Abuse of tapentadol compared to other atypical opioids among individuals entering treatment for opioid use disorders.

OBJECTIVE: Tapentadol is an atypical opioid analgesic thought to have dual mechanisms of action: µ-receptor agonism and inhibition of norepinephrine reuptake. Unlike other atypical opioids, tapentadol is a schedule II-controlled substance. We compared the prevalence of abuse (use to get high) of tapentadol to other atypical opioids used to treat pain (buprenor-phine and tramadol). DESIGN: An observational, serial cross-sectional study. SETTING: Individuals enrolling in treatment programs for opioid use disorder in 2019. Each completed a self-administered, paper questionnaire assessing prescription drug abuse and illegal drug use within 1 week of enrollment. MAIN OUTCOME MEASURES: Indication of past month abuse of tapentadol or comparator drugs on a self-administered ques-tionnaire. RESULTS: There were 6,987 respondents. Unadjusted and utilization-adjusted logistic regression models were used to compare odds of endorsement of tapentadol to tramadol and buprenorphine products indicated for the management of pain. Unadjusted abuse prevalence was 0.20 percent for total tapentadol (0.03 percent for NUCYNTA® and 0.06 percent for NUCYNTA ER). Relative to total tapentadol, the odds of abuse of buprenorphine for pain was 2.9 times greater (95 percent CI: 1.6 to 5.3, p < 0.001), and for tramadol, 43.1 times greater (95 percent CI: 25.3 to 73.3, p < 0.001). Adjusting for prescriptions dispensed, differences in odds of abuse were not statistically significant (odds ratio (OR) = 1.6, 95 per-cent CI: 0.9 to 3.0, p = 0.108 for buprenorphine for pain and OR = 0.7, 95 percent CI: 0.4 to 1.2, p = 0.209 for tramadol). CONCLUSIONS: Tapentadol use to get high is less frequent than other atypical opioids. Findings suggest tapentadol is rarely the primary drug abused by an individual.

Differences in severity of poison centers exposures involving XTAMPZA® ER versus other opioid analgesics.

Aims: Xtampza® ER (Collegium Pharmaceutical, MA, USA) is an abuse-deterrent formulation (ADF) of oxycodone intended to deter tampering for use by unintended routes of administration. We assessed whether Xtampza ER exposures were less likely to result in severe medical outcomes relative to other opioid analgesic exposures. Materials & methods: Exposures reported to participating poison centers between 2016 and 2021 inclusive that were followed to a known medical outcome were analyzed. Xtampza ER was compared with other ADF opioids, non-ADF extended-release opioids, single-entity oxycodone immediate-release, unspecified oxycodone and unspecified morphine. Results & conclusion: No Xtampza ER exposures involved unintended routes of administration. Xtampza ER exposures were less likely to be abuse, misuse or suspected suicidal, and medical outcomes were less severe than comparators.

Initiation Patterns and Transitions Among Adults Using Stimulant Drugs: Latent Transition Analysis.

BACKGROUND: The fourth wave of the drug overdose epidemic in the United States includes increasing rates of stimulant-involved overdose. Recent studies of transitions leading to stimulant misuse have shown complex patterns that are not universally applicable because they have isolated individual populations or individual behaviors. A comprehensive analysis of transitions between behaviors and the associations with present-day problematic drug use has not been conducted. OBJECTIVE: This study aims to determine whether adults from the general population who use stimulants initiate use through a heterogeneous combination of behaviors and quantify the association between these typologies with present-day problematic drug use. METHODS: Individuals who have reported use of any stimulant in their lifetime were recruited from the 2021 Survey of Nonmedical Use of Prescription Drugs Program, a nationally representative web-based survey on drug use, to participate in a rapid follow-up survey about their past stimulant use. Individuals were asked which stimulants they used, the reasons for use, the routes of administration, and the sources of the stimulant. For each stimulant-related behavior, they were asked at what age, between 6 and 30 years, they initiated each behavior in a 6-year time window. A latent transition analysis was used to characterize heterogeneity in initiation typologies. Mutually exclusive pathways of initiation were identified manually by the researchers. The association of these pathways with present-day problematic drug use was calculated using logistic regression adjusted by the current age of the respondent. RESULTS: From a total of 1329 participants, 740 (55.7%) reported lifetime prescription stimulant use and 1077 (81%) reported lifetime illicit stimulant use. Three typologies were identified. The first typology was characterized by illicit stimulant initiation to get high, usually via oral or snorting routes and acquisition from friends or family or a dealer (illicit experimentation). The second typology was characterized by low, but approximately equal probabilities of initiating 1-2 new behaviors in a time window, but no singular set of behaviors characterized the typology (conservative initiation). The third was characterized by a high probability of initiating many diverse combinations of behaviors (nondiscriminatory experimentation). The choice of drug initiated was not a strong differentiator. Categorization of pathways showed those who were only in an illicit experimentation status (reference) had the lowest odds of having severe present-day problematic drug use. Odds were higher for a conservative initiation-only status (odds ratio [OR] 1.84, 95% CI 1.14-2.94), which is higher still for those moving from illicit experimentation to conservative initiation (OR 3.50, 95% CI 2.13-5.74), and highest for a nondiscriminatory experimentation status (OR 5.45, 95% CI 3.39-8.77). CONCLUSIONS: Initiation of stimulant-related use behaviors occurred across many time windows, indicating that multiple intervention opportunities are presented. Screening should be continued throughout adulthood to address unhealthy drug use before developing into full substance use disorders.

Differing Behaviors Around Adult Nonmedical Use of Prescription Stimulants and Opioids: Latent Class Analysis.

BACKGROUND: The availability of central nervous system stimulants has risen in recent years, along with increased dispensing of stimulants for treatment of, for example, parent-reported attention-deficit/hyperactivity disorder in children and new diagnoses during adulthood. Typologies of drug use, as has been done with opioids, fail to include a sufficient range of behavioral factors to contextualize person-centric circumstances surrounding drug use. Understanding these patterns across drug classes would bring public health and regulatory practices toward precision public health. OBJECTIVE: The objective of this study was to quantitatively delineate the unique behavioral profiles of adults who currently nonmedically use stimulants and opioids using a latent class analysis and to contrast the differences in findings by class. We further evaluated whether the subgroups identified were associated with an increased Drug Abuse Screening Test-10 (DAST-10) score, which is an indicator of average problematic drug use. METHODS: This study used a national cross-sectional web-based survey, using 3 survey launches from 2019 to 2020 (before the COVID-19 pandemic). Data from adults who reported nonmedical use of prescription stimulants (n=2083) or prescription opioids (n=6127) in the last 12 months were analyzed. A weighted latent class analysis was used to identify the patterns of use. Drug types, motivations, and behaviors were factors in the model, which characterized unique classes of behavior. RESULTS: Five stimulant nonmedical use classes were identified: amphetamine self-medication, network-sourced stimulant for alertness, nonamphetamine performance use, recreational use, and nondiscriminatory behaviors. The drug used nonmedically, acquisition through a friend or family member, and use to get high were strong differentiators among the stimulant classes. The latter 4 classes had significantly higher DAST-10 scores than amphetamine self-medication (P<.001). In addition, 4 opioid nonmedical use classes were identified: moderate pain with low mental health burden, high pain with higher mental health burden, risky behaviors with diverse motivations, and nondiscriminatory behaviors. There was a progressive and significant increase in DAST-10 scores across classes (P<.001). The potency of the opioid, pain history, the routes of administration, and psychoactive effect behaviors were strong differentiators among the opioid classes. CONCLUSIONS: A more precise understanding of how behaviors tend to co-occur would improve efficacy and efficiency in developing interventions and supporting the overall health of those who use drugs, and it would improve communication with, and connection to, those at risk for severe drug outcomes.

Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement.

Importance: The US and Canada currently have no formal published nationwide guidelines for specialists in poison information or emergency departments for the management of acetaminophen poisoning, resulting in significant variability in management. Objective: To develop consensus guidelines for the management of acetaminophen poisoning in the US and Canada. Evidence Review: Four clinical toxicology societies (America's Poison Centers, American Academy of Clinical Toxicology, American College of Medical Toxicology, and Canadian Association of Poison Control Centers) selected participants (n = 21). Led by a nonvoting chairperson using a modified Delphi method, the panel created a decision framework and determined the appropriate clinical management of a patient with acetaminophen poisoning. Unique to this effort was the collection of guidelines from most poison centers in addition to systematic collection and review of the medical literature. Comments from review by external organizations were incorporated before the guideline was finalized. The project began in March 2021 and ended in March 2023. Findings: The search retrieved 84 guidelines and 278 publications. The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen. In addition, the panel addressed extended-release formulation, high-risk ingestion, coingestion of anticholinergics or opioids, age younger than 6 years, pregnancy, weight greater than 100 kg, and intravenous acetaminophen use. Differences from current US practice include defining acute ingestion as an ingestion presentation from 4 to 24 hours after overdose was initiated. A revised form of the Rumack-Matthew nomogram was developed. The term massive ingestion was replaced with the term high-risk ingestion and denoted by a specific nomogram line. Other recommendations include specific criteria for emergency department triage, laboratory evaluation and monitoring parameters, defining the role of gastrointestinal decontamination, detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria for acetylcysteine treatment, as well as criteria for consultation with a clinical toxicologist. Finally, specific treatment considerations, including acetylcysteine dosing, fomepizole administration, and considerations for extracorporeal elimination and transplant evaluation, were addressed. Conclusions and Relevance: This qualitative study provides a consensus statement on consistent evidence-based recommendations for medical, pharmacy, and nursing education and practice to optimize care of patients with acetaminophen poisoning.

Total CroFab and Anavip Antivenom Vial Administration in US Rattlesnake Envenomations: 2019-2021.

INTRODUCTION: In 2018, Anavip became available for the treatment of rattlesnake envenomations in the USA. No comparisons between the treatment characteristics of patients have been made since Anavip and CroFab have both been widely available. The objective of this study was to compare the number of antivenom vials administered of CroFab and Anavip during the treatment of rattlesnake envenomations in the USA. METHODS: This was a secondary analysis of rattlesnake envenomations utilizing the North American Snakebite Registry (NASBR) from 2019 through 2021. Frequencies and proportions were used to summarize demographics and baseline clinical characteristics. The primary outcome was total antivenom vials administered during treatment. Secondary outcomes included the number antivenom administration events, total treatment time, and hospital length of stay. RESULTS: Two hundred ninety-one rattlesnake envenomations were analyzed; most occurred in the Western USA (n = 279, 96 %). One hundred one patients (35%) received only CroFab, 110 (38%) received Anavip only, and 80 (27%) received both products. The median number of vials used was 10 for CroFab, 18 for Anavip, and 20 for both antivenoms. More than one antivenom administration was necessary in thirty-nine (39%) patients that received only CroFab and 76 (69%) patients that received Anavip only. The median total treatment time was 5.5 hours for CroFab, 6.5 for Anavip, and 15.5 hours when both antivenoms were administered. All antivenom groups had a median hospital length of stay of 2 days. CONCLUSIONS: Rattlesnake envenomated patients in the Western USA treated with CroFab had fewer antivenom vials and fewer antivenom administrations compared to patients treated with Anavip.

Clustering patterns in polysubstance mortality in the United States in 2017: a multiple correspondence analysis of death certificate data.

PURPOSE: The main goal of this analysis was to identify mortality patterns apparent when many drug classes are analyzed together. METHODS: The Drug Involved Mortality database is a registry of drug terms mentioned on death certificates of all drug-related deaths in the United States. Means of total number of drugs involved and percentages of specific drug combinations were calculated. Dimensionality reduction using multiple correspondence analysis and hierarchical clustering identified clusters of drugs listed on death certificates. RESULTS: An average of 2.4 specific drugs were listed on death certificates in 2017. For 9 of the top 10 drugs involved, over 80% of deaths involved at least one other drug. As expected, opioid drugs and psychostimulants clustered together, but other psychoactive substances (non-opioid analgesics, sedatives, antidepressants, antipsychotics) clustered together into multi-class groups. Other drugs (e.g., acetaminophen, oxymorphone) were frequently involved in polysubstance death, but did not cluster with any other specific drug. Deaths involving illicit drugs listed fewer drugs than deaths involving prescription drugs. CONCLUSIONS: While individual drug substances might contribute to many deaths (e.g., fentanyl), polysubstance mortality is more common than single substance mortality. Multidimensional analyses integrating all drugs involved are useful to identify uncommon patterns of overdose and changing trends.

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.

Evaluation of Cannabis Use Among US Adults During the COVID-19 Pandemic Within Different Legal Frameworks.

This cross-sectional study analyzes the prevalence of cannabis use by US adults during the COVID-19 pandemic within different legal frameworks and evaluates differences in associated behaviors.

Population pharmacokinetic analysis of acetaminophen overdose with immediate release, extended release and modified release formulations.

OBJECTIVES: The introduction of delayed release formulations of acetaminophen (APAP) has created concern about the role of formulation in overdose. We examined the APAP overdose pharmacokinetic (PK) profiles to assess the role of dose, coingestants and formulation: immediate release (IR), extended release (ER), and modified release (MR) on APAP pharmacokinetic measures. METHODS: We collected by-subject APAP PK data: subject description, timed blood APAP concentrations, dose, and coingestants. We sought both overdose and randomized controlled trials (RCTs) for supratherapeutic doses involving ER or MR formulations. Data analysis and simulation used the non-linear mixed-effects modeling program NONMEM-version 7.4. RESULTS: The final dataset comprised 3,033 [APAP] from 356 subjects and 15 sources including 3 RCTs (179 subjects receiving IR, 122 ER, 65 MR). The final population PK (PopPK) model was a linear 2-compartment model with first-order (oral) absorption. Covariate relationships included: APAP absorption rate and bioavailability decreased with increased oral dose (p < 0.00005) for all 3 formulations (MR > ER > IR). Post hoc analyses showed opioid coingestant increased exposure (area under the curve, AUC) by factor of 1.6. Simulations of 100 g vs 10 g doses for IR, ER and MR showed overdose of the ER formulation exhibits slower absorption and lower Cmax, overall exposure (AUC) is less than 80% of an equivalent dose of IR acetaminophen. The overall exposure for the MR formulation is less than 70% of an equivalent dose of IR. CONCLUSIONS: Acetaminophen ER and MR formulations have slower absorption and decreased bioavailability leading to a lower Cmax and later Tmax than the IR formulation. These results have potential clinical implications because delayed absorption could confound use of the Rumack-Matthew nomogram by underestimating the severity of ingestion early in the course of treatment.

Genetic variants associated with ALT elevation from therapeutic acetaminophen.

BACKGROUND: Several studies have suggested genetic variants associated with acetaminophen induced liver injury (DILI) following overdose. Genetic variation associated with acetaminophen-induced alanine aminotransferase elevation during therapeutic dosing has not been examined. METHODS: We performed genetic analyses on patients that ingested therapeutic doses of 4 grams of acetaminophen for up to 16 days. We examined 20 genes previously implicated in the metabolism of acetaminophen or the development of immune-mediated DILI using the Illumina Multi-Ethnic Global Array 2. Autosomes were aligned and imputed using TOPMed. A candidate gene region analysis was performed by testing each gene individually using linkage disequilibrium (LD) pruned variants with the adaptive sum of powered scores (aSPU) test from the aSPU R package. The highest measured ALT during therapy, the maximum ALT, was used as the outcome. RESULTS: 192 subjects taking therapeutic APAP were included in the genetic analysis. 136 (70.8%) were female, 133 (69.2%) were Caucasian race, and the median age was 34 years (IQR: 26, 46). Age > 50 years was the only clinical factor associated with maximum ALT increase. Variants in SULT1E1, the gene responsible for Sulfotransferase Family 1E Member 1 enzyme production, were associated with maximum ALT. No single variant drove this association, but rather the association was due to the additive effects of numerous variants within the gene. No other genes were associated with maximum ALT increase in this cohort. CONCLUSION: Acetaminophen induced ALT elevation at therapeutic doses was not associated with variation in most genes associated with acetaminophen metabolism or immune-induced DILI in this cohort. The role of SULT1E1 polymorphism in acetaminophen-induced elevated ALT needs further examination.

The Roles of Antidotes in Emergency Situations.

Management of the acutely poisoned patient requires supportive care and timely administration of antidotes to minimize ongoing toxicity and mortality. New applications for old antidotes include utilization of methylene blue and hydroxocobalamin in vasoplegia. Fomepizole is also being evaluated as a potential adjunct in acetaminophen toxicity. Other advancements include individualized acetylcysteine dosing regimens for acetaminophen toxicity and carnitine supplementation in valproic acid toxicity. Additional antidote considerations include administration of lipid emulsion in lipophilic xenobiotic exposure not responsive to standard resuscitative modalities. These expert recommendations provide guidance for providers caring for the acutely poisoned patient.

Changes in Hydrocodone Misuse Exposures Reported to U.S. Poison Centers Following Rescheduling in 2014.

BACKGROUND: In 2014, the Drug Enforcement Administration rescheduled hydrocodone combination products to Schedule II to reduce nonmedical use and diversion. METHODS: The impact of rescheduling was assessed using quarterly data from 2011 through 2019 from the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS®) System Poison Center Program and IQVIATM Longitudinal Prescription Data. Trends and immediate changes in prescriptions dispensed and misuse exposures before and after rescheduling involving hydrocodone, oxycodone, and other Schedule II opioid analgesics were calculated using segmented regression. RESULTS: Hydrocodone prescriptions were stable pre-rescheduling, decreased by 2.7% (95% CI: -3.6%, -1.8%, p < 0.0001) per quarter post-rescheduling. Misuse exposures involving hydrocodone were decreasing by 3.2% (95% CI: -3.9%, -2.4%, p < 0.0001) per quarter pre-rescheduling and decreased by 4.9% (95% CI: -5.5%, -4.2%, p < 0.0001) post-rescheduling. Immediate decreases in hydrocodone prescriptions and misuse exposure rates in 2014Q4 compared to 2014Q3 were significant and different from oxycodone or other Schedule II opioids. Schedule II opioid analgesics prescriptions in aggregate were stable prior to rescheduling, decreased by 10.8% (95%CI: -14.0%, -7.6%, p < 0.0001) immediately after the rescheduling, and decreased by 2.3% per quarter (95% CI: -3.1%, -1.5%, p < 0.0001) subsequently. Misuse exposures involving these opioids were decreasing by 3.3% (95% CI: -4.1%, -2.5%, p < 0.0001) prior to rescheduling then by 2.8%, (95% CI: -3.4%, -2.2%, p < 0.0001) after rescheduling. The immediate change in misuse was not significant. CONCLUSIONS: Rescheduling corresponded with changes in hydrocodone prescribing and misuse not offset by increases in other Schedule II opioid analgesics. Misuse exposures for hydrocodone and comparators were decreasing prior to rescheduling with little change post-intervention.

The association between the availability of over the counter codeine and the prevalence of non-medical use.

PURPOSE: To investigate the prevalence of non-medical use (NMU) of codeine in Germany, Italy, Spain and the UK and whether availability of OTC codeine has any association with NMU of the drug. METHODS: Data collected in the online Survey of Non-Medical Use of Prescription Drugs, in surveys launched in the second half of 2018 from (Germany (n = 14,969), Italy, (n = 9974), Spain (n = 9912) and the UK (n = 9819) were analysed. For each survey, the estimated prevalence and 95% confidence interval (CI) of respondents reporting NMU of prescription and/or OTC codeine within the last 12 months were calculated and compared. RESULTS: The prevalence of last 12-month NMU in Spain was 12.6% (95% CI 11.7-13.6) for prescription codeine, 6.3% (5.6-7.0) for OTC codeine and 16.1% (15.1-17.3) for any codeine (prescription and/or OTC). The prevalence of last 12-month NMU in the UK was 5.4% (4.9-5.8) for prescription codeine, 4.5% (4.1-5.0) for OTC codeine and 8.3% (7.8-8.9) for any codeine (prescription and/or OTC). The prevalence of last 12-month NMU for prescription codeine was 2.1% (1.9-2.4) in Germany and 1.9% (1.7-2.2) in Italy. CONCLUSION: The prevalence of last 12-month NMU of any codeine product is approximately eight times greater in Spain and four times greater in the UK compared to Germany and Italy where the drug is only available by prescription. While other factors may contribute, these findings suggest that availability of codeine OTC is associated with greater NMU.

Association Between Prescription Opioid Therapy for Noncancer Pain and Hepatitis C Virus Seroconversion.

Importance: Initiation of injection drug use may be more frequent among people dispensed prescription opioid therapy for noncancer pain, potentially increasing the risk of hepatitis C virus (HCV) acquisition. Objective: To assess the association between medically dispensed long-term prescription opioid therapy for noncancer pain and HCV seroconversion among individuals who were initially injection drug use-naive. Design, Setting, and Participants: A population-based, retrospective cohort study of individuals tested for HCV in British Columbia, Canada, with linkage to outpatient pharmacy dispensations, was conducted. Individuals with an initial HCV-negative test result followed by 1 additional test between January 1, 2000, and December 31, 2017, and who had no history of substance use at baseline (first HCV-negative test), were included. Participants were followed up from baseline to the last HCV-negative test or estimated date of seroconversion (midpoint between HCV-positive and the preceding HCV-negative test). Exposures: Episodes of prescription opioid use for noncancer pain were defined as acute (<90 days) or long-term (≥90 days). Prescription opioid exposure status (long-term vs prescription opioid-naive/acute) was treated as time-varying in survival analyses. In secondary analyses, long-term exposure was stratified by intensity of use (chronic vs. episodic) and by average daily dose in morphine equivalents (MEQ). Main Outcomes and Measures: Multivariable Cox regression models were used to assess the association between time-varying prescription opioid status and HCV seroconversion. Results: A total of 382 478 individuals who had more than 1 HCV test were included, of whom more than half were female (224 373 [58.7%]), born before 1974 (201 944 [52.8%]), and younger than 35 years at baseline (196 298 [53.9%]). Participants were followed up for 2 057 668 person-years and 1947 HCV seroconversions occurred. Of the participants, 41 755 people (10.9%) were exposed to long-term prescription opioid therapy at baseline or during follow-up. The HCV seroconversion rate per 1000 person-years was 0.8 among the individuals who were prescription opioid-naive/acute (1489 of 1947 [76.5%] seroconversions; 0.4% seroconverted within 5 years) and 2.1 with long-term prescription opioid therapy (458 of 1947 [23.5%] seroconversions; 1.1% seroconverted within 5 years). In multivariable analysis, exposure to long-term prescription opioid therapy was associated with a 3.2-fold (95% CI, 2.9-3.6) higher risk of HCV seroconversion (vs prescription opioid-naive/acute). In separate Cox models, long-term chronic use was associated with a 4.7-fold higher risk of HCV seroconversion (vs naive/acute use 95% CI, 3.9-5.8), and long-term higher-dose use (≥90 MEQ) was associated with a 5.1-fold higher risk (vs naive/acute use 95% CI, 3.7-7.1). Conclusions and Relevance: In this cohort study of people with more than 1 HCV test, long-term prescription opioid therapy for noncancer pain was associated with a higher risk of HCV seroconversion among individuals who were injection drug use-naive at baseline or at prescription opioid initiation. These results suggest injection drug use initiation risk is higher among people dispensed long-term therapy and may be useful for informing approaches to identify and prevent HCV infection. These findings should not be used to justify abrupt discontinuation of long-term therapy, which could increase risk of harms.

Comparison of hospital claims and poison center data to evaluate health impact of opioids, cannabis and synthetic cannabinoids.

INTRODUCTION: Over the past 10 years, opioids and cannabis have garnered significant attention due to misuse and legalization trends. Different datasets and surveillance mechanisms can lead to different conclusions the due to a variety of factors. The primary objective of this study was to compare and describe trends of opioid, cannabis, and synthetic cannabinoid-related healthcare encounters and poison center (PC) cases in Colorado, a state that has legalized cannabis. METHODS: This was a retrospective study comparing hospital claims data (Colorado Hospital Association (CHA)) and poison center cases to describe opioid, cannabis and synthetic cannabinoid-related healthcare encounters and exposures in Colorado from 2013 to 2017 using related genetic codes and International Statistical Classification of Disease codes. RESULTS: Both datasets observed increases in cannabis related encounters and exposures after recreational cannabis legalization in 2014. CHA reported an increase for cannabis-related ER visits from 14,109 in 2013 to 18,118 in 2017 while PC noted a 74.4% increase in cannabis-related cases (125 to 218). CHA inpatient visits associated with cannabis also increased (8311 in 2013 to 14,659 in 2017). On the other hand, Opioid-related exposures to the PC fell (1092 in 2013 to 971 in 2017) while both Opioid-related ER visits (8580 in 2013 to 12,928 in 2017) and inpatient visits in CHA increased (9084 in 2013 to 13,205). CONCLUSIONS: This study demonstrates the differences in surveillance methodology for concurrent drug abuse epidemics using hospital claims and PC data. Both systems provide incomplete reports, but in combination can provide a more complete picture.

Adverse Events Related to Accidental Unintentional Ingestions From Cough and Cold Medications in Children.

OBJECTIVES: Previous research has demonstrated that accidental unsupervised ingestions (AUIs) were responsible for the majority of cough and cold medication (CCM) ingestions leading to significant adverse events (AEs) in children. The objective of this analysis was to characterize the role of AUIs in the morbidity associated with CCM exposure in children. METHODS: This surveillance study collected data from 5 United States data sources from 2009 to 2016, in children younger than 6 years with an AE from an AUI involving at least 1 CCM over-the-counter pharmaceutical ingredient. An expert panel reviewed each case to determine causality. RESULTS: From 4756 total cases reviewed, 3134 (65.9%) had an AE from an AUI determined to be at least potentially related to a CCM ingredient. The majority (61.3%) of cases occurred in children aged 2 to younger than 4 years. Most exposures occurred in the child's own residence (94.9%), and 43.8% were admitted to a health care facility (22.0% to a critical care unit). Dextromethorphan and diphenhydramine, when packaged alone or in combination products, contributed to 96.0% of AUIs. The most common specific products involved were single-ingredient pediatric liquid diphenhydramine (30.1%) and single-ingredient pediatric liquid dextromethorphan (21.4%). There were 3 deaths from solid diphenhydramine formulations. CONCLUSIONS: There continues to be opportunities for the implementation of interventions to prevent AUIs of CCM in children. Additional emphasis on engineering controls, such as flow restrictors for liquid formulations targeting diphenhydramine and dextromethorphan products, represent additional opportunities to further reduce AEs from AUIs of CCM.