Fifty years of paracetamol (acetaminophen) poisoning: the development of risk assessment and treatment 1973-2023 with particular focus on contributions published from Edinburgh and Denver.

INTRODUCTION: Fifty years ago, basic scientific studies and the availability of assay methods made the assessment of risk in paracetamol (acetaminophen) poisoning possible. The use of the antidote acetylcysteine linked to new methods of risk assessment transformed the treatment of this poisoning. This review will describe the way in which risk assessment and treatments have developed over the last 50 years and highlight the remaining areas of uncertainty. METHODS: A search of PubMed and its subsidiary databases revealed 1,166 references published in the period 1963-2023 using the combined terms "paracetamol", "poisoning", and "acetylcysteine". Focused searches then identified 170 papers dealing with risk assessment of paracetamol poisoning, 141 with adverse reactions to acetylcysteine and 114 describing different acetylcysteine regimens. To manage the extensive literature, we focused mainly on contributions made by the authors during their time in Edinburgh and Denver. DOSE AND CONCENTRATION RESPONSE: The key relationship between paracetamol dose and toxicity risk was established in 1971 and led to the development of the Rumack-Matthew nomogram from data collected in Edinburgh. MECHANISMS OF TOXICITY: A series of papers on the mechanisms of toxicity were published in 1973, and these showed that paracetamol hepatotoxicity was caused by the formation of a toxic intermediate epoxide metabolite normally detoxified by glutathione but which, in excess, was bound covalently to hepatic enzymes and proteins. An understanding of the relationship between the rate of paracetamol metabolism, paracetamol concentration, and toxic hazard in humans soon followed. ANTIDOTE DEVELOPMENT AND EFFICACY IN PATIENTS: These discoveries were followed by the testing of a range of sulfhydryl-donors in animals and "at risk" patients. Acetylcysteine was developed as the lead intravenous antidote in the United Kingdom. The license holder in the United States refused to make an intravenous formulation. Thus, oral acetylcysteine became the antidote trialed in the United States National Multicenter Study. Intravenous acetylcysteine regimens used initially in the United Kingdom and subsequently in the United States used loading doses of 150 mg/kg over 15 minutes or one hour, 50 mg/kg over four hours, and 100 mg/kg over 16 hours. These regimens were associated with adverse drug reactions (nausea, vomiting and anaphylactoid reactions) and hence, treatment interruption. Newer dosing regimens now give loading doses more slowly. One, the Scottish and Newcastle Anti-emetic Pretreatment protocol, using an acetylcysteine regimen of 100 mg/kg over two hours followed by 200 mg/kg over 10 hours, has been widely adopted in the United Kingdom. A cohort comparison study suggests this regimen has comparable efficacy to standard regimens and offers opportunities for selective higher acetylcysteine dosing. RISK ASSESSMENT AT PRESENTATION: No dose-ranging studies with acetylcysteine were done, and no placebo-controlled studies were performed. Thus, there is uncertainty regarding the optimal dose of acetylcysteine, particularly in patients ingesting very large overdoses of paracetamol. The choice of intervention concentration on the Rumack-Matthew nomogram has important consequences for the proportion of patients treated. The United States National Multicenter Study used a "treatment" line starting at 150 mg/L (992 µmol/L) at 4 hours post overdose, extending to 24 hours with a half-life of 4 hours, now standard there, and subsequently adopted in Australia and New Zealand. In the United Kingdom, the treatment line was initially 200 mg/L (1,323 µmol/L) at 4 hours (the Rumack-Matthew "risk" line). In 2012, the United Kingdom Medicines and Healthcare products Regulatory Agency lowered the treatment line to 100 mg/L (662 µmol/L) at 4 hours for all patients, increasing the number of patients admitted and treated at a high cost. Risk assessment is a key issue for ongoing study, particularly following the development of potential new antidotes that may act in those at greatest risk. The development of biomarkers to assess risk is ongoing but has yet to reach clinical trials. CONCLUSION: Even after 50 years, there are still areas of uncertainty. These include appropriate acetylcysteine doses in patients who ingest different paracetamol doses or multiple (staggered) ingestions, early identification of at-risk patients, and optimal treatment of late presenters.

Drug product dispensing and estimates of use in a general population survey as a signal detection problem.

PURPOSE: Understanding potential bias due to rarity of the outcome is important when monitoring newly approved drugs and drugs with low availability to the general public. Although there is an increasing use of online surveys to investigate health outcomes, the limits of inference due to drug availability have not been studied. The goal of this study was to quantify the relationship between dispensing of prescription drugs and estimates of use in an online general population survey. METHODS: An online repeated, cross-sectional survey from 2018 to 2020 was used to estimate the number of adults in the United States who used prescription drugs in the general population and compared to estimated number of prescriptions dispensed over an equivalent time period. Joinpoint regression was used to quantify thresholds. A sample of respondents was retested to estimate reliability statistics. RESULTS: A model with a single threshold was the best fit, with the estimated threshold of 565 000 (95% CI: 9500-11 600 000) prescriptions dispensed per year. Above the threshold, there was a significant association between dispensing and estimates (p < 0.001); below the threshold, the relationship was not significant (p = 0.912). Above the threshold, responses were more reliable than random chance, and reliability steadily increased with increased dispensing. CONCLUSIONS: These results suggest the threshold demarcates two distinct pharmacoepidemiological paradigms when investigating drug use in general population surveys. Dispensing can be used as a guide to determine the epidemiological paradigm that is best suited.

Real-world misuse, abuse, and dependence of abuse-deterrent versus non-abuse-deterrent extended-release morphine in Medicaid non-cancer patients.

OBJECTIVE: Opioids with abuse-deterrent properties may reduce widespread abuse, misuse, and diversion of these products. This study aimed to quantify misuse, abuse, dependence, and health resource use of extended-release morphine sulfate with sequestered naltrexone hydrochloride (ER-MSN; EMBEDA®), compared with non-abuse-deterrent extended-release morphine (ERM) products in Medicaid non-cancer patients. METHODS: Administrative medical and pharmacy claims data were analyzed for 10 Medicaid states from 1 January 2015, to 30 June 2016. Patients were included if they received a prescription for ER-MSN or any oral, non-abuse-deterrent ERM. Index date was the date of first prescription for an ER-MSN or ERM. Abuse/dependence, non-fatal overdose, emergency department (ED) visits, and ED/inpatient readmissions were determined for each participant. An overall measure of misuse and abuse was also calculated. To account for differences in follow-up, all counts are expressed per 100 patient-years. RESULTS: There were 4,857 patients who received ER-MSN and 10,357 who received an ERM. The average age in the two cohorts was approximately 45 years old. From pre-index to follow-up, the number of patients per 100 patient-years with a diagnosis code indicating abuse or dependence increased by 0.91 (95% confidence interval [CI]: 0.85, 0.97) in the ER-MSN cohort and 2.23 (95% CI: 2.14, 2.32) in the ERM cohort. The number of patients per 100 patient-years with an opioid-related non-fatal overdose increased by 0.05 (95% CI: 0.04, 0.06) in the ER-MSN cohort compared with 0.11 (95% CI: 0.09, 0.13) in the ERM cohort. The opioid abuse overall composite score increased by 1.36 (95% CI: 1.24, 1.48) in the post-index period in the ER-MSN cohort compared to 3.21 (95% CI: 3.10, 3.32) in the ERM cohort. CONCLUSION: Misuse, abuse, and dependence events were numerically lower in patients receiving ER-MSN compared with those receiving ERM products.

Scoring the best deal: Quantity discounts and street price variation of diverted oxycodone and oxymorphone.

PURPOSE: Diverted prescription opioids are significant contributors to drug overdose mortality. Street price has been suggested as an economic metric of the diverted prescription opioid black market. This study examined variables that may influence the street price of diverted oxycodone and oxymorphone. METHODS: A cross-sectional study was conducted utilizing data from the previously validated, crowdsourcing website StreetRx. Street price reports of selected oxycodone and oxymorphone products, between August 22, 2014 and June 30, 2016, were considered for analysis. Geometric means and 95% confidence intervals were calculated comparing prices per milligram of drug in US dollars. Univariate and multivariable regressions were used to examine the influence of dosage strength, drug formulation, and bulk purchasing on street price. RESULTS: A total of 5611 oxycodone and 1420 oxymorphone reports were analyzed. Across various dosages and formulations, geometric mean prices per milligram ranged between $0.12 and $1.07 for oxycodone and $0.73 and $2.90 for oxymorphone. For a 2-fold increase in dosage strength, there is a 24.0% (95% CI: -28.1%, -19.6%, P < 0.001) and a 22.5% (95% CI: -24.2%, -20.8%, P < 0.001) decrease on average in price per milligram for oxycodone and oxymorphone, respectively. Lower potency, high dosage strength, crush-resistant opioids, and those purchased in bulk were significantly cheaper. CONCLUSION: Street prices for diverted oxycodone and oxymorphone are influenced by multiple factors including potency, dosage, formulation, and bulk purchasing. Buyers who purchase large quantities of low potency, large dosage, crush-resistant formulation prescription opioids can expect to achieve the lowest price.

Medication history assessment in research: A randomized controlled trial comparing tablet-based (eMedHAT) versus structured interview (MedHAT).

PURPOSE: Accurate capture of medication use is important for high quality research. For epidemiologic studies, medication histories are the most common measure of exposure when trying to identify associations between medications and outcomes. Concomitant medications can alter the efficacy or safety of study drugs in clinical trials. However, there are few studies evaluating the accuracy and efficiency of methods to collect these histories. The objective of this study is to compare the accuracy of medication histories collected by structured interview to histories captured using a tablet-based application. METHODS: This was a randomized controlled trial. Subjects were instructed to record all prescription medications, non-prescription medications, vitamins, and dietary supplements in a diary for 30 days. At the end of the diary collection, subjects were randomized to providing a medication history during a structured interview by a trained research assistant (MedHAT) or using a tablet-based application (eMedHAT). The accuracy of these histories was compared using an adjusted analysis. We also measured the duration of the history collection and data entry. RESULTS: A total of 111 subjects were in the MedHAT group and 109 subjects were in the eMedHAT group. Recall of medications for the 30-day period was similar for MedHAT and eMedHAT (76.9% versus 75.2%, respectively). The total time required for researchers and subjects for history collection and data entry was 16 minutes shorter for the tablet-based method. CONCLUSIONS: Tablet-based medication histories were as accurate as histories obtained by research assistants and required less time for the researcher.

Assessment of Tapentadol API Abuse Liability With the Researched Abuse, Diversion and Addiction-Related Surveillance System.

Tapentadol, a Schedule II opioid with a combination of µ-opioid activity and norepinephrine reuptake inhibition, is used for the management of moderate to severe acute and chronic pain. Its dual mechanism of action is thought to reduce opioid-related side effects that can complicate pain management. Since approval, tapentadol has been tracked across multiple outcomes suggesting abuse liability, and a pattern of relatively low, although not absent, abuse liability has been found. This retrospective cohort study further details the abuse liability of tapentadol as an active pharmaceutical ingredient (API) when immediate-release as well as extended-release formulations were on the market together (fourth quarter of 2011 to second quarter of 2016). Tapentadol (API) was compared with tramadol, hydrocodone, morphine, oxycodone, hydromorphone, and oxymorphone across Poison Center, Drug Diversion, and Treatment Center Programs Combined data streams from the Researched Abuse, Diversion and Addiction-Related Surveillance system. Findings suggest the public health burden related to tapentadol to date is low, but present. Event rates of abuse per population-level denominators were significantly lower than all other opioids examined. However, when adjusted for drug availability, event rates of abuse were lower than most Schedule II opioids studied, but were not the lowest. Disentangling these 2 sets of findings further by examining various opioid formulations, such as extended-release and the role of abuse-deterrent formulations, is warranted. PERSPECTIVE: This article presents the results from an examination of tapentadol API across the Researched Abuse, Diversion and Addiction-Related Surveillance System: a broad and carefully designed postmarketing mosaic. Data to date from Poison Center, Drug Diversion, and Treatment Centers combined suggest a low, but present public health burden related to tapentadol.

Sustained reduction of diversion and abuse after introduction of an abuse deterrent formulation of extended release oxycodone.

BACKGROUND: The development of abuse deterrent formulations is one strategy for reducing prescription opioid misuse and abuse. A putative abuse deterrent formulation of oxycodone extended release (OxyContin®) was introduced in 2010. Early reports demonstrated reduced abuse and diversion, however, an analysis of social media found 32 feasible methods to circumvent the abuse deterrent mechanism. We measured trends of diversion, abuse and street price of OxyContin to assess the durability of the initial reduction in abuse. METHODS: Data from the Poison Center Program, Drug Diversion Program, Opioid Treatment Program, Survey of Key Informant Patients Program and StreetRx program of the Researched Abuse, Diversion, and Addiction-Related Surveillance (RADARS®) System were used. The average quarterly rates of abuse and diversion for OxyContin were compared from before reformulation to the rate in second quarter 2015. Rates were adjusted for population using US Census data and drug availability. RESULTS: OxyContin abuse and diversion declined significantly each quarter after reformulation and persisted for 5 years. The rate of abuse of other opioid analgesics increased initially and then decreased, but to lesser extent than OxyContin. Abuse through both oral and non-oral routes of self-administration declined following the reformulation. The geometric mean difference in the street price of reformulated OxyContin was 36% lower than the reformulated product in the year after reformulation. DISCUSSION: Despite methods to circumvent the abuse deterrent mechanism, abuse and diversion of OxyContin decreased promptly following the introduction of a crush- and solubility- resistant formulation and continued to decrease over the subsequent 5 years.

Accuracy of the Structured Medication History Assessment Tool (MedHAT) Compared with Recorded Real-Time Medication Use.

STUDY OBJECTIVE: Medication histories are collected to measure drug exposure in epidemiologic studies, to identify adverse drug events and in clinical practice. The objective of this study was to compare the accuracy of a structured medication history obtained by using the Medication History Assessment Tool (MedHAT) with a medication diary in which subjects recorded real-time medication use. DESIGN: Prospective observational study. SETTING: Outpatient research center. SUBJECTS: Sixty-seven adult healthy volunteers. INTERVENTIONS: Subjects were provided diaries to record the product name, dose quantity, and time that they used a prescription or nonprescription medication, supplement, or vitamin. After a minimum of 30 continuous days of diary use, a final interview was conducted, and medication history data were collected by using the MedHAT. MEASUREMENTS AND MAIN RESULTS: We compared the medications reported during the interview with the medications recorded in the diary for each day to determine the accuracy of the verbal history. The primary outcome was the proportion of matches for each day for each subject. Overall accuracy for medication use for the day preceding the interview was 90%, and accuracy during the 30 days preceding the interview was 76%. Recall was higher for subjects taking prescription medications, those who had more recent medication use, older subjects, and subjects taking a higher proportion of prescription medications. CONCLUSION: The MedHAT system provided relatively high accuracy for immediate past use and for prescription medications and may offer better accuracy than other methods. Medication histories are often inaccurate, however, and may represent an important source of misclassification in epidemiologic studies. Thus medication histories alone should be used cautiously when measuring associations between drug exposure and health outcomes.

Trends in opioid analgesic abuse and mortality in the United States.

BACKGROUND: The use of prescription opioid medications has increased greatly in the United States during the past two decades; in 2010, there were 16,651 opioid-related deaths. In response, hundreds of federal, state, and local interventions have been implemented. We describe trends in the diversion and abuse of prescription opioid analgesics using data through 2013. METHODS: We used five programs from the Researched Abuse, Diversion, and Addiction-Related Surveillance (RADARS) System to describe trends between 2002 and 2013 in the diversion and abuse of all products and formulations of six prescription opioid analgesics: oxycodone, hydrocodone, hydromorphone, fentanyl, morphine, and tramadol. The programs gather data from drug-diversion investigators, poison centers, substance-abuse treatment centers, and college students. RESULTS: Prescriptions for opioid analgesics increased substantially from 2002 through 2010 in the United States but then decreased slightly from 2011 through 2013. In general, RADARS System programs reported large increases in the rates of opioid diversion and abuse from 2002 to 2010, but then the rates flattened or decreased from 2011 through 2013. The rate of opioid-related deaths rose and fell in a similar pattern. Reported nonmedical use did not change significantly among college students. CONCLUSIONS: Postmarketing surveillance indicates that the diversion and abuse of prescription opioid medications increased between 2002 and 2010 and plateaued or decreased between 2011 and 2013. These findings suggest that the United States may be making progress in controlling the abuse of opioid analgesics. (Funded by the Denver Health and Hospital Authority.).

Poisoning in the United States: 2012 emergency medicine report of the National Poison Data System.

Deaths from drug overdose have become the leading cause of injury death in the United States, where the poison center system is available to provide real-time advice and collect data about a variety of poisonings. In 2012, emergency medical providers were confronted with new poisonings, such as bath salts (substituted cathinones) and Spice (synthetic cannabinoid drugs), as well as continued trends in established poisonings such as from prescription opioids. This article addresses current trends in opioid poisonings; new substances implicated in poisoning cases, including unit-dose laundry detergents, bath salts, Spice, and energy drinks; and the role of poison centers in public health emergencies such as the Fukushima radiation incident.

Assessment of prescription opioid intentional exposures across the rural-urban continuum in the United States using both population and drug availability rates.

PURPOSE: Prescription opioid abuse and misuse are a serious problem in the U.S. today. Several studies have shown that the epidemic disproportionately affects rural areas. This paper uses three different rates to gain a more complete picture of opioid abuse in rural areas. METHODS: This study examines prescription opioid intentional exposures using opioid classes tracked in the RADARS(®) System Poison Center Program. Intentional exposure rates were calculated adjusting for population and unique recipients of dispensed drug (URDD). These rates were analyzed using time (quarter) and the proportion of a three-digit zip code residing in a rural area as covariates. Additionally, the URDD per population rate was calculated to examine the proportion of the population filling prescriptions for opioids. RESULTS: After adjusting for population, intentional exposure cases significantly increased as the proportion of the population residing in a rural area increased. However, when adjusting for URDD, intentional exposure cases decreased with increasing rural population. The URDD per population increased as the proportion of people residing in a rural area increased. CONCLUSIONS: Using both population and URDD adjusted intentional exposure rates gives a more complete picture of opioid abuse in rural areas. Considering product availability can be used to develop opioid abuse prevention strategies and further the education of physicians serving rural areas about this epidemic.

Reductions in prescription opioid diversion following recent legislative interventions in Florida.

PURPOSE: Florida has been at the center of the nation's ongoing prescription opioid epidemic, with largely unregulated pain clinics and lax prescribing oversight cited as significant contributors to the opioid problem in the state. METHODS: In an effort to mitigate prescription opioid abuse and diversion in Florida, legislative interventions were implemented during 2010 and 2011, which included two primary elements: (i) comprehensive legislation to better regulate the operation of pain clinics; and (ii) a statewide prescription drug monitoring program to promote safer prescribing practices. Using systematic longitudinal data collected on a quarterly basis from law enforcement agencies across Florida, this report examined changes in prescription opioid diversion rates following implementation of these regulatory initiatives. Quarterly diversion rates for buprenorphine, fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone, and tramadol were calculated, and subsequently, hierarchical linear models were fit to test for differences in diversion rates over the 15 quarter period of interest. RESULTS: Significant declines in diversion rates were observed for oxycodone, methadone, and morphine; hydrocodone displayed a marginally significant decline. CONCLUSIONS: This study documented reductions in statewide opioid diversion rates following implementation of Florida's pain clinic and prescription drug monitoring program legislative interventions. Although these initial findings appear promising, continued surveillance of diversion is clearly warranted.

Toxicity from repeated doses of acetaminophen in children: assessment of causality and dose in reported cases.

Liver injury has been reported in children treated with repeated doses of acetaminophen. The objective of this study was to identify and validate reports of liver injury or death in children younger than 6 years who were administered repeated therapeutic doses of acetaminophen. We reviewed US Poison Center data, peer-reviewed literature, US Food and Drug Administration Adverse Event Reports, and US Manufacturer Safety Reports describing adverse effects after acetaminophen administration. Reports that described hepatic abnormalities (description of liver injury or abnormal laboratory testing) or death after acetaminophen administration to children younger than 6 years were included. The identified reports were double abstracted and then reviewed by an expert panel to determine if the hepatic injury was related to acetaminophen and whether the dose of acetaminophen was therapeutic (≤75 mg/kg) or supratherapeutic. Our search yielded 2531 reports of adverse events associated with acetaminophen use. From these cases, we identified 76 cases of hepatic injury and 26 deaths associated with repeated acetaminophen administration. There were 6 cases of hepatic abnormalities and no deaths associated with what our panel determined to be therapeutic doses. A large proportion of cases could not be fully evaluated due to incomplete case reporting. Although we identified numerous examples of liver injury and death after repeated doses of acetaminophen, all the deaths and all but 6 cases of hepatic abnormalities involved doses more than 75 mg/kg per day. This study suggests that the doses of less than 75 mg/kg per day of acetaminophen are safe for children younger than 6 years.

Crowdsourcing black market prices for prescription opioids.

BACKGROUND: Prescription opioid diversion and abuse are major public health issues in the United States and internationally. Street prices of diverted prescription opioids can provide an indicator of drug availability, demand, and abuse potential, but these data can be difficult to collect. Crowdsourcing is a rapid and cost-effective way to gather information about sales transactions. We sought to determine whether crowdsourcing can provide accurate measurements of the street price of diverted prescription opioid medications. OBJECTIVE: To assess the possibility of crowdsourcing black market drug price data by cross-validation with law enforcement officer reports. METHODS: Using a crowdsourcing research website (StreetRx), we solicited data about the price that site visitors paid for diverted prescription opioid analgesics during the first half of 2012. These results were compared with a survey of law enforcement officers in the Researched Abuse, Diversion, and Addiction-Related Surveillance (RADARS) System, and actual transaction prices on a "dark Internet" marketplace (Silk Road). Geometric means and 95% confidence intervals were calculated for comparing prices per milligram of drug in US dollars. In a secondary analysis, we compared prices per milligram of morphine equivalent using standard equianalgesic dosing conversions. RESULTS: A total of 954 price reports were obtained from crowdsourcing, 737 from law enforcement, and 147 from the online marketplace. Correlations between the 3 data sources were highly linear, with Spearman rho of 0.93 (P<.001) between crowdsourced and law enforcement, and 0.98 (P<.001) between crowdsourced and online marketplace. On StreetRx, the mean prices per milligram were US$3.29 hydromorphone, US$2.13 buprenorphine, US$1.57 oxymorphone, US$0.97 oxycodone, US$0.96 methadone, US$0.81 hydrocodone, US$0.52 morphine, and US$0.05 tramadol. The only significant difference between data sources was morphine, with a Drug Diversion price of US$0.67/mg (95% CI 0.59-0.75) and a Silk Road price of US$0.42/mg (95% CI 0.37-0.48). Street prices generally followed clinical equianalgesic potency. CONCLUSIONS: Crowdsourced data provide a valid estimate of the street price of diverted prescription opioids. The (ostensibly free) black market was able to accurately predict the relative pharmacologic potency of opioid molecules.

Reduced abuse, therapeutic errors, and diversion following reformulation of extended-release oxycodone in 2010.

UNLABELLED: This study evaluated changes in abuse exposures, therapeutic error exposures, and diversion into illegal markets associated with brand extended-release oxycodone (ERO) following introduction of reformulated ERO. Original ERO and reformulated ERO street prices also were compared. Data from the Poison Center and Drug Diversion programs of the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS) System were used. Quarterly rates 2 years prior to introduction of reformulated ERO (October 2008 through September 2010) were compared to quarterly rates after introduction (October 2010 through March 2012) using negative binomial regression. Street prices were compared using a mixed effects linear regression model. Following reformulated ERO introduction, poison center ERO abuse exposures declined 38% (95% confidence interval [CI]: 31-45) per population and 32% (95% CI: 24-39) per unique recipients of dispensed drug. Therapeutic error exposures declined 24% (95% CI: 15-31) per population and 15% (95% CI: 6-24) per unique recipients of dispensed drug. Diversion reports declined 53% (95% CI: 41-63) per population and 50% (95% CI: 39-59) per unique recipients of dispensed drug. Declines exceeded those observed for other prescription opioids in aggregate. After its introduction, the street price of reformulated ERO was significantly lower than original ERO. PERSPECTIVE: This article indicates that the abuse, therapeutic errors, and diversion of ERO declined following the introduction of a tamper-resistant reformulation of the product. Reformulating abused prescription opioids to include tamper-resistant properties may be an effective approach to reduce abuse of such products.

Assessment of the abuse of tapentadol immediate release: the first 24 months.

OBJECTIVE: Prescription opioid analgesics play an important role in the management of moderate to severe pain. An unintended consequence of prescribing opioid analgesics is the abuse and diversion of these medications. The authors estimated abuse and diversion rates for tapentadol immediate release (IR) compared with oxycodone, hydrocodone, and tramadol during the first 24 months of tapentadol IR availability. METHODS: The Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS®) System measures rates of prescription opioid abuse and diversion throughout the United States. Quarterly data from the Poison Center, Drug Diversion, Opioid Treatment, and Survey of Key Informants' Patients (SKIP) programs were plotted to visually compare the rates of tapentadol IR abuse and diversion with those of other opioid analgesics from July 2009 through June 2011 using both cases per 100,000 population and per 1,000 unique recipients of dispensed drug (URDD) as denominators. Trends in abuse and diversion rates over time were determined using a linear regression model of rate versus time. RESULTS: During the 24 months following its introduction, tapentadol IR had very low population-based rates of abuse and diversion that were similar to rates for tramadol and lower than rates for oxycodone and hydrocodone. Rates of tapentadol IR abuse and diversion based on URDD were variable by program due to changes in market share and had not stabilized as of June 2011. CONCLUSIONS: Rates of tapentadol IR abuse and diversion have been low during the first 24 months after its launch. Continued monitoring of trends in these data is warranted.

Requirements and definitions in conflict of interest policies of medical journals.

CONTEXT: Conflicts of interest (COIs) may influence medical literature. However, it is unclear whether medical journals have consistent policies for defining and soliciting COI disclosures. OBJECTIVE: To determine the prevalence of author COI policies, requirements for signed disclosure statements, and variability in COI definitions among medical journals. DESIGN: A cross-sectional survey of Instructions for Authors and manuscript submission documents, including authorship responsibility forms, for high-impact medical journals across 35 subject categories available from March through October 2008. MAIN OUTCOME MEASURE: Presence of language referring to COI disclosure in the Instructions for Authors or manuscript submission documents. RESULTS: Of 256 journals, 89% had author COI policies. Fifty-four percent required authors to sign a disclosure statement, and 77% provided definitions of COI. Most definitions were limited to direct financial relationships; a minority of journals requested disclosure of other potential conflicts such as personal relationships (42%), paid expert testimony (42%), relationships with other organizations (26%), or travel grants (12%). The prevalence of policies varied by subject category: all internal medicine, respiratory medicine, and toxicology journals studied had comprehensive COI definitions, with 19 of these 24 journals requiring signed disclosure attestations. In contrast, 6 of 19 geriatrics, radiology, and rehabilitation journals requested author COI disclosure. Most journals that officially endorsed International Committee of Medical Journal Editors guidelines had COI policies (68/69), compared with 84% of journals not endorsing the guidelines (158/187). CONCLUSIONS: In 2008, most medical journals with relatively high impact factors had author COI policies available for public review. Among journals, there was substantial variation in policies for solicitation of author COIs and in definitions of COI.