Trends in rates of acetaminophen-related adverse events in the United States.

PURPOSE: The goal of this study is to summarize trends in rates of adverse events attributable to acetaminophen use, including hepatotoxicity and mortality. METHODS: A comprehensive analysis of data from three national surveillance systems estimated rates of acetaminophen-related events identified in different settings, including calls to poison centers (2008-2012), emergency department visits (2004-2012), and inpatient hospitalizations (1998-2011). Rates of acetaminophen-related events were calculated per setting, census population, and distributed drug units. RESULTS: Rates of poison center calls with acetaminophen-related exposures decreased from 49.5/1000 calls in 2009 to 43.5/1000 calls in 2012. Rates of emergency department visits for unintentional acetaminophen-related adverse events decreased from 58.0/1000 emergency department visits for adverse drug events in 2009 to 50.2/1000 emergency department visits in 2012. Rates of hospital inpatient discharges with acetaminophen-related poisoning decreased from 119.8/100 000 hospitalizations in 2009 to 108.6/100 000 hospitalizations in 2011. After 2009, population rates of acetaminophen-related events per 1 million census population decreased for poison center calls and hospitalizations, while emergency department visit rates remained stable. However, when accounting for drug sales, the rate of acetaminophen-related events (per 1 million distributed drug units) increased after 2009. Prior to 2009, the rates of acetaminophen-related hospitalizations had been slowly increasing (p-trend = 0.001). CONCLUSIONS: Acetaminophen-related adverse events continue to be a public health burden. Future studies with additional time points are necessary to confirm trends and determine whether recent risk mitigation efforts had a beneficial impact on acetaminophen-related adverse events. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Patient understanding of drug risks: an evaluation of medication guide assessments.

PURPOSE: When a Medication Guide (MG) is part of Risk Evaluation and Mitigation Strategy (REMS), manufacturers assess the effectiveness of MGs through patient surveys, which have not undergone systematic evaluation. We aimed to characterize knowledge rates from these patient surveys, describe their design and respondent characteristics, and explore predictors of acceptable knowledge rates. METHODS: We analyzed MG assessments submitted to the Food and Drug Administration from September 2008 through June 2012. We evaluated the prevalence of specific characteristics, and calculated knowledge rates, whereby we defined "acceptable knowledge" when ≥ 80% of respondents correctly answered questions about the primary drug risk. Univariate logistic models were used to investigate the predictors of acceptable knowledge rates. RESULTS: We analyzed the first completed MG assessment for each drug with a patient survey, resulting in 66 unique MG assessments. The mean knowledge rate was 63.8%, with 20 MG assessments (30.3%) achieving the 80% threshold. Compared to assessments that did not reach acceptable knowledge rates, those that did were more likely associated with additional REMS elements (e.g. Elements to Assure Safe Use or Communication Plans). Other factors, including mean age, reading or understanding the MG, and being offered or accepting counseling were not associated with knowledge rates. There was considerable variation in the design of MG assessments. CONCLUSIONS: Most MG assessments did not reach the 80% knowledge threshold, but those associated with additional interventions were more likely to achieve it. Our study highlights the need to improve patient-directed information and the methods of assessing it.

Candidate metrics for evaluating the impact of prescriber education on the safe use of extended-release/long-acting (ER/LA) opioid analgesics.

OBJECTIVE: The objective of this study was to develop metrics to assess opioid prescribing behavior as part of the evaluation of the Extended-Release/Long-Acting (ER/LA) Opioid Analgesic Risk Evaluation and Mitigation Strategies (REMS). DESIGN: Candidate metrics were selected using published guidelines, examined using sensitivity analyses, and applied to cross-sectional rolling cohorts of Medicare patients prescribed with extended-release oxycodone (ERO) between July 2, 2006 and July 1, 2011. Potential metrics included prescribing opioid-tolerant-only ER/LA opioid analgesics to non-opioid-tolerant patients, prescribing early fills to patients, and ordering drug screens. RESULTS: Proposed definitions for opioid tolerance were seven continuous days of opioid usage of at least 30 mg oxycodone equivalents, within the 7 days (primary) or 30 days (secondary) prior to first opioid-tolerant-only ERO prescription. Forty-four percent of opioid-tolerant-only ERO episodes met the primary opioid tolerance definition; 56% met the secondary definition. Fills were deemed "early" if a prescription was filled before 70% (primary) or 50% (secondary) of the prior prescription's days' supply was to be consumed. Five percent (primary) and 2% (secondary) of episodes had more than or equal to two early fills during treatment. At least one drug screen was billed in 14% of episodes. Stratified analyses indicated that older patients were less likely to be opioid tolerant at the time of the first opioid-tolerant-only ERO prescription. CONCLUSIONS: Investigators propose three metrics to monitor changes in prescribing behaviors for opioid analgesics that might be used to evaluate the ER/LA Opioid Analgesics REMS. Low frequencies of patients, particularly those >85 years, were likely to be opioid tolerant prior to receiving prescriptions for opioid-tolerant-only ERO.

Characterization of acetaminophen overdose-related emergency department visits and hospitalizations in the United States.

PURPOSE: To estimate the number of acetaminophen overdose-related emergency department (ED) visits and hospitalizations in the United States, characterize these by intentionality, age, and gender, and compare the strengths and limitations of the utilized databases. METHODS: We used data from the National Hospital Ambulatory Medical Care Survey (NHAMCS) and the National Electronic Injury Surveillance System (NEISS) to estimate the number of relevant ED visits in the United States between 2000 and 2007, and the National Hospital Discharge Survey (NHDS) to estimate the number of relevant hospitalizations in the United States between 1991 and 2006. National estimates and their standard errors were calculated using information provided in each database. We used the standard United States population in 2000 to calculate age-adjusted rates. RESULTS: We estimate an annual average of 44,348 (NHAMCS, 2000-2007) or 78,414 (NEISS, 2006-2007) acetaminophen overdose-related ED visits and 33,520 (NHDS, 2000-2006) hospitalizations. For 2000-2006 we calculated an age-adjusted rate of 13.9 acetaminophen overdose-related hospitalizations per 100,000 US population, with the highest rate (15.7) occurring from 2005 to 2006. Between 1991 and 2006, there was no decrease noted in hospitalizations for intentional or unintentional overdoses. The majority of overdoses reported in NEISS (69.8%) and NHDS (74.2%) were classified as intentional (suicides or suicidal gestures), whereas in NHAMCS, intentionality was evenly distributed. CONCLUSIONS: Our results suggest that acetaminophen overdose, both intentional and unintentional, remains a significant public health concern. With an understanding of their methodological characteristics and limitations, these national databases can be useful tools to characterize acetaminophen overdose-related ED visits and hospitalizations.

Prevalence of osteonecrosis of the jaw in patients with oral bisphosphonate exposure.

PURPOSE: Osteonecrosis of the jaw (ONJ) is a serious complication associated with bisphosphonate therapy, but its epidemiology in the setting of oral bisphosphonate therapy is poorly understood. The present study examined the prevalence of ONJ in patients receiving chronic oral bisphosphonate therapy. MATERIALS AND METHODS: We mailed a survey to 13,946 members who had received chronic oral bisphosphonate therapy as of 2006 within a large integrated health care delivery system in Northern California. Respondents who reported ONJ, exposed bone or gingival sores, moderate periodontal disease, persistent symptoms, or complications after dental procedures were invited for examination or to have their dental records reviewed. ONJ was defined as exposed bone (of >8 weeks' duration) in the maxillofacial region in the absence of previous radiotherapy. RESULTS: Of the 8,572 survey respondents (71 +/- 9 years, 93% women), 2,159 (25%) reported pertinent dental symptoms. Of these 2,159 patients, 1,005 were examined and an additional 536 provided dental records. Nine ONJ cases were identified, representing a prevalence of 0.10% (95% confidence interval 0.05% to 0.20%) among the survey respondents. Of the 9 cases, 5 had occurred spontaneously (3 in palatal tori) and 4 occurred in previous extraction sites. An additional 3 patients had mandibular osteomyelitis (2 after extraction and 1 with implant failure) but without exposed bone. Finally, 7 other patients had bone exposure that did not fulfill the criteria for ONJ. CONCLUSIONS: ONJ occurred in 1 of 952 survey respondents with oral bisphosphonate exposure (minimum prevalence of 1 in 1,537 of the entire mailed cohort). A similar number had select features concerning for ONJ that did not meet the criteria. The results of the present study provide important data on the spectrum of jaw complications among patients with oral bisphosphonate exposure.

Emergency department visits attributed to selected analgesics, United States, 2004-2005.

PURPOSE: To estimate the rate of emergency department (ED) visits attributed to selected analgesic-containing medications. METHODS: We used a nationally representative public health surveillance system to provide estimates of adverse events identified in EDs, and a national telephone survey to provide estimates of selected analgesic-containing medication usage in the US population, 2004-2005. Analysis was restricted to products containing acetaminophen, aspirin, ibuprofen, or naproxen. Types of adverse events and outcomes were compared. Estimated numbers and rates of ED visits were calculated by analgesic groupings and patient age groups. RESULTS: The estimated overall rate of ED visits attributed to analgesic-containing medications was 1.6 visits /100,000 users per week. The very old and very young had the highest rates; there were minimal differences in rates by patient gender. Acetaminophen was the attributed drug with the most estimated ED visits and generally had the highest rates of ED visits. The highest estimated rate for a specific product group was among subjects 18-64 years of age taking narcotic-acetaminophen products (8.9 ED visits /100,000 users per week). Overall, 12% of patients presenting to EDs with analgesic-attributed events were hospitalized. CONCLUSIONS: Rates of ED visits due to analgesics vary depending on the age of the patient and the product; most do not result in hospitalization. Although the rate of emergency visits is relatively low, because of the wide use of the analgesics, public health impact is considerable.

Antidepressant medication use and risk of persistent pulmonary hypertension of the newborn.

PURPOSE: To determine the prevalence of persistent pulmonary hypertension of the newborn (PPHN) among infants whose mothers were exposed to antidepressants in the third trimester of pregnancy compared to the prevalence among infants whose mothers were not exposed to antidepressants in the third trimester. METHODS: A retrospective study was conducted using the automated databases of four health plans participating in the HMO Research Network Center for Education and Research on Therapeutics. Women who delivered an infant in a hospital from 1 January 1996 through 31 December 2000 were identified. The administrative databases were used to identify full-term infants whose mothers received an antidepressant during the third trimester of pregnancy and unexposed infants whose mothers did not receive an antidepressant during the third trimester. Hospitalization data were used to identify diagnoses or procedure codes potentially indicative of PPHN. RESULTS: Among 1104 infants exposed to antidepressants in the third trimester and a matched sample of 1104 unexposed infants, five infants were classified by the expert reviewers as having PPHN. Among those infants whose mothers were exposed to selective serotonin reuptake inhibitors (SSRIs) in the third trimester, the prevalence of PPHN was 2.14 per 1000 (95% confidence interval (CI) 0.26, 7.74), while the prevalence among infants whose mothers were not exposed was 2.72 per 1000 (95%CI 0.56, 7.93). CONCLUSIONS: We did not find an association between SSRI use in late pregnancy and PPHN. Limitations of the present study, including the small number of confirmed cases, suggest further research in this area may be warranted.

Use of antidepressant medications during pregnancy: a multisite study.

OBJECTIVE: This study was undertaken to provide information on the prevalence of use of antidepressant drugs among pregnant women in the United States. STUDY DESIGN: A retrospective study was conducted using the automated databases of 7 health plans. Women who delivered an infant in a hospital were identified. Antidepressant drug use was evaluated assuming a gestational duration of 270 days. RESULTS: Among the 118,935 deliveries occurring from 2001-2005, 6.6% of women were dispensed an antidepressant during pregnancy. Antidepressant drug use increased from 2.0% in 1996 to 7.6% of deliveries in 2004 and 2005. Selective serotonin reuptake inhibitor use increased from 1.5% in 1996 to 6.4% in 2004 and 6.2% in 2005. CONCLUSION: Our finding that nearly 8% of pregnant women were prescribed antidepressants drugs during the years 2004 and 2005 highlights the importance of understanding the effects of these medications on the developing fetus and on the pregnant woman.

Drug-risk communication to pharmacists: assessing the impact of risk-minimization strategies on the practice of pharmacy.

OBJECTIVES: To gain insight on the knowledge, opinions, barriers, and practices of pharmacists regarding drug risk-minimization tools. DESIGN: Descriptive, nonexperimental, cross-sectional survey. SETTING: 20 states in the United States, fall 2004. PARTICIPANTS: 2,052 randomly selected licensed pharmacists employed in a position requiring an active pharmacist license at the time of the survey and who responded to the survey. INTERVENTION: Participants completed a four-page survey regarding their experience with different types of risk-minimization tools. MAIN OUTCOME MEASURE: Univariate distributions for each question were analyzed. RESULTS: 50% of survey recipients responded to the mailing; 88% of respondents had an active pharmacist license. Of respondents, 18% reported never having received a Dear Healthcare Professional letter and 29% stated that they were not familiar with Medication Guides. Patient package inserts were thought to be somewhat effective by 53% of respondents. Of pharmacists who dispensed a drug with programs for special stickers to be affixed on prescriptions to indicate that the labeled risk had been addressed by the prescriber, 41% reported receiving a prescription without a sticker; 45% dispensed the prescription when stickers were missing. Sixty percent of pharmacists stated that risk-minimization programs have a negative impact on the daily practice of pharmacy; nevertheless, many acknowledged that it was a necessary duty. CONCLUSION: Pharmacists might benefit from additional training on risk-minimization strategies. The successful implementation and impact of risk-minimization programs on the practice of pharmacy should be carefully considered by drug manufacturers and regulators.

Increasing use of antidepressants in pregnancy.

OBJECTIVE: The purpose of this study was to quantify the rate of exposures to antidepressants during pregnancy in a large cohort of women. STUDY DESIGN: This was a retrospective cohort study of 105,335 pregnancies among women enrolled in Tennessee Medicaid from 1999-2003. Pregnancies were classified according to antidepressant exposures during pregnancy using previously validated computerized pharmacy records linked with birth certificates. RESULTS: During the study period, 8.7% of women giving birth had exposure to any antidepressant; 6.2% had exposure to a selective serotonin reuptake inhibitor. Maternal age > 25 years (P < .0001), white race (P < .0001), and education > 12 years (P = .008) were significant predictors of antidepressant exposure. The proportion of pregnancies with antidepressant use increased from 5.7% of pregnancies in 1999 to 13.4% of pregnancies in 2003 (p < .0001). The increase was mostly accounted for by increases in selective serotonin reuptake inhibitor exposures. CONCLUSION: There is an urgent need for further studies that better quantify the fetal consequences of exposure to antidepressants.

Suicidal adverse events in pediatric randomized, controlled clinical trials of antidepressant drugs are associated with active drug treatment: a meta-analysis.

OBJECTIVE: The aim of this study was to compare the incidence of suicidal ideation and behaviors observed with antidepressant drug treatment to the incidence with placebo, in randomized, controlled pediatric clinical trials. METHODS: Manufacturers of nine antidepressant drugs identified suicidal adverse events in randomized, placebo-controlled, pediatric clinical trials that they had sponsored. Events were found with an electronic search for adverse event descriptions, including key words suggesting suicidal ideation or self-injury, along with a manual review of all adverse events meeting the standard regulatory definition for seriousness. Incidence rate data for these events supplied by the manufacturers were combined across trials to yield Mantel-Haenszel combined risk estimates. RESULTS: Data from 22 randomized, short-term, placebo-controlled, pediatric trials in various indications, involving nine different antidepressant drugs, were available for analysis. A total of 2298 pediatric subjects were exposed to active drug, and 1952 to placebo. Seventy eight (78) serious suicidal adverse events occurred in these trials (54 with active drug and 24 with placebo); there were no completed suicides. The combined incidence rate ratio across all trials for serious suicidal adverse events was 1.89 (95% Confidence Interval, 1.18-3.04). CONCLUSIONS: In short-term, placebo-controlled, pediatric studies of antidepressants, active drug treatment was associated with a rate of serious suicidal events almost twice that of placebo.

A study of compliance with FDA recommendations for pemoline (Cylert).

OBJECTIVE: To assess compliance with product labeling recommendations to use pemoline as second-line therapy for attention-deficit/hyperactivity disorder (ADHD) and to obtain baseline and biweekly liver enzyme tests. METHOD: Retrospective cohort study using administrative claims data to identify first-line therapies and liver enzyme tests among pemoline users between January 1, 1998, and March 31, 2000. Prescriptions for first-line therapy were searched for 90 days prior to the first pemoline claim. Liver enzyme testing (baseline and follow-up) was compared between two groups (the prerecommendation cohort October 1,1998, to March 31, 1999, and the postrecommendation cohort October 1,1999, to March 31,2000). RESULTS: 1,308 patients received at least one pemoline prescription during the study period; 76% of patients < or = 20 years were male. ADHD was the claims-identified indication for 688 patients (52%). Despite the labeling recommendation for use as second-line therapy, only 237 ADHD patients (34%) received a first-line therapy prior to pemoline. Only 12% and 11% of the pre- and post-cohort patients, respectively, received baseline liver enzyme tests; 9% in the pre- and 12% in the post-cohort received at least one liver enzyme follow-up test. CONCLUSIONS: Compliance with product labeling was low for both recommendations. Understanding the reasons for this finding could help improve risk management strategies.

Surveillance of medical device-related hazards and adverse events in hospitalized patients.

CONTEXT: Although adverse drug events have been extensively evaluated by computer-based surveillance, medical device errors have no comparable surveillance techniques. OBJECTIVES: To determine whether computer-based surveillance can reliably identify medical device-related hazards (no known harm to patient) and adverse medical device events (AMDEs; patient experienced harm) and to compare alternative methods of detection of device-related problems. DESIGN, SETTING, AND PARTICIPANTS: This descriptive study was conducted from January through September 2000 at a 520-bed tertiary teaching institution in the United States with experience in using computer tools to detect and prevent adverse drug events. All 20 441 regular and short-stay patients (excluding obstetric and newborn patients) were included. MAIN OUTCOME MEASURES: Medical device events as detected by computer-based flags, telemetry problem checklists, International Classification of Diseases, Ninth Revision (ICD-9) discharge code (which could include AMDEs present at admission), clinical engineering work logs, and patient survey results were compared with each other and with routine voluntary incident reports to determine frequencies, proportions, positive predictive values, and incidence rates by each technique. RESULTS: Of the 7059 flags triggered, 552 (7.8%) indicate a device-related hazard or AMDE. The estimated 9-month incidence rates (number per 1000 admissions [95% confidence intervals]) for AMDEs were 1.6 (0.9-2.5) for incident reports, 27.7 (24.9-30.7) for computer flags, and 64.6 (60.4-69.1) for ICD-9 discharge codes. Few of these events were detected by more than 1 surveillance method, giving an overall incidence of AMDE detected by at least 1 of these methods of 83.7 per 1000 (95% confidence interval, 78.8-88.6) admissions. The positive predictive value of computer flags for detecting device-related hazards and AMDEs ranged from 0% to 38%. CONCLUSIONS: More intensive surveillance methods yielded higher rates of medical device problems than found with traditional voluntary reporting, with little overlap between methods. Several detection methods had low efficiency in detecting AMDEs. The high rate of AMDEs suggests that AMDEs are an important patient safety issue, but additional research is necessary to identify optimal AMDE detection strategies.

Informatic tools and approaches in postmarketing pharmacovigilance used by FDA.

The safety profile of newly approved drugs and therapeutic biologics is less well developed by pre-marketing clinical testing than is the efficacy profile. The full safety profile of an approved product is established during years of clinical use. For nearly 40 years, the FDA has relied on the voluntary reporting of adverse events by healthcare practitioners and patients to help establish the safety of marketed products. Epidemiologic studies, including case series, secular trends, case-control and cohort studies, are used to supplement the investigation of a safety signal. Ideally, active surveillance systems would supplement the identification and exploration of safety signals. The FDA has implemented a number of initiatives to help identify safety problems with drugs and continues to evaluate their efforts.

Estimates of acetaminophen (Paracetomal)-associated overdoses in the United States.

OBJECTIVE: To estimate the number of acetaminophen-associated overdoses in the United States and identify possible risk factors for intervention. METHODS: The investigators obtained estimates of acetaminophen-associated overdoses using different national databases. Two emergency room databases, a hospital discharge database, a national mortality file, and a poison surveillance database were used to identify cases. The FDA's spontaneous reporting system was searched to identify possible root causes for overdoses. RESULTS: Analysis of national databases show that acetaminophen-associated overdoses account for about 56,000 emergency room visits and 26,000 hospitalizations yearly. Analysis of national mortality files shows 458 deaths occur each year from acetaminophen-associated overdoses; 100 of these are unintentional. The poison surveillance database showed near-doubling in the number of fatalities associated with acetaminophen from 98 in 1997 to 173 in 2001. AERS data describe a number of possible causes for unintentional acetaminophen-associated overdoses. CONCLUSIONS: Each year a substantial numbers of Americans experience intentional and unintentional acetaminophen-associated overdoses that, in severe cases, lead to serious illness and possible death. This summary of a series of analyses highlights the need for strategies to reduce this public health burden.

What is prescription labeling communicating to doctors about hepatotoxic drugs? A study of FDA approved product labeling.

PURPOSE: The objective of this study was to evaluate the informativeness and consistency of product labeling of hepatotoxic drugs marketed in the United States. METHODS: We searched the Physicians' Desk Reference-2000 for prescription drugs with hepatic failure and/or hepatic necrosis listed in the labeling. We used a six-item checklist to evaluate the 'informativeness' and consistency of the labeling content. An informativeness score equaled the proportion of checklist items present in each drug's labeling. RESULTS: Ninety-five prescription drugs were included in the study. Eleven (12%) of the drugs had information related to hepatic failure in a Black Boxed Warning, 52 (54%) in the Warnings section and 32 (34%) in the Adverse Reactions section of the label. The mean informativeness score was 35%; the score was significantly higher, 61%, when the risk was perceived to be high. The informativeness of labeling was not affected by the time of the labeling, but differed across the Center for Drug Evaluation and Research (CDER) Review Division responsible for the labeling. CONCLUSIONS: The information provided in labeling is variable and affected by many factors, including the perceived level of risk and review division strategy. Product labeling may benefit from current FDA initiatives to improve the consistency of risk-related labeling.