events, was queried. All somnambulism or SRED reports related to antipsychotics or lithium were identified. The association between antipsychotics or lithium and somnambulism or SRED was computed using the proportional reporting ratio (PRR) and information component.

RESULTS

Among the 5784 cases reporting somnambulism or SRED, 508 suspected at least 1 antipsychotic or lithium. Most patients were aged 18-64 years (62.0%), and 37.0% were men. In most cases (77.6%), antipsychotic or lithium were the only drug class involved, and 53.3% of cases suspected quetiapine. Somnambulism was reported in 88.6% of cases and SRED in 18.1%. A significant association was found for second-generation antipsychotics (PRR 3.44, 95% confidence interval 3.13) and lithium (PRR 2.03, [1.22; 3.37]), but not for first-generation antipsychotics (PRR 0.99, [0.68; 1.44]).

CONCLUSIONS

We found a significant signal of somnambulism or SRED related to second-generation antipsychotics and lithium. While case reports mentioned mostly quetiapine and olanzapine, almost all second-generation antipsychotics were associated with somnambulism or SRED.

Adverse drug reaction risks obtained from meta-analyses and pharmacovigilance disproportionality analyses are correlated in most cases

OBJECTIVE

We aimed at testing if a correlation between adverse drug reactions relative risks estimated from meta-analyses and disproportionality analyses calculated from pharmacovigilance spontaneous reporting systems databases exist, and if methodological choices modify this correlation.

STUDY DESIGN

We extracted adverse drug reactions (ADR) odds ratios (ORs) from meta-analyses used as reference and calculated corresponding Reporting Odds Ratios (RORs) from the WHO pharmacovigilance database according to five different designs. We also calculated the relative bias and agreement of ROR compared to ORs.

RESULTS

We selected five meta-analyses which displayed a panel of 13 ADRs. A significant correlation for 7 out of the 13 ADRs studied in the primary analysis was found. The methods for ROR calculation impacted the results but none systematically improved the correlations. Whereas correlation was found between OR and ROR, agreement was poor and relative bias was important.

CONCLUSION

Despite the large variation in disproportionality analyses results due to design specification, this study provides further evidence that relative risks obtained from meta-analyses and from disproportionality analyses correlate in most cases, in particular for objective ADR not associated with the underlying pathology.

Risk of Bleeding Associated With Antidepressants: Impact of Causality Assessment and Competition Bias on Signal Detection

Introduction: Until now, methods of pharmacovigilance as disproportionality analysis were not capable of proving the otherwise well-established increased bleeding risk related to antidepressants (ADs). As bleeding events with ADs often occur in combination with antithrombotics, they might not be considered causative of, but merely "linked" with, the bleeding event. Therefore, we hypothesized that the causality assessment of bleeding events in association with ADs and the competitive impact of antithrombotics are factors contributing to the non-findings of previous pharmacovigilance studies. Methods: We performed a case/non-case study based on data from VigiBase^TM and calculated reporting odds ratios (RORs) for 25 ADs. We used individual case safety reports (ICSRs) that were differently categorized in the database regarding their type of association between drug and event. Furthermore, we investigated the competitive impact of antithrombotics by comparing RORs with and without ICSRs related to antithrombotics. Results: Analysis of ICSRs that were categorized as causally associated resulted in the detection of only two signals (citalopram and escitalopram; upper gastrointestinal bleeding). Analysis of ICSRs irrespective of the type of association resulted in the detection of signals in 8 out of 25 ADs (regarding bleeding, in general, gastrointestinal bleeding and upper gastrointestinal bleeding). Consideration of ICSRs associated with antithrombotics as competitive substances did not have a major impact on signal detection in our analysis. Conclusion: Categorization of the type of association between drug and event affects the results of quantitative signal detection. Causality assessment seems to play a major role in signal detection, probably particularly concerning rare, unknown, or clinically insignificant adverse drug reactions. ADs appear to significantly increase the bleeding risk, even independent of antithrombotic comedication.

Comprehensive Study of the Risk Factors for Medication-Related Osteonecrosis of the Jaw Based on the Japanese Adverse Drug Event Report Database

Medication-related osteonecrosis of the jaw (MRONJ) is associated with many drugs, including bisphosphonates (BPs). BPs are associated with atypical femoral fractures and osteonecrosis of the external auditory canal. Thus, many drugs are reported to cause adverse effects on bone. This study aimed to investigate the effects of drugs and patient backgrounds regarding osteonecrosis-related side effects, including MRONJ. This study used a large voluntary reporting database, namely, the Japanese Adverse Drug Event Report database. First, we searched for risk factors related to MRONJ using volcano plots and logistic regression analysis. Next, we searched for bone-necrosis-related side effects using principal component and cluster analysis. Factors that were significantly associated with MRONJ included eight types of BPs and denosumab, prednisolone, sunitinib, eldecalcitol, raloxifene, letrozole, doxifluridine, exemestane, radium chloride, medroxyprogesterone, female, elderly, and short stature. Furthermore, antiresorptive agents (i.e., BPs and denosumab) tended to induce MRONJ and atypical femoral fractures by affecting osteoclasts. We believe these findings will help medical personnel manage the side effects of many medications.

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

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

Cardiovascular Toxicity of Tyrosine Kinase Inhibitors Used in Chronic Myeloid Leukemia: An Analysis of the FDA Adverse Event Reporting System Database (FAERS)

Tyrosine kinase inhibitors (TKIs), the treatment of choice for chronic myeloid leukemia (CML), can be associated to cardiovascular (CV) adverse events (AEs). A case/non-case study was performed using AE reports registered in the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database to compare the risk of CV event reports related to TKIs indicated in the management of chronic myeloid leukemia (CML). Disproportionality of CV event-related TKIs was computed using the Reporting Odds Ratio (ROR) as a measure of potential risk increase. Nilotinib accounts for more than half of reported cases related to TKIs. Signal of Disproportionate Reporting (SDR) was found for cardiac failure, ischemic heart disease, cardiac arrhythmias, torsade de pointes/QT prolongation, hypertension, and pulmonary hypertension. Dasatinib and bosutinib were related to the highest disproportionality for cardiac failure. Nilotinib was associated with the highest SDR for ischemic heart disease, torsade de pointes/QT prolongation and cardiac arrhythmias. Only ponatinib was related to an SDR for hypertension, while dasatinib and imatinib were related to pulmonary hypertension. In the context of CML, TKIs have different safety profiles related to CV events, among which nilotinib seems particularly related to. These results claim for a revision of its CV safety profile mainly for the risk of torsade de pointes/QT prolongation.

Adverse Drug Reaction Risk Measures: A Comparison of Estimates from Drug Surveillance and Randomised Trials

BACKGROUND

Most drug regulatory agencies and pharmaceutical companies hold databases of spontaneous reports of suspected adverse drug reactions (ADRs). Detection systems for ADR signals have been created by specialists to analyse such reports, based on the concept of disproportionality, in order to support safety decision making. However, these measures are often misinterpreted by non-specialists in pharmacovigilance.

OBJECTIVES

Our aim was to assess agreement between estimates of risk from spontaneous reports of suspected ADRs and estimates of risks of ADRs from randomised controlled trials (RCTs).

METHODS

From 150 drugs randomly selected from the US Food and Drug Administration's Adverse Event Reporting System (FAERS), we identified drugs where FAERS provided reporting odds ratios (RORs) and corresponding systematic reviews from the Cochrane database gave (pooled) odds ratios (ORs) for the same drugs and adverse reactions. We assessed agreement between (ln) RORs and (ln) ORs using the Pearson correlation coefficient and the Bland-Altman agreement method, and performed sensitivity analyses.

RESULTS

We identified 6 drugs and 125 ADRs. Overall, there was a weak correlation (r = 0.20) between RORs (FAERS) and ORs (RCTs). However, we observed a stronger correlation (r = 0.78) between RORs and ORs for one drug (roflumilast) that received market approval relatively recently (2011).

CONCLUSIONS

Spontaneous reporting of suspected ADRs is an important tool for regulatory agencies and pharmaceutical companies in making decisions and detecting drug safety signals. Although there was moderate-to-strong agreement between ADR risk estimates from drug surveillance and RCTs for one drug, this study illustrates the current recommendations not to use disproportionality measures as valid proxies for risk estimates.

Bayesian hierarchical methods in the detection of potentially teratogenic first-trimester medications

PURPOSE

Bayesian hierarchical models (BHMs) have been used to identify adverse drug reactions, allowing information sharing amongst adverse reactions and drugs expected to have similar properties. This study evaluated the use of BHMs in the routine signal detection analyses of potential first-trimester teratogens, where these models have not previously been applied.

METHODS

Data on 15 058 malformed foetuses exposed to first trimester medications (1995-2011) from 13 European congenital anomaly (CA) registries were analysed. The proportion of each CA in women taking a specific medication was compared with the proportion of that CA in all other women in the dataset (55 CAs × 523 medications). BHMs were grouped by either medications or CAs or by both simultaneously, and the results compared with analysing each medication-CA combination separately and adjusting for multiplicity using a double false discovery rate (FDR) procedure. The proportions of "high-risk" medications (medications which have been shown to carry a moderate to high risk of foetal malformations) identified as potential signals were compared, as well as the total number of potential signals requiring follow up (the effective workload).

RESULTS

BHMs identified more high-risk medications than the double FDR method, but the effective workload was larger. A BHM grouping both medications and CAs, for example, identified 23% of high-risk medications compared with 14% by the double FDR; however, there was an increase from 16 to 71 potential signals requiring follow up.

CONCLUSION

For comparable effective workloads, BHMs did not outperform the double FDR, which is comparatively straightforward to implement and is therefore recommended for continued use in teratogenic signal detection analyses.

Parkinsonism associated with gabapentinoid drugs: A pharmacoepidemiologic study

BACKGROUND

Use of gabapentinoids is increasing. Following recent case reports, we investigated a putative risk of parkinsonism with pregabalin or gabapentin.

METHODS

A disproportionality analysis of 5,653,547 individual case safety reports in the World Health Organization individual case safety report database, VigiBase, compared all patients with parkinsonism who were receiving gabapentinoids with other patients. Results are shown as reporting odds ratios and the information component, an indicator of disproportionate Bayesian reporting. Sensitivity analyses included comparisons with drugs used for similar indications (amitriptyline, duloxetine) and exclusion of drugs that induce parkinsonism.

RESULTS

Among 5,653,547 reports, 4925 parkinsonism reports were found with pregabalin and 4881 with gabapentin. Gabapentin and pregabalin were associated with increased reporting odds ratio (2.16 [2.10-2.23], 2.43 [2.36-2.50]). Similar trends were found using information components after excluding drugs that induce parkinsonism and for pregabalin compared with amitriptyline or duloxetine.

CONCLUSIONS

This study found that gabapentinoids (particularly pregabalin) can be associated with parkinsonism. © 2019 International Parkinson and Movement Disorder Society.

Pharmacovigilance - The next chapter

The discovery and quantification of adverse drug reactions has long relied on the careful analysis of spontaneously reported cases. Causality assessment (imputation) was a fundamental feature of individual case report analysis. This was complemented by analysis of aggregated cases, and of disproportionality analyses in spontaneous reports databases. In the absence of more specific information sources, these have resulted in the discovery of many new adverse reactions, altering drug information. It has led to the withdrawal from the market of many drugs, but its use for risk quantification remains fraught with uncertainty. The recent access to population-wide claims or electronic health records databases have confirmed for spontaneous reporting a predominant role in hypothesis generation for serious adverse drug reactions, notably those that result in hospital admission or death. In these cases, the events are identifiable at the population level, and can be quantified precisely using the tools of modern pharmacoepidemiology, to generate specific benefit-risk analyses. Spontaneous reporting remains irreplaceable in signal and alert generation in drug safety, despite its inherent limitations. For signal strengthening and assessment, more systematic and quantitative methods should be sought, such as claims databases for reactions resulting in hospital admissions.

Spontaneous adverse event notifications by patients subsequent to the marketing of a new formulation of Levothyrox® amidst a drug media crisis: atypical profile as compared with other drugs

Since patients may report spontaneously adverse events associated with their medications, such notifications are constantly on the rise. In 2017, an unexpected rise of notifications associated with the marketing of a new formula of Levothyrox, differing from the 30-year-old drug only by minor elements, occurred in France amidst widespread media coverage. Not much, if any, scientific or pharmacological rationale was identified to explain that signal. This led us to focus on the profile and the clinical characteristics of these notifications and compare them to those associated with other drugs. We gathered all the spontaneous drug adverse event notifications associated with either Levothyrox^® or other drugs, that we received from patients in 2017, in the sanitary territory of ~2.3 M people we surveyed. Each notification was assessed by a multidisciplinary team. We compared the number of notifications, the number of symptoms described and their clinical characteristics. A total of 1 544 patient notifications were evaluated: 1 372 cases totaling 7 342 adverse events concerned Levothyrox^® new formula, as compared with 172 cases reporting 528 adverse events for all other drugs. The number of symptoms reported per notification was significantly higher for Levothyrox^® (5.4) than for other drugs (3.1, P < 0.001). Symptoms associated with Levothyrox^® belonged to more System Organ Classes and were often unrelated to the disease or treatment, as compared with those associated with other drugs. The distribution of the cases according to the number of symptoms described was starkly different, the Levothyrox^® distribution being unimodal. Health authorities must address this issue as such large atypical reporting disproportionally affects the European pharmacovigilance database.

Pharmacovigilance of sodium-glucose co-transporter-2 inhibitors: What a clinician should know on disproportionality analysis of spontaneous reporting systems

Sodium-glucose co-transporter-2 inhibitors (SGLT2-Is) have consistently demonstrated a clinically significant reduction of cardiovascular mortality. However, their safety in clinical practice is still incompletely characterized, and post-marketing monitoring is required considering the expected increase in clinical use. Different analyses of international spontaneous reporting systems, known as disproportionality analyses (DAs), have highlighted the occurrence of ketoacidosis, amputations, acute renal failure and skin toxicity. In this viewpoint, we critically appraise these pharmacovigilance data on SGLT2-Is, with the aim of supporting clinicians in proper interpretation of these studies, and discussing their risk-benefit profile. To this aim, we offer a broad perspective on basic technical aspects subtending DAs of spontaneous reporting databases (describing peculiarities of the Food and Drug Administration Adverse Event Reporting System), their common and evolving uses, key pitfalls in presenting study results (in terms of "risk" or "association") and relevant strategies to account for major confounders. This will also facilitate reviewers and editors in proper evaluation of DAs, and prompt pharmacovigilance experts in converging towards a set of minimum requirements in standardization of design, performance and reporting of DAs. A consensus on quality assessment of DAs will finally establish their transferability to clinical practice. It is anticipated that DAs cannot be used per se as a standalone approach to assess a drug-related risk and cannot replace clinical judgment in the individual patient.

False-positive results in pharmacoepidemiology and pharmacovigilance

False-positive constitute an important issue in scientific research. In the domain of drug evaluation, it affects all phases of drug development and assessment, from the very early preclinical studies to the late post-marketing evaluations. The core concern associated with this false-positive is the lack of replicability of the results. Aside from fraud or misconducts, false-positive is often envisioned from the statistical angle, which considers them as a price to pay for type I error in statistical testing, and its inflation in the context of multiple testing. If envisioning this problematic in the context of pharmacoepidemiology and pharmacovigilance however, that both evaluate drugs in an observational settings, information brought by statistical testing and the significance of such should only be considered as additional to the estimates provided and their confidence interval, in a context where differences have to be a clinically meaningful upon everything, and the results appear robust to the biases likely to have affected the studies. In the following article, we consequently illustrate these biases and their consequences in generating false-positive results, through studies and associations between drug use and health outcomes that have been widely disputed.

A mathematical framework to quantify the masking effect associated with the confidence intervals of measures of disproportionality

BACKGROUND

The lower bound of the 95% confidence interval of measures of disproportionality (Lower95CI) is widely used in signal detection. Masking is a statistical issue by which true signals of disproportionate reporting are hidden by the presence of other medicines. The primary objective of our study is to develop and validate a mathematical framework for assessing the masking effect of Lower95CI.

METHODS

We have developed our new algorithm based on the masking ratio (MR) developed for the measures of disproportionality. A MR for the Lower95CI (MRCI) is proposed. A simulation study to validate this algorithm was also conducted.

RESULTS

We have established the existence of a very close mathematical relation between MR and MRCI. For a given drug-event pair, the same product will be responsible for the highest masking effect with the measure of disproportionality and its Lower95CI. The extent of masking is likely to be very similar across the two methods. An important proportion of identical drug-event associations affected by the presence of an important masking effect is revealed by the unmasking exercise, whether the proportional reporting ratio (PRR) or its confidence interval are used.

CONCLUSION

The detection of the masking effect of Lower95CI can be automated. The real benefits of this unmasking in terms of new true-positive signals (rate of true-positive/false-positive) or time gained by the revealing of signals using this method have not been fully assessed. These benefits should be demonstrated in the context of prospective studies.

Analysis of factors associated with hiccups based on the Japanese Adverse Drug Event Report database

Hiccups are occasionally experienced by most individuals. Although hiccups are not life-threatening, they may lead to a decline in quality of life. Previous studies showed that hiccups may occur as an adverse effect of certain medicines during chemotherapy. Furthermore, a male dominance in hiccups has been reported. However, due to the limited number of studies conducted on this phenomenon, debate still surrounds the few factors influencing hiccups. The present study aimed to investigate the influence of medicines and patient characteristics on hiccups using a large-sized adverse drug event report database and, specifically, the Japanese Adverse Drug Event Report (JADER) database. Cases of adverse effects associated with medications were extracted from JADER, and Fisher’s exact test was performed to assess the presence or absence of hiccups for each medication. In a multivariate analysis, we conducted a multiple logistic regression analysis using medication and patient characteristic variables exhibiting significance. We also examined the role of dexamethasone in inducing hiccups during chemotherapy. Medicines associated with hiccups included dexamethasone, levofolinate, fluorouracil, oxaliplatin, carboplatin, and irinotecan. Patient characteristics associated with hiccups included a male gender and greater height. The combination of anti-cancer agent and dexamethasone use was noted in more than 95% of patients in the dexamethasone-use group. Hiccups also occurred in patients in the anti-cancer agent-use group who did not use dexamethasone. Most of the medications that induce hiccups are used in chemotherapy. The results of the present study suggest that it is possible to predict a high risk of hiccups using patient characteristics. We confirmed that dexamethasone was the drug that has the strongest influence on the induction of hiccups. However, the influence of anti-cancer agents on the induction of hiccups cannot be denied. We consider the results of the present study to be helpful for the prevention and treatment of hiccups.

A Method for the Minimization of Competition Bias in Signal Detection from Spontaneous Reporting Databases

INTRODUCTION

The two methods for minimizing competition bias in signal of disproportionate reporting (SDR) detection--masking factor (MF) and masking ratio (MR)--have focused on the strength of disproportionality for identifying competitors and have been tested using competitors at the drug level.

OBJECTIVES

The aim of this study was to develop a method that relies on identifying competitors by considering the proportion of reports of adverse events (AEs) that mention the drug class at an adequate level of drug grouping to increase sensitivity (Se) for SDR unmasking, and its comparison with MF and MR.

METHODS

Reports in the French spontaneous reporting database between 2000 and 2005 were selected. Five AEs were considered: myocardial infarction, pancreatitis, aplastic anemia, convulsions, and gastrointestinal bleeding; related reports were retrieved using standardized Medical Dictionary for Regulatory Activities (MedDRA(®)) queries. Potential competitors of AEs were identified using the developed method, i.e. Competition Index (ComIn), as well as MF and MR. All three methods were tested according to Anatomical Therapeutic Chemical (ATC) classification levels 2-5. For each AE, SDR detection was performed, first in the complete database, and second after removing reports mentioning competitors; SDRs only detected after the removal were unmasked. All unmasked SDRs were validated using the Summary of Product Characteristics, and constituted the reference dataset used for computing the performance for SDR unmasking (area under the curve [AUC], Se).

RESULTS

Performance of the ComIn was highest when considering competitors at ATC level 3 (AUC: 62 %; Se: 52 %); similar results were obtained with MF and MR.

CONCLUSION

The ComIn could greatly minimize the competition bias in SDR detection. Further study using a larger dataset is needed.

Good Signal Detection Practices: Evidence from IMI PROTECT

Over a period of 5 years, the Innovative Medicines Initiative PROTECT (Pharmacoepidemiological Research on Outcomes of Therapeutics by a European ConsorTium) project has addressed key research questions relevant to the science of safety signal detection. The results of studies conducted into quantitative signal detection in spontaneous reporting, clinical trial and electronic health records databases are summarised and 39 recommendations have been formulated, many based on comparative analyses across a range of databases (e.g. regulatory, pharmaceutical company). The recommendations point to pragmatic steps that those working in the pharmacovigilance community can take to improve signal detection practices, whether in a national or international agency or in a pharmaceutical company setting. PROTECT has also pointed to areas of potentially fruitful future research and some areas where further effort is likely to yield less.

Role of serotonin 5-HT2C and histamine H1 receptors in antipsychotic-induced diabetes: A pharmacoepidemiological-pharmacodynamic study in VigiBase

Pharmacodynamic mechanisms of diabetes induced by antipsychotic drugs remain unclear, while numerous receptors have been suspected to be involved in the genesis of this Adverse Drug Reaction (ADR). We investigated potential relationships between antipsychotics׳ receptor occupancy (serotonin 5-HT1A, 5-HT2A, 5-HT2C, histamine H1, muscarinic M3, adrenergic α1, α2 or dopaminergic D2 D3 occupancies) and reports of diabetes using VigiBase(®), the World Health Organization (WHO) global Individual Case Safety Report (ICSR) database. All ADR reports from 15 first and second generation antipsychotic drugs recorded in VigiBase(®) were extracted. Logistic regression models, completed by disproportionality analysis, were used to determine the associations between antipsychotics׳ receptor occupancy and ICSRs of diabetes on VigiBase(®). During the study period, 94,460 ICSRs involved at least one of the 15 antipsychotics of interest. Diabetes was reported in 1799 (1.9%) patients. Clozapine was the most frequently suspected drug (n=953; 53.0%). A significant and positive association was found between histamine H1, muscarinic M3 and serotonin 5-HT2C, 5-HT2A receptor occupancies and reports of diabetes. A multivariable stepwise regression model showed that only serotonin 5-HT2c (AOR=2.13, CI 95% 1.72-2.64) and histamine H1 (AOR=1.91, CI 95% 1.38-2.64) predicted the risk for diabetes mellitus (p<0.001). Using an original pharmacoepidemiology-pharmacodynamic (PE-PD) approach, our study supports that antipsychotic drugs blocking simultaneously histamine H1 and serotonin 5-HT2C receptors are more frequently associated with diabetes reports in VigiBase(®) than other antipsychotics. These findings should encourage investigation of histamine H1 and serotonin 5-HT2C properties for predicting the risk of glycemic effects in candidate antipsychotics.

Liver injury with novel oral anticoagulants: assessing post-marketing reports in the US Food and Drug Administration adverse event reporting system

AIM

We assessed the hepatic safety of novel oral anticoagulants (NOACs) analyzing the publicly available US-FDA adverse event reporting system (FAERS).

METHODS

We extracted reports of drug-induced liver injury (DILI) associated with NOACs, including acute liver failure (ALF) events. Based on US marketing authorizations, we performed disproportionality analyses, calculating reporting odds ratios (RORs) with 95% confidence interval (CI), also to test for event- and drug-related competition bias, and case-by-case evaluation for concomitant medications.

RESULTS

DILI reports represented 3.7% (n = 146) and 1.7% (n = 222) of all reports for rivaroxaban and dabigatran, respectively. No statistically significant association was found for dabigatran, in primary and secondary analyses. Disproportionality signals emerged for rivaroxaban in primary analysis (ALF: n = 25, ROR = 2.08, 95% CI 1.34, 3.08). In a large proportion of DILI reports concomitant hepatotoxic and/or interacting drugs were recorded: 42% and 37% (rivaroxaban and dabigatran, respectively), especially statins, paracetamol and amiodarone. Among ALF reports, fatal outcome occurred in 49% of cases (44% and 51%, rivaroxaban and dabigatran, respectively), whereas rapid onset of the event (<1 week) was detected in 46% of patients (47% and 44%, respectively).

CONCLUSIONS

The disproportionality signal for rivaroxaban calls for further comparative population-based studies to characterize and quantify the actual DILI risk of NOACs, taking into account drug- and patient-related risk factors. As DILI is unpredictable, our findings strengthen the role of (a) timely pharmacovigilance to detect post-marketing signals of DILI through FAERS and other data sources, (b) clinicians to assess early, on a case-by-case basis, the potential responsibility of NOACs when they diagnose a liver injury.

Reducing the noise in signal detection of adverse drug reactions by standardizing the background: a pilot study on analyses of proportional reporting ratios-by-therapeutic area

PURPOSE

Disproportionality screening analysis is acknowledged as a tool for performing signal detection in databases of adverse drug reactions (ADRs), e.g., in the European Union (EU) Drug Authority setting. The purpose of this study was to explore the possibility of decreasing false-positive signals of disproportionate reporting (SDR) by calculating the proportional reporting ratio (PRR)-by-therapeutic area (TA), while still maintaining the ability to detect relevant SDRs.

METHODS

In the EudraVigilance (EV) Database, output from PRR calculated with a restricted TA comparator background was compared in detail to output from conventional authority-setting PRR calculations for four drugs: bicalutamide, abiraterone, metformin, and vildagliptin, within the TAs of prostate gland disease and type 2 diabetes mellitus.

RESULTS

ADR reports per investigated drug ranged from 2,400 to 50,000. The PRR-TA's ability to detect true-positive SDRs (as acknowledged in approved labeling) was increased compared to the conventional PRR, and performed 8-31 % better than a recently proposed stricter EU-SDR definition. The PRR-TA removed false SDRs confounded by disease or disease spill-over by up to 63 %, while retaining/increasing the number of unclassified SDRs relevant for manual validation, and thereby improving the ratio between confounded SDRs (i.e., noise) and unclassified SDRs for all investigated drugs (possible signals).

CONCLUSIONS

The performance of the PRR was improved by background restriction with the PRR-TA method; the number of false-positive SDRs decreased, and the ability to detect true-positive SDRs increased, improving the signal-to-noise ratio. Further development and validation of the method is needed within other TAs and databases, and for disproportionality analysis methods.

A potential event-competition bias in safety signal detection: results from a spontaneous reporting research database in France

BACKGROUND

In spontaneous reporting databases, reports of well-established drug-event associations may mask alerts that arise from other drugs (drug competition bias). However, a symmetrical event-competition bias has not yet been explored whereby known events may mask an association with new events for a given drug or drug class.

OBJECTIVE

The objective of this study was to explore the effects of event-competition bias on safety signals generated from spontaneous reporting databases.

METHODS

The drug classes tested included statins, oral anticoagulants, antipsychotics and HIV antiretrovirals. For each, a type A reaction was selected, and its potential competitive effect on the generation of other safety signals for the drug was explored. These were rhabdomyolysis/myopathy for statins, haemorrhage for oral anticoagulants, extrapyramidal syndrome for antipsychotics and lipodystrophy for HIV antiretrovirals. Signals of disproportionate reporting (SDRs) were detected using the case/non-case approach in the French research spontaneous reporting database (which contains reports from 1 January 1986 to 31 December 2001), before and after removing all reports concerning these competitor events. SDRs were considered as potential signals if not reported in the literature before 1 January 2002 but confirmed since.

RESULTS

The whole database included 207,236 reports, 4,355 of which included statins as one of the suspected drugs. The removal of reports of rhabdomyolysis/myopathy concerned 8,425 reports among which 867 involved statins. After this removal, 11 new SDRs appeared for statins that had not been detected initially. Similarly, 15 SDRs were unmasked for oral anticoagulants, six for antipsychotics and nine for HIV antiretrovirals. After literature-based assessment, five of the 41 unmasked SDRs appeared related to potential safety signals confirmed after 2002.

CONCLUSION

This study demonstrated that a masking phenomenon resulting from an event-competition effect could occur when performing signal detection using disproportionality analyses of spontaneous reporting databases. This should be taken into account when routine signal detection is performed.