Response to Propoxyphene Market Withdrawal: Analgesic Substitutes, Doses, and Adverse Events.

OBJECTIVE: Experts cautioned that patients affected by the November 2010 withdrawal of the opioid analgesic propoxyphene might receive riskier prescriptions. To explore this, we compared drug receipts and outcomes among propoxyphene users before and aftermarket withdrawal. STUDY DESIGN: Using OptumLabs data, we studied 3 populations: commercial, Medicare Advantage (MA) aged (age 65+ y) and MA disabled (age below 65 y) enrollees. The exposed enrollees received propoxyphene in the 3 months before market withdrawal (n=13,622); historical controls (unexposed) received propoxyphene 1 year earlier (n=9971). Regression models estimated daily milligrams morphine equivalent (MME), daily prescription acetaminophen dose, potentially toxic acetaminophen doses, nonopioid prescription analgesics receipt, emergency room visits, and diagnosed falls, motor vehicle accidents, and hip fractures. PRINCIPAL FINDINGS: Aged MA enrollees illustrate the experience of all 3 populations examined. Following the market withdrawal, propoxyphene users in the exposed cohort experienced an abrupt decline of 69% in average daily MME, compared with a 14% decline in the unexposed. Opioids were discontinued by 34% of the exposed cohort and 18% of the unexposed. Tramadol and hydrocodone were the most common opioids substituted for propoxyphene. The proportion of each group receiving ≥4 g of prescription acetaminophen per day decreased from 12% to 2% in the exposed group but increased from 6% to 8% among the unexposed. Adverse events were rare and not significantly different in exposed versus unexposed groups. CONCLUSIONS: After propoxyphene market withdrawal, many individuals experienced abrupt discontinuation of opioids. Policymakers might consider supporting appropriate treatment transitions and monitoring responses following drug withdrawals.

Secret safety warnings on medicines: A case study of information access requests.

PURPOSE: There has been less attention to the transparency of postmarket evidence of harmful effects of medicines than of premarket clinical trial data. This is a case study of requests for Australian "direct health professional communications" (DHPCs). These letters are used by regulators and manufacturers to inform clinicians of emergent evidence of harm. DHPCs are not made public by Australia's Therapeutic Goods Administration (TGA). METHODS: We requested all DHPCs sent out in Australia from 2007 to 2016 inclusive for 207 drugs that were subject to safety advisories over this decade in Canada, the United Kingdom, and/or the United States. We contacted 39 manufacturers (February to May 2018), with repeat requests to nonrespondents, and a follow-up freedom-of-information (FOI) request to the TGA. RESULTS: Fifteen companies provided information, either sending DHPCs (n = 4, on five drugs) or affirming none were sent out (n = 11). The remaining 24 of 39 (62%) companies did not provide DHPCs: nine (23%) refused the request, often citing commercial confidentiality; the rest provided no answer despite repeat requests. In total, we had no information for 170 of 207 (82%) of the drugs. Our FOI request to the TGA was unsuccessful. CONCLUSIONS: Our experience highlights unacceptable secrecy concerning safety warnings previously sent to thousands of Australian clinicians. In the absence of explicit regulatory policy supporting disclosure, companies differed in their response. These letters warn of serious and often life-threatening harm and guide safer care; full ongoing public access is needed, ideally in searchable online databases.

Moulds associated with contaminated ocular and injectable drugs: FDA recalls, epidemiology considerations, drug shortages, and aseptic processing.

Recent (2012) grave but rare outbreaks of fungal meningitis and endophthalmitis associated with drugs contaminated with select environmental moulds (Exserohilum and Fusarium, respectively) have exacerbated mycology concerns for formulation, good laboratory practices (GLP), and use of the final drug product. Intensified investigations (2013-2015) by the Food and Drug Administration (FDA) that included added responsibilities for specialty compounding laboratories have prompted at least nine voluntary mould-related drug recalls during 2014-2015. Both primary manufactures (five recalls, two companies) and secondary-processing compound laboratories (at least eight recalls, six companies) and near 0.8 million units were involved. These constituted minor fractions of recalled drug products in an estimated 2500 recalls among other causes during this time period. Recalls of similar drugs in 2016 were indirectly related to fungi. None of the mould-related- drug-recall episodes during 2014-2016 have been identified with fungal disease outbreaks. The recalls included drugs in short supply worldwide such as injectable sodium chloride- and related saline solutions as well as ocular formulations. Insufficient environmental monitoring and GLP compliance, particularly for aseptic processing of non-preserved formulations, appeared to be underlying factors in the fungal contaminations. Observations of mould growth in drugs during their processing should be accurately recorded and investigated; cryptic listings under "particulate" designations should be avoided. Confirmed identifications for chronic contaminants are recommended. Heat-tolerant moulds with resistant morphotypes are prime concerns.

Analysis of factors related to the occurrence of important drug-specific postmarketing safety-related regulatory actions: A cohort study focused on first-in-class drugs.

PURPOSE: First-in-class (FIC) drugs with novel modes of action pose concerns regarding important postmarketing safety issues. The purpose of this study was to analyze the factors related to the occurrence of postmarketing safety-related regulatory actions (PSRAs) for drugs approved in the United States (US), with a focus on FIC drugs. METHODS: New molecular entities and new therapeutic biologics approved in the United States between 1 January 2003 and 31 December 2013 were included in the analysis. Important drug-specific PSRAs were defined as market withdrawal or the addition of new black box warnings or warnings due to adverse drug reactions. The relationship between baseline characteristics and the occurrence of important drug-specific PSRAs was investigated using a multivariate logistic regression model. We also defined the event as the first important PSRA and estimated the time-to-event for each factor. RESULTS: ATC category L (antineoplastic and immunomodulating agents) and FIC drug classification were shown to be statistically significant factors, with odds ratios of 2.15 (95% CI: 1.12-4.11; P = 0.0203) and 1.87 (95% CI: 1.06-3.31; P = 0.0309), respectively. ATC category L and FIC drugs were also significant factors for time to occurrence of the first event. CONCLUSION: FIC designation and ATC category L were identified as factors related to important drug-specific PSRAs. These factors were also associated with the time to occurrence of the first important drug-specific PSRAs.

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.

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.

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.

Drug safety: withdrawn medications are only part of the picture.

In a research article published in BMC Medicine, Onakpoya and colleagues provide a historical review of withdrawals of medications for safety reasons. However, withdrawn medications are only one part of the picture about how regulatory agencies manage drug risks. Moreover, medications introduced before the increased pre-marketing regulations and post-marketing monitoring systems instituted after the thalidomide tragedy have little relevance when considering the present drug safety picture because the circumstances under which they were introduced were completely different. To more fully understand drug safety management and regulatory agency actions, withdrawals should be evaluated within the setting and timeframe in which the medications are approved, which requires information about approvals and safety warnings. Studies are needed that provide a more comprehensive current picture of the identification and evaluation of drug safety risks as well as how regulatory agencies deal with them. Please see related research article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0553-2.

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.

Disparities in Discontinuing Rosiglitazone Following the 2007 FDA Safety Alert.

BACKGROUND: Responsiveness to the Food and Drug Administration (FDA) rosiglitazone safety alert, issued on May 21, 2007, has not been examined among vulnerable subpopulations of the elderly. OBJECTIVE: To compare time to discontinuation of rosiglitazone after the safety alert between black and white elderly persons, and across sociodemographic and economic subgroups. RESEARCH DESIGN: A cohort study. SUBJECTS: Medicare fee-for-service enrollees in 2007 who were established users of rosiglitazone identified from a 20% national sample of pharmacy claims. MEASURES: Outcome of interest was time to discontinuation of rosiglitazone after the May alert. We modeled the number of days following the warning to the end of the days' supply for the last rosiglitazone claim during the study period (May 21, 2007-December 31, 2007) using multivariable proportional hazards models. RESULTS: More than 67% of enrollees discontinued rosiglitazone within six months of the advisory. In adjusted analysis, white enrollees (hazard ratio=0.90; 95% confidence interval, 0.86-0.94) discontinued rosiglitazone later than the comparison group of black enrollees. Enrollees with a history of low personal income also discontinued later than their comparison group (hazard ratio=0.84; 95% confidence interval, 0.81-0.87). There were no observed differences across quintiles of area-level socioeconomic status. CONCLUSIONS: White race and a history of low personal income modestly predicted later discontinuation of rosiglitazone after the FDA's safety advisory in 2007. The impact of FDA advisories can vary among sociodemographic groups. Policymakers should continue to monitor whether risk management policies reach their intended populations.

Bullous pemphigoid and dipeptidyl peptidase IV inhibitors: a case-noncase study in the French Pharmacovigilance Database.

BACKGROUND: Inhibitors of dipeptidyl peptidase (DPP)-IV have been suspected in the onset of bullous pemphigoid for several years now. However, comparative studies assessing the link between DPP-IV inhibitor exposure and bullous pemphigoid have not yet been performed. OBJECTIVES: To detect, from the French Pharmacovigilance Database (FPVD), a signal of risk of bullous pemphigoid during DPP-IV inhibitor exposure by comparative study. METHODS: All spontaneous reports of DPP-IV inhibitor-related bullous pemphigoid recorded in the FPVD between April 2008 and August 2014 were described. We conducted disproportionality analyses (case-noncase method) to assess the link between DPP-IV inhibitors and bullous pemphigoid, calculating reporting odds ratios (RORs). We also compared DPP-IV inhibitor-induced bullous pemphigoid reports rated per million defined daily doses dispensed during the study period. RESULTS: Among 217 331 spontaneous adverse drug reaction reports registered in the FPVD, 1297 involved DPP-IV inhibitors. Among these observations, 42 were bullous pemphigoid (vildagliptin, n = 31; sitagliptin, n = 10; saxagliptin, n = 1). The ROR for pooled DPP-IV inhibitors was 67·5 [95% confidence interval (CI) 47·1-96·9]. Disproportionality was also observed for each DPP-IV inhibitor: vildagliptin (ROR 225·3, 95% CI 148·9-340·9), sitagliptin (ROR 17·0, 95% CI 8·9-32·5) and saxagliptin (ROR 16·5, 95% CI 2·3-119·1). Analyses adjusted on dispensing data led to similar results. CONCLUSIONS: These data confirm a strong signal for an increased risk of bullous pemphigoid during DPP-IV inhibitor exposure. This adverse drug reaction is observed for each DPP-IV inhibitor, suggesting a class effect. The signal was higher with vildagliptin than with the other DPP-IV inhibitors.

Benefit-risk reassessment of medicines: a retrospective analysis of all safety-related referral procedures in Europe during 2001-2012.

PURPOSE: The aim of this study was to determine the outcomes and timing within the product life cycle of all benefit-risk reassessment procedures for marketed products that were completed by the committee for medicinal product for human use during 2001-2012. METHODS: A cohort of all referral procedures for benefit-risk reassessment (Article 20, Article 31, Article 36, Article 107 procedures) for which committee for medicinal product for human use issued an opinion between 1 January 2001 and 31 December 2012 was created. The European Medicines Agency website and the Dutch Medicines Evaluation Board website were used to collect all data. RESULTS: There were a total of 73 benefit-risk reassessments during the study period; 61 reassessments for a single product and 12 reassessments for multiple products or an entire product class. Nineteen reassessments resulted in the recommendation to remove the product from the market. On average, a benefit-risk reassessment was performed 18.7 years after the product was first marketed. Seventeen products were marketed 5 years or less when the reassessment procedure was completed; six of these products were subsequently removed from the market. CONCLUSIONS: The majority of all benefit-risk reassessments that were performed during the study period did not result in removing the product from the market, but rather, in confirming the positive benefit-risk of the product, conditional to changes to the product's marketing authorisation. About half of all products that were removed from the market during the 2000s had been marketed for more than 20 years. Copyright © 2016 John Wiley & Sons, Ltd.

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

BACKGROUND: Post-marketing withdrawal of medicinal products because of deaths can be occasioned by evidence obtained from case reports, observational studies, randomized trials, or systematic reviews. There have been no studies of the pattern of withdrawals of medicinal products to which deaths have been specifically attributed and the evidence that affects such decisions. Our objectives were to identify medicinal products that were withdrawn after marketing in association with deaths, to search for the evidence on which withdrawal decisions were based, and to analyse the delays involved and the worldwide patterns of withdrawal. METHODS: We searched the World Health Organization's Consolidated List of [Medicinal] Products, drug regulatory authorities' websites, PubMed, Google Scholar, and textbooks on adverse drug reactions. We included medicinal products for which death was specifically mentioned as a reason for withdrawal from the market. Non-human medicines, herbal products, and non-prescription medicines were excluded. One reviewer extracted the data and a second reviewer verified them independently. RESULTS: We found 95 drugs for which death was documented as a reason for withdrawal between 1950 and 2013. All were withdrawn in at least one country, but at least 16 remained on the market in some countries. Withdrawals were more common in European countries; few were recorded in Africa (5.3%). The more recent the launch date, the sooner deaths were reported. However, in 47% of cases more than 2 years elapsed between the first report of a death and withdrawal of the drug, and the interval between the first report of a death attributed to a medicinal product and eventual withdrawal of the product has not improved over the last 60 years. CONCLUSIONS: These results suggest that some deaths associated with these products could have been avoided. Manufacturers and regulatory authorities should expedite investigations when deaths are reported as suspected adverse drug reactions and consider early suspensions. Increased transparency in the publication of clinical trials data and improved international co-ordination could shorten the delays in withdrawing dangerous medicinal products after reports of deaths and obviate discrepancies in drug withdrawals in different countries.

Post-market safety warnings for drugs approved in Canada under the Notice of Compliance with conditions policy.

AIMS: Health Canada has developed a pathway to approve drugs that have limited efficacy and safety data, the Notice of Compliance with conditions (NOC/c) policy. Increased safety reporting is required for these drugs but there has not been any systematic review of their post-market safety. This study compares safety warnings for NOC/c drugs with drugs with a priority and a standard review. METHODS: A list of drugs approved between January 1 1998 and March 31 2013 was developed and serious safety warnings for these drugs were identified. Drugs were put into one of three groups based on the way that they were approved. Kaplan-Meier curves were generated to examine the likelihood of NOC/c drugs receiving a serious safety warning compared with drugs with a priority and a standard review. The time spent in the review process for each of the groups was also measured. RESULTS: Compared with drugs with a priority review, NOC/c drugs were not more likely to receive a serious safety warning (P = 0.5940) but were more likely than drugs with a standard review (P = 0.0113). NOC/c drugs spent less time in the review process compared with drugs with a standard review. CONCLUSIONS: Possible reasons for the increase likelihood of a serious safety warning are the limited knowledge of the safety of NOC/c drugs when they are approved and the length of time that they spend in the review process. Health Canada should consider spending longer reviewing these drugs and monitor their post-market safety more closely.

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.

Market withdrawal of new molecular entities approved in the United States from 1980 to 2009.

PURPOSE: Economic factors, market dynamics, and safety issues are largely responsible for decisions to withdraw pharmaceutical products from the market. In this study, new molecular entities (NMEs) approved by the Food and Drug Administration (FDA) were examined in the USA from 1980 to 2009. METHODS: Data were obtained from the FDA, Micromedex, Medline, and Lexis-Nexis. Descriptive analyses were used to classify product discontinuations by therapeutic category, time frame for discontinuation, and reason for withdrawal. RESULTS: There were 740 NMEs approved by the FDA during the study period. As of 1 December 2010, the number of drugs discontinued was 118 (15.9%). Discontinuations were the highest for antiparasitic products, insecticides, and repellents (6, 33.3% of approvals), systemic hormonal preparations excluding sex hormones and insulins (5, 33.3%), musculo-skeletal system (11, 32.4%), diagnostic agents (16, 28.1%), and anti-infectives for systemic use (27, 25.2%). Safety was the primary reason for withdrawing 26 drugs (3.5% of approvals). CONCLUSIONS: Approximately one in seven approved NMEs were discontinued from the market in the period of 1980-2009. Less than one-quarter (22%) of the total withdrawals were attributed to safety reasons. An ongoing evaluation of new drugs throughout their product life cycle is important to determine their efficacy, safety, and value to society.

Regulatory and clinical consequences of negative confirmatory trials of accelerated approval cancer drugs: retrospective observational study.

OBJECTIVES: To investigate the regulatory handling of cancer drugs that were granted accelerated approval by the US Food and Drug Administration (FDA) but failed to improve the primary endpoint in post-approval trials and to evaluate the extent to which negative post-approval trials changed the recommendations in treatment guidelines. DESIGN: Retrospective observational study. SETTING: FDA and National Comprehensive Cancer Network (NCCN) reports. INCLUDED DRUGS: Cancer drugs that received accelerated approval from the FDA and had negative post-approval trials. MAIN OUTCOME MEASURES: Regulatory outcomes, including withdrawal, conversion to regular approval, and no action. RESULTS: 18 indications for 10 cancer drugs that received accelerated approval but failed to improve the primary endpoint in post-approval trials were identified. Of these, 11 (61%) were voluntarily withdrawn by the manufacturer and one (bevacizumab for breast cancer) was revoked by the FDA. Of the 11 withdrawals, six occurred in 2021 alone. The remaining six (33%) indications remain on the label. The NCCN guidelines provide a high level of endorsement (category 1 endorsement for one and category 2A endorsement for seven) for accelerated approval drugs that have failed post-approval trials, sometimes even after the approval has been withdrawn or revoked. CONCLUSION: Cancer drug indications that received accelerated approval often remained on formal FDA approved drug labelling and continued to be recommended in clinical guidelines several years after statutorily required post-approval trials showed no improvement in the primary efficacy endpoint. Clinical guidelines should better align with the results of post-approval trials of cancer drugs that received accelerated approval.

Toward a broader view of mechanisms of drug cardiotoxicity.

Cardiotoxicity, defined as toxicity that affects the heart, is one of the most common adverse drug effects. Numerous drugs have been shown to have the potential to induce lethal arrhythmias by affecting cardiac electrophysiology, which is the focus of current preclinical testing. However, a substantial number of drugs can also affect cardiac function beyond electrophysiology. Within this broader sense of cardiotoxicity, this review discusses the key drug-protein interactions known to be involved in cardiotoxic drug response. We cover adverse effects of anticancer, central nervous system, genitourinary system, gastrointestinal, antihistaminic, anti-inflammatory, and anti-infective agents, illustrating that many share mechanisms of cardiotoxicity, including contractility, mitochondrial function, and cellular signaling.

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.