Delays in the post-marketing withdrawal of drugs to which deaths have been attributed: a systematic investigation and analysis

A Comparison of Signals of Designated Medical Events and Non-designated Medical Events: Results from a Scoping Review

INTRODUCTION AND OBJECTIVE

The European Medicines Agency (EMA) maintains a list of designated medical events (DMEs), events that are inherently serious and are prioritized for signal detection, irrespective of statistical criteria. We have analysed the results of our previously published scoping review to determine whether DME signals differ from those of other adverse events in terms of time to communication and characteristics of supporting reports of suspected adverse drug reactions.

METHODS

For all signals, we obtained the launch year of medicinal products from textbooks or regulatory agencies, extracted the year of the first report in VigiBase and calculated the interval between the first report and communication (time to communication, TTC). We further retrieved the average completeness (via vigiGrade) of the reports in each case series in the years before the communication. We categorised as DME signals those concerning an event in the EMA's list. We described the two groups of signals using medians and interquartile ranges (IQR) and compared them using the Brunner-Munzel test, calculating 95% confidence intervals (95% CI) and P values.

RESULTS

Of 4520 signals, 919 concerned DMEs and 3601 concerned non-DMEs. Signals of DMEs were supported by a median of 15 reports (IQR 6-38 reports) with a completeness score of 0.52 (IQR 0.43-0.62) and signals of non-DMEs by 20 reports (IQR 6-84 reports) with a completeness score of 0.46 (IQR 0.38-0.56). The probability that a random DME signal was supported by fewer reports than non-DME signals was 0.56 (95% CI 0.54-0.58, P < 0.001) and that of one having lower average completeness was 0.39 (95% CI 0.36-0.41, P < 0.001). The median TTCs of DME and non-DME signals did not differ (10 years), but the TTC was as low as 2 years when signals (irrespective of classification) were supported by reports whose average completeness was > 0.80.

CONCLUSIONS

Signals of designated medical events were supported by fewer reports and higher completeness scores than signals of other adverse events. Although statistically significant, the differences in effect sizes between the two groups were small. This suggests that listing certain adverse events as DMEs is not having the expected effect of encouraging a focus on reports of the types of suspected adverse reactions that deserve special attention. Further enhancing the completeness of the reports of suspected adverse drug reactions supporting signals of designated medical events might shorten their time to communication and reduce the number of reports required to support them.

Safety-Related Drug Withdrawals in China Between 1999 and 2021: A Systematic Investigation and Analysis

INTRODUCTION

The Chinese National Medical Products Administration (NMPA) has emphasized proactive pharmacovigilance throughout the product life cycle in recent years. However, the safety-related withdrawal of drugs from the Chinese market has received less attention.

OBJECTIVES

The primary aim of the study was to investigate the context of withdrawing a drug for safety reasons in China (between 1999 and 2021).

METHODS

Withdrawn drugs were first identified from the Chinese NMPA and United States (US) Food and Drug Administration websites and the World Health Organization's (WHO's) consolidated list of products, WHO Drug Information, and WHO Pharmaceuticals Newsletter. We then searched the China National Knowledge Internet database, Chongqing VIP information database, Wanfang database, PubMed, and Google Scholar for drug withdrawal details. We used the Oxford Centre for Evidence-Based Medicine criteria to assess the levels of evidence that support withdrawing a drug.

RESULTS

A total of 30 drugs were withdrawn from the Chinese market between 1999 and 2021. The number of withdrawals increased during the stable Chinese drug surveillance period (2012-2021). Evidence from case-series or case-control studies was primarily used to determine the withdrawals of 16 drugs (53.3%). Fifteen drugs were withdrawn from the markets of China and the US, including five drugs (5/15, 33.3%) that were withdrawn in the same year in China and the US.

CONCLUSIONS

The promulgation of regulations and development of advanced passive and active systems have enhanced pharmacovigilance in China. High-quality evidence, coordination with other regulatory authorities, and communication and information sharing should be strengthened to optimize drug safety surveillance and risk management.

The Role of Advanced Technologies Supplemented with Traditional Methods in Pharmacovigilance Sciences

BACKGROUND

The immediate automatic systemic monitoring and reporting of adverse drug reactions, improving the efficacy is the utmost need of the medical informatics community. The venturing of advanced digital technologies into the health sector has opened new avenues for rapid monitoring. In recent years, data shared through social media, mobile apps, and other social websites has increased manifolds requiring data mining techniques.

OBJECTIVE

The objective of this report is to highlight the role of advanced technologies together with the traditional methods to proactively aid in the early detection of adverse drug reactions concerned with drug safety and pharmacovigilance.

METHODS

A thorough search was conducted on papers and patents regarding pharmacovigilance. All articles with respect to the relevant subject were explored and mined from public repositories such as Pubmed, Google Scholar, Springer, ScienceDirect (Elsevier), Web of Science, etc. Results: The European Union's Innovative Medicines Initiative WEB-RADR project has emphasized the development of mobile applications and social media data for reporting adverse effects. Only relevant data has to be captured through the data mining algorithms (DMAs) as it plays an important role in timely prediction of risk with high accuracy using two popular approaches; the frequentist and Bayesian approach. Pharmacovigilance at the pre-marketing stage is useful for the prediction of adverse drug reactions in the early developmental stage of a drug. Later, post-marketing safety reports and clinical data reports are important to be monitored through electronic health records, prescription-event monitoring, spontaneous reporting databases, etc. Conclusion: The advanced technologies supplemented with traditional technologies are the need of the hour for evaluating a product's risk profile and reducing risk in population especially with comorbid conditions and on concomitant medications.

A review of prospective pathways and impacts of COVID-19 on the accessibility, safety, quality, and affordability of essential medicines and vaccines for universal health coverage in Africa

Background

The ongoing pandemic of coronavirus disease 2019 (COVID-19) has the potential to reverse progress towards global targets. This study examines the risks that the COVID-19 pandemic poses to equitable access to essential medicines and vaccines (EMV) for universal health coverage in Africa.

Methods

We searched medical databases and grey literature up to 2 October 2020 for studies reporting data on prospective pathways and innovative strategies relevant for the assessment and management of the emerging risks in accessibility, safety, quality, and affordability of EMV in the context of the COVID-19 pandemic. We used the resulting pool of evidence to support our analysis and to draw policy recommendations to mitigate the emerging risks and improve preparedness for future crises.

Results

Of the 310 records screened, 134 were included in the analysis. We found that the disruption of the international system affects more immediately the capability of low- and middle-income countries to acquire the basket of EMV. The COVID-19 pandemic may facilitate dishonesty and fraud, increasing the propensity of patients to take substandard and falsified drugs. Strategic regional cooperation in the form of joint tenders and contract awarding, joint price negotiation and supplier selection, as well as joint market research, monitoring, and evaluation could improve the supply, affordability, quality, and safety of EMV. Sustainable health financing along with international technology transfer and substantial investment in research and development are needed to minimize the vulnerability of African countries arising from their dependence on imported EMV. To ensure equitable access, community-based strategies such as mobile clinics as well as fees exemptions for vulnerable and under-served segments of society might need to be considered. Strategies such as task delegation and telephone triage could help reduce physician workload. This coupled with payments of risk allowance to frontline healthcare workers and health-literate healthcare organization might improve the appropriate use of EMV.

Conclusions

Innovative and sustainable strategies informed by comparative risk assessment are increasingly needed to ensure that local economic, social, demographic, and epidemiological risks and potentials are accounted for in the national COVID-19 responses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12992-021-00666-8.

Drug Withdrawal Due to Safety: A Review of the Data Supporting Withdrawal Decision

INTRODUCTION

Several drugs were withdrawn from the market due to safety.

OBJECTIVE

The aim of this study was to describe data supporting drug withdrawal from the market due to safety reasons in countries belonging to the World Health Organization.

METHODS

We analyzed drugs withdrawn from the market between 1990 and 2010. All medicine agencies of the countries belonging to the Program for International Drug Monitoring of the World Health Organization were contacted. To complete data, Medline, reference books and available drug databases were also searched. Information sources on which authorities based their withdrawal were categorized and the average time between the first date of exposure and withdrawal was calculated and stratified.

RESULTS

A total of 133 drugs that met the inclusion/exclusion criteria were withdrawn from the market due to safety reasons in the period reviewed (1990 - 2010). Hepatotoxicity (n=36, 27.1%), cardiac disorders (n=25, 18.8%), hypersensitivity (n=17, 12.8%) and nephrotoxicity (n=14, 9.8%) were the major reasons responsible for 69.2% of all drugs withdrawn. In most cases, Information Sources for drug withdrawal were spontaneous reports and/or case reports (n=86, 64.7%), followed by clinical trials (n=24, 18.0%). The average time between the introduction of a drug and its withdrawal due to safety reasons was 20.3 years (SD±13.8).

CONCLUSION

According to available and published evidence, there is no gold standard to identify risks associated with drug exposure. These findings strengthen the role of different information sources within the drug safety review process.

Pharmaceuticals as a market for "lemons": Theory and practice

Drawing on economic theory and institutional analysis, this paper reframes Akerlof's theory of how a market for lemons operates and argues that each of the many markets for lemons must be studied empirically to document how different stakeholders cope with the problems of information asymmetry, secrecy, and power. Such markets are a new field for sociological analysis. To illustrate, the paper characterizes pharmaceuticals as a multi-tier market of information asymmetry in which actors in each tier have substantial control over how much they disclose about hidden risks of harm. Such a market rewards the production and sale of "lemons." Current incentives and institutional practices reward developing a large number of barely therapeutically innovative drugs and ignoring their often hidden or understated harmful side effects. They reward designing and executing substandard, biased trials that mislead the FDA and regulators abroad to approve new drugs without clear evidence of their degree of harm. Approved drugs are likely to be "lemons" but promoted as "safe and effective." The result is substantial hospitalizations and deaths from adverse drug reactions. A "risk proliferation syndrome" of institutional practices maximizes sales, profits, and exposure to toxic side effects. An "inverse benefit law" of marketing operates as companies try to maximize sales. The probability of benefits decreases but the chances of lemons adverse events do not. The details presented here deepen understanding of how markets for lemons thrive on information asymmetry, secrecy, and power. Lessons can be applied to other markets.

Withdrawn medicines included in the essential medicines lists of 136 countries

BACKGROUND

Essential medicines lists and related policies are intended to meet the priority health needs of populations and their implementation is associated with more appropriate use of medicines. The World Health Organization (WHO) recommends that countries carefully select the medicines to be included in their national essential medicines lists. Lists that are used to prioritize access to important treatments should not include medicines that have been withdrawn elsewhere because of an unfavourable benefit-to-harm balance; however, countries still list and use medicines that have been withdrawn worldwide. The objective of this study was to determine whether the national essential medicines lists of 137 countries include medicines that have been withdrawn in other countries.

METHODS AND FINDINGS

We performed an audit of national essential medicines lists for medicines that had been withdrawn. Medicines withdrawn from worldwide markets between 1953 and 2014 were identified using a systematic review of published literature and regulatory documents. The reviewers used sources including the WHO's database of drugs, PubMed, and the websites of regulatory agencies to obtain information regarding adverse effects associated with the medicines, the year of first withdrawal, markets of withdrawal, and the level of evidence supporting each withdrawal. We recorded the number of countries with a withdrawn medicine included in their national medicines list, the number of withdrawn medicines included in each nation's list, and the number of national essential medicines including each withdrawn medicine. 97 medicines were withdrawn in at least one country but still included in one more national essential medicines list. Of 137 countries with a national essential medicines list, 136 lists included at least one withdrawn medicine, with 54% of the lists containing 5 or fewer withdrawn medicines, and 27% including 10 or more withdrawn medicines. 11 medicines were withdrawn worldwide but still included on at least one national essential medicines list. Countries with longer essential medicines lists had more withdrawn medicines included in their lists.

CONCLUSIONS

This study found that withdrawn medicines are included in all but one national essential medicines list, representing a need for more stringent processes for selecting and removing medicines on these lists. Countries may wish to apply special scrutiny to medicines withdrawn in other nations when selecting medicines to include on their lists.

A Drug Decision Support System for Developing a Successful Drug Candidate Using Machine Learning Techniques

BACKGROUND

Virtual screening of candidate drug molecules using machine learning techniques plays a key role in pharmaceutical industry to design and discovery of new drugs. Computational classification methods can determine drug types according to the disease groups and distinguish approved drugs from withdrawn ones.

INTRODUCTION

Classification models developed in this study can be used as a simple filter in drug modelling to eliminate potentially inappropriate molecules in the early stages. In this work, we developed a Drug Decision Support System (DDSS) to classify each drug candidate molecule as potentially drug or non-drug and to predict its disease group.

METHODS

Molecular descriptors were identified for the determination of a number of rules in drug molecules. They were derived using ADRIANA.Code program and Lipinski's rule of five. We used Artificial Neural Network (ANN) to classify drug molecules correctly according to the types of diseases. Closed frequent molecular structures in the form of subgraph fragments were also obtained with Gaston algorithm included in ParMol Package to find common molecular fragments for withdrawn drugs.

RESULTS

We observed that TPSA, XlogP Natoms, HDon_O and TPSA are the most distinctive features in the pool of the molecular descriptors and evaluated the performances of classifiers on all datasets and found that classification accuracies are very high on all the datasets. Neural network models achieved 84.6% and 83.3% accuracies on test sets including cardiac therapy, anti-epileptics and anti-parkinson drugs with approved and withdrawn drugs for drug classification problems.

CONCLUSION

The experimental evaluation shows that the system is promising at determination of potential drug molecules to classify drug molecules correctly according to the types of diseases.

Clinical Studies on Drug-Drug Interactions Involving Metabolism and Transport: Methodology, Pitfalls, and Interpretation

Many drug-drug interactions (DDIs) are based on alterations of the plasma concentrations of a victim drug due to another drug causing inhibition and/or induction of the metabolism or transporter-mediated disposition of the victim drug. In the worst case, such interactions cause more than tenfold increases or decreases in victim drug exposure, with potentially life-threatening consequences. There has been tremendous progress in the predictability and modeling of DDIs. Accordingly, the combination of modeling approaches and clinical studies is the current mainstay in evaluation of the pharmacokinetic DDI risks of drugs. In this paper, we focus on the methodology of clinical studies on DDIs involving drug metabolism or transport. We specifically present considerations related to general DDI study designs, recommended enzyme and transporter index substrates and inhibitors, pharmacogenetic perspectives, index drug cocktails, endogenous substrates, limited sampling strategies, physiologically-based pharmacokinetic modeling, complex DDIs, methodological pitfalls, and interpretation of DDI information.

Short-acting bronchodilators for the management of acute exacerbations of chronic obstructive pulmonary disease in the hospital setting: systematic review

BACKGROUND

Currently, there is a lack of guidelines for the use of short-acting bronchodilators (SABD) in people admitted to hospital for acute exacerbation of chronic obstructive pulmonary disease (AECOPD), despite routine use in practice and risk of cardiac adverse events.

AIM

To review the evidence that underpins use and optimal dose, in terms of risk versus benefit, of SABD for inpatient management of AECOPD and collate the results for future guidelines.

METHODS

Medline, Embase, the Cochrane Central Register of Controlled Trials, clinicaltrials.gov and International Clinical Trials Registry Platform were searched (inception to November 2017) for published and ongoing studies. Included studies were randomised controlled trials or controlled clinical trials investigating the effect of SABD (β2-agonist and/or ipratropium) on inpatients with a diagnosis of AECOPD. This review was undertaken in accordance with PRISMA guidelines and a pre-defined protocol. Due to heterogeneous methodologies, meta-analysis was not possible so the results were synthesised qualitatively.

RESULTS

Of 1378 studies identified, 10 met inclusion criteria. Narrative synthesis of 10 studies revealed no significant differences in most outcomes of interest relative to dose, delivery via inhaler or nebuliser, and type of β2-agonist used. However, some evidence demonstrated significantly increased cardiac side effects with increased dosage of β2-agonist (45% versus 24%), P<0.05).

CONCLUSION

This review identified a paucity of methodologically rigorous evidence evaluating use of SABD among AECOPD. The available evidence did not identify any additional benefits for participants receiving higher doses of short-acting β2-agonists compared to lower doses, or based on type of delivery method or β2-agonists used. However, there was a small increase in some adverse events for participants using higher doses of β2-agonists.

Impact of a Policy Change on Pharmacists' Reporting of Adverse Drug Reactions

BACKGROUND

Spontaneous reports of adverse drug reactions (ADRs) form an essential component of both drug safety monitoring and patient safety initiatives. Pharmacists are well positioned to report ADRs, but many barriers exist to their doing so. Over the past decade, substantial changes have occurred with regard to drug regulations and medication safety initiatives, and it is possible that knowledge-based interventions may be needed to enhance ADR reporting by pharmacists.

OBJECTIVE

To determine whether ADR reporting behaviours of pharmacists improved after release of a revised policy on the reporting of medication incidents.

METHODS

A telephone survey was administered to pharmacists practising in the Canadian Forces Health Services Group. Self-reported behaviours and perceived barriers related to ADR reporting were compared before and 3 months after the updated policy was released. Accuracy in participants' self-assessed ADR reporting was evaluated using independently derived workload statistics.

RESULTS

During the second survey phase (after release of the revised policy), a greater proportion of respondents reported awareness of institutional policies on ADR reporting and declared that they were able to complete all necessary ADR reports during their assigned work hours. However, the number of ADR reports submitted did not increase. Participants' recall of their ADR reporting behaviour was corroborated by workload data. During the second survey phase, there was a noticeable reduction in the number of free-form comments mentioning lack of staff as a barrier to ADR reporting.

CONCLUSIONS

Release of a more comprehensive policy was not associated with an increase in the number of ADR reports generated by pharmacists in the study setting. Interventions to strengthen the organization's work processes for detection of ADRs and submission of individual ADR reports should be strongly considered, to reinforce and enhance existing ADR reporting behaviours among pharmacists.

Trade Agreements and Direct-to-Consumer Advertising of Pharmaceuticals

There is growing international concern about the risks posed by direct-to-consumer advertising (DTCA) of prescription pharmaceuticals, including via the internet. Recent trade agreements negotiated by the United States, however, incorporate provisions that may constrain national regulation of DTCA. Some provisions explicitly mention DTCA; others enable foreign investors to seek compensation if new regulations are seen to harm their investments. These provisions may thus prevent countries from restricting DTCA or put them at risk of expensive legal action from companies seeking damages due to restrictions on advertising. While the most recent example, the Trans-Pacific Partnership Agreement (TPP), collapsed following US withdrawal in January 2017, early indications of the Trump Administration’s trade policy agenda signal an even more aggressive approach on the part of the United States in negotiating advantages for American businesses. Furthermore, the eleven remaining TPP countries may decide to proceed with the agreement in the absence of the United States, with most of the original text (including the provisions relevant to DTCA) intact.

Post-marketing withdrawal of analgesic medications because of adverse drug reactions: a systematic review

INTRODUCTION

Many analgesics have been withdrawn from the market because of adverse drug reactions. Controversy still surrounds the use of some approved analgesics for pain management. However, the trends and reasons for withdrawal of analgesics when harms are attributed to their use have not been systematically assessed. .

AREAS COVERED

We conducted searches in PubMed; Embase; Google Scholar; clinicaltrials.gov; WHO databases of withdrawn products; websites of the European Medicines Agency, the US Food and Drug Administration, the UK Medicines and Healthcare products Regulatory Agency; Meyler's Side Effects of Drugs; Stephens' Detection of New Adverse Drug Reactions; the Pharmaceutical Manufacturing Encyclopedia; and the Merck Index. We included licensed analgesics that were withdrawn after marketing because of adverse reactions between 1950 and March 2017. We excluded herbal products, non-human medicines, and non-prescription medicines. We used the Oxford Centre for Evidence Based Medicine criteria to document the levels of evidence, and chi-squared tests to compare withdrawal patterns across geographical regions.

EXPERT OPINION

Pharmacovigilance systems in low-resource settings should be strengthened. Greater co-ordination across regulatory authorities in assessing and interpreting the benefit-harm balance of new analgesics should be encouraged. Future reporting of harms in clinical trials of analgesics should follow standardized guidelines.

Accelerating regenerative medicine: the Japanese experiment in ethics and regulation

In 2014, the Japanese National Diet introduced new laws aimed at promoting the clinical translation of stem cells and regenerative medicine. The basic action of these laws is to allow the early introduction of regenerative medicine products into the Japanese market through an accelerated approval process, while providing patients with access to certain types of stem cell and cell-based therapies in the context of private clinical practice. While this framework appears to offer enormous opportunities for the translation of stem cell science, it raises ethical challenges that have not yet been fully explored. This paper critically analyzes this framework with respect to the prioritization of safety over clinical benefit, distributive justice and public trust in science and medicine. It is argued that the framework unfairly burdens patients and strained healthcare systems without any clear benefits, and may undermine the credibility of the regenerative medicine field as it emerges.

Postmarketing withdrawal of human medicinal products because of adverse reactions in animals: a systematic review and analysis

PURPOSE

We have identified human medicinal products for which animal data were used as evidence for withdrawal, determined whether the adverse reactions were reported in humans, established whether confirmatory human studies were conducted, and explored the withdrawal patterns over time.

METHODS

We searched the World Health Organization's Consolidated List of [Medicinal] Products, drug regulatory authorities' websites, PubMed, Google Scholar, and selected textbooks to identify medicinal products withdrawn from 1950 to June 2016. We included medicinal products for which animal data were specifically reported as a reason for withdrawal. We used a checklist adapted from the International Agency for Research on Cancer criteria to rate the evidence.

RESULTS

In 37 cases, evidence from animals was the reason given for withdrawal between 1963 and 2000. Evidence of carcinogenicity was cited in 23 cases (62%). Limited evidence for harms occasioned withdrawal in over 80% of cases. In 11 cases (30%), the adverse drug reactions were subsequently reported in humans. In 5 instances (14%), formal studies were conducted in humans. The median interval to withdrawal following reports of adverse reactions was 2 years (IQR = 1-9 y).

CONCLUSIONS

Regulatory authorities and drug manufacturers are likely to withdraw medicinal products quickly from the market when animal experiments suggest increased risks of cancers or congenital malformations. Human studies are seldom conducted when harms are suspected in animals. Future research should explore better methods of extrapolating harms data from animal research to humans.

From evidence-based medicine to personalized medicine, with particular emphasis on drug-safety monitoring

Nowadays, guidelines are derived from the findings of randomized controlled therapeutic trials. However, an overall significant P value does not exclude that some patients may be harmed by or will not respond to the therapeutic agent being studied. Trials in patients with a low risk of events and/or a limited chance of providing significant differences in therapeutic effects require a large patient population to demonstrate a beneficial effect. Composite efficacy endpoints are often employed to obviate the need for a large patient population when low rates of events or limited therapeutic efficacy are anticipated. Results of randomized controlled therapeutic trials are commonly expressed in terms of relative risk reduction, whereas absolute risk reduction allows the calculation of the "number needed to treat" to prevent an adverse outcome. The number needed to treat is a far more clinically relevant variable than relative risk reduction. The clinician's mission is to match treatment to patient with the goal of achieving optimal therapeutic response. Drug-safety monitoring is also of major importance to avoid exposing patients to irreversible adverse effects. Unfortunately, drug-safety monitoring is often overlooked in routine clinical practice. Finally, the lack of long-term therapeutic data (>5-10 years) is an unsolved dilemma, as most trials are limited to a duration of a few months or years.

Post-marketing drug withdrawals: Pharmacovigilance success, regulatory problems

Modern pharmacovigilance began in the 1960s, since when the subject has grown markedly, interest having particularly increased since 2010. One index of its success is the increasing speed with which serious adverse drug reactions are discovered after marketing of a medicinal product. However, the speed with which products have subsequently been withdrawn as a result of the discovery of serious adverse reactions has not consistently changed. This highlights problems that regulators and manufacturers face when serious reactions are discovered, with difficulties in deciding which of several consequent actions to take: to add specific warnings (cautions) or contraindications to the product label; to issue a Direct Healthcare Professional Communication; to allow informed patients to decide whether they will take the drug; or, in the most serious cases, to withdraw the product or revoke the licence. Conflicts of interest may inhibit decision-making. Recommendations that arise from these observations are that: health professionals and patients should be more vigorously encouraged to report suspected adverse drug reactions; regulatory authorities and drug manufacturers should take quicker confirmatory action when serious suspected adverse drug reactions are reported, even anecdotally, with formal studies to test for causality conducted sooner rather than later, applying lower than usual thresholds for suspicion; temporary suspensions or restrictions could be considered during such assessments; universal guidelines are needed for determining when a drug should be withdrawn if serious adverse drug reactions are suspected; there should be more rigorous monitoring and verification of deaths and reporting of reasons for drop-outs during clinical trials, with more transparency in reporting adverse events and ready access to premarketing clinical study reports; post-marketing drug monitoring systems and medicines regulation in low-to-middle income economies, especially in Africa, where withdrawals are fewer than elsewhere, should be strengthened.

Lack of essential information in spontaneous reports of adverse drug reactions in Catalonia-a restraint to the potentiality for signal detection

PURPOSE

The aim of this study is to analyze the quality of the information contained in the adverse drug reactions (ADR) reports and to describe the magnitude and characteristics of the lacking information.

METHODS

All reports of serious ADR received by the Catalan Center of Pharmacovigilance in 2014 were analyzed using the VigiGrade and a more clinical and qualitative approach.

RESULTS

Up to 824 reports describing serious ADR were included in the study; of them, 503 (61.0%) were sent by health care professionals (HPs) and the remaining 321 (39.0%) came from pharmaceutical companies (PhC). More than 80% of missing variables such as 'onset date' or 'time-to-onset' of the ADR were from PhCs reports. 'Onset of treatment date' was not filled in 28 (22.2%) of the reports including an 'additional monitoring' medicine, and 'end of treatment' date was not completed in 53 of those reports (42.1%). In summary, 39% of the reports involving a black triangle medicine sent by PhCs lacked some essential information such as the onset date of treatment.

CONCLUSIONS

More than one third of the reports coming from manufacturers did not include information that is considered a limiting factor to evaluate any causal relationship, and can be an issue for the detection of safety signals. To take advantage of this huge amount of potentially important information that is almost useless at present, data mining tools and new algorithms should be developed and tested with the aim of finding formulas to deal with a huge amount of low quality data without losing it, nor generating a number of false associations.

Post-Marketing Regulation of Medicines Withdrawn from the Market Because of Drug-Attributed Deaths: An Analysis of Justification

INTRODUCTION

Several medicinal products have been withdrawn from the market because of drug-attributed deaths. However, there has been no investigation of whether such withdrawals were justified, and the extent to which confirmatory studies are used to investigate drug-adverse event relationships when deaths are reported is uncertain. We documented medicinal products withdrawn from the market because of drug-attributed deaths, identified confirmatory studies investigating the drug-adverse event relationships, examined whether withdrawals of medicinal products because of drug-attributed deaths after marketing were justified based on a mechanistic analysis, and examined the trends over time.

METHODS

We searched electronic and non-electronic sources to identify medicinal products that were withdrawn because of drug-attributed deaths. We used a previously published algorithm to examine whether the withdrawals of products were justified. We then searched PubMed and Google Scholar to identify studies investigating the drug-adverse event relationships, used the Oxford Centre for Evidence-Based Medicine criteria to document the levels of evidence, and assessed whether the evidence of an association was confirmed.

RESULTS

We included 83 medicinal products. The reasons for withdrawal appeared to have been justified in 80 cases (96%). The median interval between the first reported adverse reaction that was related to the cause of death and the first reported death was 1 year (interquartile range = 1-3); products were withdrawn sooner when the interval between the first reported relevant adverse reaction and the first death was shorter. Confirmatory studies were conducted in 57 instances (69%), and there was evidence of an association in 52 cases (63%). Four products (5%) were re-introduced after initial withdrawal.

CONCLUSION

Regulatory authorities have been justified in making withdrawal decisions when deaths have been attributed to medicinal products, using the precautionary principle when alternative decisions could have been made. Medicinal products are likely to be quickly withdrawn from the market when there is a short interval to the first reported deaths. The use of an algorithm such as we have used in this study could help to expedite the process of decision making.

Post-marketing withdrawal of anti-obesity medicinal products because of adverse drug reactions: a systematic review

BACKGROUND

We identified anti-obesity medications withdrawn since 1950 because of adverse drug reactions after regulatory approval, and examined the evidence used to support such withdrawals, investigated the mechanisms of the adverse reactions, and explored the trends over time.

METHODS

We conducted searches in PubMed, the World Health Organization database of drugs, the websites of drug regulatory authorities, and selected full texts, and we hand searched references in retrieved documents. We included anti-obesity medications that were withdrawn between 1950 and December 2015 and assessed the levels of evidence used for making withdrawal decisions using the Oxford Centre for Evidence-Based Medicine criteria.

RESULTS

We identified 25 anti-obesity medications withdrawn between 1964 and 2009; 23 of these were centrally acting, via monoamine neurotransmitters. Case reports were cited as evidence for withdrawal in 80% of instances. Psychiatric disturbances, cardiotoxicity (mainly attributable to re-uptake inhibitors), and drug abuse or dependence (mainly attributable to neurotransmitter releasing agents) together accounted for 83% of withdrawals. Deaths were reportedly associated with seven products (28%). In almost half of the cases, the withdrawals occurred within 2 years of the first report of an adverse reaction.

CONCLUSIONS

Most of the drugs that affect monoamine neurotransmitters licensed for the treatment of obesity over the past 65 years have been withdrawn because of adverse reactions. The reasons for withdrawal raise concerns about the wisdom of using pharmacological agents that target monoamine neurotransmitters in managing obesity. Greater transparency in the assessment of harms from anti-obesity medications is therefore warranted.

Worldwide withdrawal of medicinal products because of adverse drug reactions: a systematic review and analysis

We have systematically identified medicinal products withdrawn worldwide because of adverse drug reactions, assessed the level of evidence used for making the withdrawal decisions, and explored the patterns of withdrawals over time. We searched PubMed, the WHO database of withdrawn products, and selected texts. We included products that were withdrawn after launch from 1950 onwards, excluding non-human and over-the-counter medicines. We assessed the levels of evidence on which withdrawals were based using the Oxford Center for Evidence Based Medicine Levels of Evidence. Of 353 medicinal products withdrawn from any country, only 40 were withdrawn worldwide. Anecdotal reports were cited as evidence for withdrawal in 30 (75%) and deaths occurred in 27 (68%). Hepatic, cardiac, and nervous system toxicity accounted for over 60% of withdrawals. In 28 cases, the first withdrawal was initiated by the manufacturer. The median interval between the first report of an adverse drug reaction that led to withdrawal and the first withdrawal was 1 year (range 0-43 years). Worldwide withdrawals occurred within 1 year after the first withdrawal in any country. In conclusion, the time it takes for drugs to be withdrawn worldwide after reports of adverse drug reactions has shortened over time. However, there are inconsistencies in current withdrawal procedures when adverse drug reactions are suspected. A uniform method for establishing worldwide withdrawal of approved medicinal products when adverse drug reactions are suspected should be developed, to facilitate global withdrawals. Rapid synthesis of the evidence on harms should be a priority when serious adverse reactions are suspected.

Post-marketing withdrawal of 462 medicinal products because of adverse drug reactions: a systematic review of the world literature

BACKGROUND

There have been no studies of the patterns of post-marketing withdrawals of medicinal products to which adverse reactions have been attributed. We identified medicinal products that were withdrawn because of adverse drug reactions, examined the evidence to support such withdrawals, and explored the pattern of withdrawals across countries.

METHODS

We searched PubMed, Google Scholar, the WHO's database of drugs, the websites of drug regulatory authorities, and textbooks. We included medicinal products withdrawn between 1950 and 2014 and assessed the levels of evidence used in making withdrawal decisions using the criteria of the Oxford Centre for Evidence Based Medicine.

RESULTS

We identified 462 medicinal products that were withdrawn from the market between 1953 and 2013, the most common reason being hepatotoxicity. The supporting evidence in 72 % of cases consisted of anecdotal reports. Only 43 (9.34 %) drugs were withdrawn worldwide and 179 (39 %) were withdrawn in one country only. Withdrawal was significantly less likely in Africa than in other continents (Europe, the Americas, Asia, and Australasia and Oceania). The median interval between the first reported adverse reaction and the year of first withdrawal was 6 years (IQR, 1-15) and the interval did not consistently shorten over time.

CONCLUSION

There are discrepancies in the patterns of withdrawal of medicinal products from the market when adverse reactions are suspected, and withdrawals are inconsistent across countries. Greater co-ordination among drug regulatory authorities and increased transparency in reporting suspected adverse drug reactions would help improve current decision-making processes.

WITHDRAWN--a resource for withdrawn and discontinued drugs

Post-marketing drug withdrawals can be associated with various events, ranging from safety issues such as reported deaths or severe side-effects, to a multitude of non-safety problems including lack of efficacy, manufacturing, regulatory or business issues. During the last century, the majority of drugs voluntarily withdrawn from the market or prohibited by regulatory agencies was reported to be related to adverse drug reactions. Understanding the underlying mechanisms of toxicity is of utmost importance for current and future drug discovery. Here, we present WITHDRAWN, a resource for withdrawn and discontinued drugs publicly accessible at http://cheminfo.charite.de/withdrawn. Today, the database comprises 578 withdrawn or discontinued drugs, their structures, important physico-chemical properties, protein targets and relevant signaling pathways. A special focus of the database lies on the drugs withdrawn due to adverse reactions and toxic effects. For approximately one half of the drugs in the database, safety issues were identified as the main reason for withdrawal. Withdrawal reasons were extracted from the literature and manually classified into toxicity types representing adverse effects on different organs. A special feature of the database is the presence of multiple search options which will allow systematic analyses of withdrawn drugs and their mechanisms of toxicity.

Correlation between Drug Market Withdrawals and Socioeconomic, Health, and Welfare Indicators Worldwide

The relationship between the number of withdrawn/restricted drugs and socioeconomic, health, and welfare indicators were investigated in a comprehensive review of drug regulation information in the United Nations (UN) countries. A total of of 362 drugs were withdrawn and 248 were restricted during 1950-2010, corresponding to rates of 12.02 ± 13.07 and 5.77 ± 8.69 (mean ± SD), respectively, among 94 UN countries. A socioeconomic, health, and welfare analysis was performed for 33 OECD countries for which data were available regarding withdrawn/restricted drugs. The gross domestic product (GDP) per capita, GDP per hour worked, health expenditure per GDP, and elderly population rate were positively correlated with the numbers of withdrawn and restricted drugs (P < 0.05), while the out-of-pocket health expenditure payment rate was negatively correlated. The number of restricted drugs was also correlated with the rate of drug-related deaths (P < 0.05). The World Bank data cross-validated the findings of 33 OECD countries. The lists of withdrawn/restricted drugs showed markedly poor international agreement between them (Fleiss's kappa = -0.114). Twenty-seven drugs that had been withdrawn internationally by manufacturers are still available in some countries. The wide variation in the numbers of drug withdrawals and restrictions among countries indicates the need to improve drug surveillance systems and regulatory communication networks.

In silico assessment of adverse drug reactions and associated mechanisms

During recent years, various in silico approaches have been developed to estimate chemical and biological drug features, for example chemical fragments, protein targets, pathways, among others, that correlate with adverse drug reactions (ADRs) and explain the associated mechanisms. These features have also been used for the creation of predictive models that enable estimation of ADRs during the early stages of drug development. In this review, we discuss various in silico approaches to predict these features for a certain drug, estimate correlations with ADRs, establish causal relationships between selected features and ADR mechanisms and create corresponding predictive models.

Why are there deadly drugs?

Some drugs eventually have to be removed from the market because of a negative benefit-to-harm ratio, including an excess of mortality. Drug safety is the result of multiple factors, commencing with how clinical trials are designed, the information generated by and/or hidden through these trials, trial analysis by drug regulatory authorities (DRAs) and the amount of information that DRAs choose to release, the amount of published information regarding drug safety, the effectiveness of postmarket surveillance systems in recognizing and reporting adverse drug reactions, and the structure of DRAs such as the United States Food and Drug Administration and its equivalent in other countries. This commentary will look at each of these issues in order to highlight the problems in the current approach to drug safety and finally indicate how some of these deficiencies should be addressed.