Complications and Management of Eptifibatide-Induced Thrombocytopenia

BACKGROUND

Eptifibatide is used in acute coronary syndromes to reversibly block platelet aggregation by inhibiting the platelet glycoprotein IIb/IIIa receptor. A serious adverse effect of eptifibatide is a profound drop in platelet count, termed eptifibatide-induced thrombocytopenia (EIT).

OBJECTIVE

To provide insight into the types of complications and management of EIT.

METHODS

Cases of EIT submitted to the Food and Drug Administration adverse event reporting system were evaluated. Data analyses included management of EIT, complications of thrombocytopenia, initial platelets, and platelet nadir following eptifibatide.

RESULTS

103 cases of EIT were reported from January 2010 to 2019; 57 cases met the Naranjo scale and were included. Only 37 of those cases contained information on how EIT was managed. Eptifibatide administration was withheld in all 37 of those cases. Platelet transfusions were administered in 20 cases (54%). Two cases were managed with steroids (5.4%), and 1 case used intravenous immunoglobulin G to reverse EIT (2%). The median initial platelet count prior to administration of eptifibatide was 207 000 cells/mm³ (SD = 69 000; n = 27), and median platelet nadir was 9000 cells/mm³ (SD = 19 000; n = 35) The majority of complications of EIT included bleeding events (16/28, 57%). Delayed procedures, prolonged stay, allergic reactions, and thrombosis were each reported in 3 patients (10.75%).

CONCLUSION AND RELEVANCE

Most cases of EIT were managed by withholding eptifibatide with platelet transfusion if necessary. The majority of complications included bleeding. However, significant procedure delays, prolonged hospital stay, thrombosis, and allergic reactions were also reported.

Multicenter Safety and Practice for Off-Label Diagnostic Use of Ferumoxytol in MRI

Background Ferumoxytol is approved for use in the treatment of iron deficiency anemia, but it can serve as an alternative to gadolinium-based contrast agents. On the basis of postmarketing surveillance data, the Food and Drug Administration issued a black box warning regarding the risks of rare but serious acute hypersensitivity reactions during fast high-dose injection (510 mg iron in 17 seconds) for therapeutic use. Whereas single-center safety data for diagnostic use have been positive, multicenter data are lacking. Purpose To report multicenter safety data for off-label diagnostic ferumoxytol use. Materials and Methods The multicenter ferumoxytol MRI registry was established as an open-label nonrandomized surveillance databank without industry involvement. Each center monitored all ferumoxytol administrations, classified adverse events (AEs) using the National Cancer Institute Common Terminology Criteria for Adverse Events (grade 1-5), and assessed the relationship of AEs to ferumoxytol administration. AEs related to or possibly related to ferumoxytol injection were considered adverse reactions. The core laboratory adjudicated the AEs and classified them with the American College of Radiology (ACR) classification. Analysis of variance was used to compare vital signs. Results Between January 2003 and October 2018, 3215 patients (median age, 58 years; range, 1 day to 96 years; 1897 male patients) received 4240 ferumoxytol injections for MRI. Ferumoxytol dose ranged from 1 to 11 mg per kilogram of body weight (≤510 mg iron; rate ≤45 mg iron/sec). There were no systematic changes in vital signs after ferumoxytol administration (P > .05). No severe, life-threatening, or fatal AEs occurred. Eighty-three (1.9%) of 4240 AEs were related or possibly related to ferumoxytol infusions (75 mild [1.8%], eight moderate [0.2%]). Thirty-one AEs were classified as allergiclike reactions using ACR criteria but were consistent with minor infusion reactions observed with parenteral iron. Conclusion Diagnostic ferumoxytol use was well tolerated, associated with no serious adverse events, and implicated in few adverse reactions. Registry results indicate a positive safety profile for ferumoxytol use in MRI. © RSNA, 2019 Online supplemental material is available for this article.

A Pharmacovigilance Signaling System Based on FDA Regulatory Action and Post-Marketing Adverse Event Reports

INTRODUCTION

Many serious drug adverse events (AEs) only manifest well after regulatory approval. Therefore, the development of signaling methods to use with post-approval AE databases appears vital to comprehensively assess real-world drug safety. However, with millions of potential drug-AE pairs to analyze, the issue of focus is daunting.

OBJECTIVE

Our objective was to develop a signaling platform that focuses on AEs with historically demonstrated regulatory interest and to analyze such AEs with a disproportional reporting method that offers broad signal detection and acceptable false-positive rates.

METHODS

We analyzed over 1500 US FDA regulatory actions (safety communications and drug label changes) from 2008 to 2015 to construct a list of eligible signal AEs. The FDA Adverse Event Reporting System (FAERS) was used to evaluate disproportional reporting rates, constrained by minimum case counts and confidence interval limits, of these selected AEs for 109 training drugs. This step led to 45 AEs that appeared to have a low likelihood of being added to a label by FDA, so they were removed from the signal eligible list. We measured disproportional reporting for the final group of eligible AEs on a test group of 29 drugs that were not used in either the eligible list construction or the training steps.

RESULTS

In a group of 29 test drugs, our model reduced the number of potential drug-AE signals from 41,834 to 97 and predicted 73 % of individual drug label changes. The model also predicted at least one AE-drug pair label change in 66 % of all the label changes for the test drugs.

CONCLUSIONS

By concentrating on AE types with already demonstrated interest to FDA, we constructed a signaling system that provided focus regarding drug-AE pairs and suitable accuracy with regard to the issuance of FDA labeling changes. We suggest that focus on historical regulatory actions may increase the utility of pharmacovigilance signaling systems.

Can Disproportionality Analysis of Post-marketing Case Reports be Used for Comparison of Drug Safety Profiles?

Clinical trials usually do not have the power to detect rare adverse drug reactions. Spontaneous adverse reaction reports as for example available in post-marketing safety databases such as the FDA Adverse Event Reporting System (FAERS) are therefore a valuable source of information to detect new safety signals early. To screen such large data-volumes for safety signals, data-mining algorithms based on the concept of disproportionality have been developed. Because disproportionality analysis is based on spontaneous reports submitted for a large number of drugs and adverse event types, one might consider using these data to compare safety profiles across drugs. In fact, recent publications have promoted this practice, claiming to provide guidance on treatment decisions to healthcare decision makers. In this article we investigate the validity of this approach. We argue that disproportionality cannot be used for comparative drug safety analysis beyond basic hypothesis generation because measures of disproportionality are: (1) missing the incidence denominators, (2) subject to severe reporting bias, and (3) not adjusted for confounding. Hypotheses generated by disproportionality analyses must be investigated by more robust methods before they can be allowed to influence clinical decisions.

Relative Incidence of Acute Adverse Events with Ferumoxytol Compared to Other Intravenous Iron Compounds: A Matched Cohort Study

Concerns persist about adverse reactions to intravenous (IV) iron. We aimed to determine the relative safety of ferumoxytol compared to other IV iron compounds. This retrospective cohort study with propensity-score matching for patients and drug doses used the Medicare 20% random sample to identify patients (1) without chronic kidney disease (non-CKD) and (2) with non-dialysis-dependent chronic kidney disease (NDD-CKD) who received a first dose of IV iron in 2010-2012. Exposures were ferumoxytol, iron sucrose, sodium ferric gluconate, or iron dextran. Outcomes were hypersensitivity symptoms, anaphylaxis, emergency department (ED) encounters, hospitalizations, and death after acute IV iron exposure. In the primary analysis for reactions on the day of or following exposure, there was no difference in hypersensitivity symptoms (hazard ratio 1.04, 95% confidence interval 0.94-1.16) or hypotension (0.83, 0.52-1.34) between 4289 non-CKD ferumoxytol users and an equal number of users of other compounds; results were similar for 7358 NDD-CKD patients and an equal number of controls. All-cause ED encounters or hospitalizations were less common in both the non-CKD (0.56, 0.45-0.70) and NDD-CKD ferumoxytol-treated patients (0.83, 0.71-0.95). Fewer than 10 deaths occurred in both the non-CKD and NDD-CKD ferumoxytol users and in matched controls; the hazard for death did not differ significantly between ferumoxytol users and controls in the non-CKD patients (2.00, 0.33-11.97) or in the NDD-CKD patients (0.25, 0.04-1.52). Multiple sensitivity analyses showed similar results. Ferumoxytol did not appear to be associated with more adverse reactions than other compounds for the treatment of iron-deficiency anemia in both non-CKD and NDD-CKD patients.

A Drug Safety Rating System Based on Postmarketing Costs Associated with Adverse Events and Patient Outcomes

BACKGROUND

Given the multiple limitations associated with relatively homogeneous preapproval clinical trials, inadequate data disclosures, slow reaction times from regulatory bodies, and deep-rooted bias against disclosing and publishing negative results, there is an acute need for the development of analytics that reflect drug safety in heterogeneous, real-world populations.

OBJECTIVE

To develop a drug safety statistic that estimates downstream medical costs associated with serious adverse events (AEs) and unfavorable patient outcomes associated with the use of 706 FDA-approved drugs.

METHODS

All primary suspect case reports for each drug were collected from the FDA's Adverse Event Reporting System database (FAERS) from 2010-2014. The Medical Dictionary for Regulatory Activities (MedDRA) was used to code serious AEs and outcomes, which were tallied for each case report. Medical costs associated with AEs and poor patient outcomes were derived from Agency for Healthcare Research and Quality (AHRQ) survey data, and their corresponding ICD-9-CM codes were mapped to MedDRA terms. Nonserious AEs and outcomes were not included. For each case report, either the highest AE cost or, if no eligible AE was listed, the highest outcome cost was used. All costed cases were aggregated for each drug and divided by the number of patients exposed to obtain a downstream estimated direct medical cost burden per exposure. Each drug was assigned a corresponding 1-100 point total.

RESULTS

The 706 drugs showed an exponential distribution of downstream costs, and the data were transformed using the natural log to approximate a normal distribution. The minimum score was 8.29, and the maximum score was 99.25, with a mean of 44.32. Drugs with the highest individual scores tended to be kinase inhibitors, thalidomide analogs, and endothelin receptor antagonists. When scores were analyzed across Established Pharmacologic Class (EPC), the kinase inhibitor and endothelin receptor antagonist classes had the highest total. However, other EPCs with median scores of 75 and above included hepatitis C virus NS3/4A protease inhibitor, recombinant human interferon beta, vascular endothelial growth factor-directed antibody, and tumor necrosis factor blocker. When Anatomical Therapeutic Chemical classifications were analyzed, antineoplastic drugs were outliers with approximately 80% of their individual scores 60 and above, while approximately 20%-30% of blood and anti-infective drugs had scores of 60 and above. Within-drug class results served to differentiate similar drugs. For example, 6 serotonin reuptake inhibitors had a score range of 35 to 53.

CONCLUSIONS

This scoring system is based on estimated direct medical costs associated with postmarketing AEs and poor patient outcomes and thereby helps fill a large information gap regarding drug safety in real-world patient populations.

Safety and efficacy of rapid (1,000 mg in 1 hr) intravenous iron dextran for treatment of maternal iron deficient anemia of pregnancy

Maternal iron deficiency anemia (IDA) is associated with risk of adverse perinatal outcomes. Oral iron is recommended to reverse anemia, but has gastrointestinal toxicity and frequent non-adherence. Intravenous (IV) iron is reserved for intolerance of, or unresponsiveness to, oral therapy, malabsorption, and severe anemia (1% with hemoglobin [Hgb] levels <7 g/dL). With rare (<100 per one million) adverse events (AEs) ability to infuse a sufficient dose of low molecular weight iron dextran (LMWID) over 60 min, LMWID is an attractive option. This study demonstrated safety and efficacy of rapid IV infusion of 1,000 mg LMWID to gravidas with moderate to severe IDA. An observational treatment study of 1,000 mg LMWID administered over 1 hr for IDA in 189 consecutive, unselected second and third trimester gravidas after oral iron failure was conducted. All received a test dose of 25 mg LMWID and were monitored for AEs during the 60-min infusion. No premedication was administered unless more than one drug allergy or asthma was present in which case IV methylprednisolone was administered. All were followed through pregnancy and delivery. Monitored parameters included Hgb, mean corpuscular volume, serum ferritin, and percent transferrin saturation. About 189 subjects received 1,000 mg LMWID. No serious AEs occurred. About 2% experienced transient infusion reactions. Hgb improved by 1-1.9 g/dL in 82% and ≥2 g/dL in 24%. Second trimester treatment was not associated with greater Hgb improvement than third trimester treatment. Anemia resolved in 95%. Administration of a single large dose of IV LMWID was effective, safe, and convenient. Am. J. Hematol. 91:590-593, 2016. © 2016 Wiley Periodicals, Inc.

Adverse event reporting patterns of newly approved drugs in the USA in 2006: an analysis of FDA Adverse Event Reporting System data

BACKGROUND

The Weber effect states that adverse event (AE) reporting tends to increase in the first 2 years after a new drug is placed onto the market, peaks at the end of the second year, and then declines. However, since the Weber effect was originally described, there has been improvement in the communication of safety information and new policies regarding the reporting of AEs by healthcare professionals and consumers, prompting reassessment of the existence of the Weber effect in the current AE reporting scenario.

OBJECTIVES

To determine the AE reporting patterns for new molecular entity (NME) drugs and biologics approved in 2006 and to examine these patterns for the existence of the Weber effect.

METHODS

Publicly available FDA Adverse Event Reporting System data were used to assess the AE reporting patterns for a 5-year period from the drug’s approval date. The total number of annual reports from all sources, based on the report date, was plotted against time (in years).

RESULTS

In the period from 2006 to 2011, a total of 91,187 AE reports were submitted for 19 NMEs approved in 2006. The highest number of AE reports were submitted for varenicline tartrate (N = 47,158) and the lowest number for anidulafungin (N = 161). Anidulafungin was reported to have the highest proportion of death reports (36 %) and varenicline tartrate the lowest proportion (1.7 %). The classic Weber pattern was not observed for any of the 19 NMEs approved in 2006. While there was no one predominant pattern of AE report volume, we grouped the drugs into four general categories; the majority of drugs had either a continued increase in reports (Category A 31.6 %) or an N-pattern with reporting reaching an initial peak in year 2 or 3, declining and then beginning to climb again (Category B 42.1 %).

CONCLUSIONS AND RELEVANCE

There have been numerous changes in AE reporting, particularly a huge increase in overall annual report volume, since the Weber effect was first reported. Our results suggest that a Weber-type reporting pattern should not be assumed in the design or interpretation of analyses based on AE reports.

Commonality of drug-associated adverse events detected by 4 commonly used data mining algorithms

OBJECTIVES

Data mining algorithms have been developed for the quantitative detection of drug-associated adverse events (signals) from a large database on spontaneously reported adverse events. In the present study, the commonality of signals detected by 4 commonly used data mining algorithms was examined.

METHODS

A total of 2,231,029 reports were retrieved from the public release of the US Food and Drug Administration Adverse Event Reporting System database between 2004 and 2009. The deletion of duplicated submissions and revision of arbitrary drug names resulted in a reduction in the number of reports to 1,644,220. Associations with adverse events were analyzed for 16 unrelated drugs, using the proportional reporting ratio (PRR), reporting odds ratio (ROR), information component (IC), and empirical Bayes geometric mean (EBGM).

RESULTS

All EBGM-based signals were included in the PRR-based signals as well as IC- or ROR-based ones, and PRR- and IC-based signals were included in ROR-based ones. The PRR scores of PRR-based signals were significantly larger for 15 of 16 drugs when adverse events were also detected as signals by the EBGM method, as were the IC scores of IC-based signals for all drugs; however, no such effect was observed in the ROR scores of ROR-based signals.

CONCLUSIONS

The EBGM method was the most conservative among the 4 methods examined, which suggested its better suitability for pharmacoepidemiological studies. Further examinations should be performed on the reproducibility of clinical observations, especially for EBGM-based signals.

Safety and effectiveness of ferumoxytol in hemodialysis patients at 3 dialysis chains in the United States over a 12-month period

BACKGROUND

Intravenous (IV) iron is the treatment of choice for iron-deficiency anemia (IDA) in patients with dialysis-dependent chronic kidney disease (DD-CKD). However, IV iron products have been associated with serious adverse events (SAEs), including anaphylactoid reactions. Ferumoxytol is an IV iron preparation that can be injected over a short period of time. Although randomized clinical trials support ferumoxytol's efficacy and safety, additional insights may be drawn from the acquisition of long-term, repeat dosing efficacy and safety data in a real-world setting.

OBJECTIVE

The goal of this study was to characterize the effectiveness and safety profile of ferumoxytol as administered to adult DD-CKD patients with IDA in a real-world setting. The ability of ferumoxytol to maintain hemoglobin (Hb), transferrin saturation (TSAT), and ferritin treatment targets established by the 2006 Kidney Disease Outcomes Quality Initiative guidelines was determined in 3 medium-sized US-based dialysis chains.

METHODS

This retrospective, observational study was conducted to examine laboratory and dosing data for all patients who received any dose of ferumoxytol at 3 US-based dialysis chains over a 12-month period. Investigators and/or physicians from each of the chains also made independent determinations regarding the seriousness of any adverse event (AE). Special attention was paid to the incidence and types of AEs and SAEs that were potentially associated with ferumoxytol.

RESULTS

Over the 12-month observation period, 8666 patients (mean [SD] age in chains A, B and C, 63.9 [14.8], 63.9 [14.9] and 63.6 [15.1], respectively), were treated with 33,358 doses of ferumoxytol across the 3 chains. Treatment with ferumoxytol corresponded to an increased mean monthly Hb level relative to baseline (0.13-0.69 g/dL) and led to an increase in the proportion of patients maintained within the target Hb range of 10 to 12 g/dL (61%-72%). Ferumoxytol was also associated with increases in TSAT and ferritin that stabilized throughout the observation period. Incidence of AEs was similar across the 3 chains; between 0.07% and 1.77% of all patients treated at each chain experienced an AE associated with ferumoxytol administration. SAEs were reported in 0.2% of patients. The most common AEs reported (≥6 patients) were nausea (0.37% of patients), pruritus (0.29%), vomiting (0.25%), hypotension (0.21%), and dyspnea (0.20%). Two patients (0.02%) experienced anaphylactoid reactions. The AE profile of ferumoxytol remained consistent with that reported from controlled clinical trials.

CONCLUSIONS

These long-term data, which include repeat dosing in a large number of DD-CKD patients with IDA in a real-world setting, confirm the effectiveness of ferumoxytol in increasing and maintaining Hb levels within the target range and with favorable assessments of long-term safety.

Data mining of the public version of the FDA Adverse Event Reporting System

The US Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS, formerly AERS) is a database that contains information on adverse event and medication error reports submitted to the FDA. Besides those from manufacturers, reports can be submitted from health care professionals and the public. The original system was started in 1969, but since the last major revision in 1997, reporting has markedly increased. Data mining algorithms have been developed for the quantitative detection of signals from such a large database, where a signal means a statistical association between a drug and an adverse event or a drug-associated adverse event, including the proportional reporting ratio (PRR), the reporting odds ratio (ROR), the information component (IC), and the empirical Bayes geometric mean (EBGM). A survey of our previous reports suggested that the ROR provided the highest number of signals, and the EBGM the lowest. Additionally, an analysis of warfarin-, aspirin- and clopidogrel-associated adverse events suggested that all EBGM-based signals were included in the PRR-based signals, and also in the IC- or ROR-based ones, and that the PRR- and IC-based signals were in the ROR-based ones. In this article, the latest information on this area is summarized for future pharmacoepidemiological studies and/or pharmacovigilance analyses.