The toxicology Tower of Babel: why we need to agree on a lexicon in prescription opioid research

Descriptive Analysis of Inpatient and Outpatient Cohorts Seeking Treatment After Prescription Opioid Misuse and Medical Toxicology Evaluation

INTRODUCTION

Medical toxicology expertise has expanded into the addiction medicine realm including outpatient medication for opioid use disorder (MOUD) and addiction treatment. Concomitantly, the emergency department (ED) and hospital are increasingly seen as important sites for the screening, prevention, and treatment of patients with substance use disorders and addiction. This analysis seeks to characterize patients seen by medical toxicologists for opioid use and opioid use disorder (OUD) in the ED and inpatient consultation setting (inpatient) versus in the OUD clinic (outpatient) setting.

METHODS

We searched the American College of Medical Toxicology's Toxicology Investigators Consortium Case Registry, a prospective, de-identified, national dataset that includes patients receiving medical toxicology consultation following prescription opioid misuse. The dataset also includes patients seen in outpatient MOUD clinics during the same period between June 2013 and November 2015. Intentional self-harm patients were excluded. We analyzed medical history, drug use patterns, and other factors with odds ratios and confidence intervals.

RESULTS

Of 110 patients identified, 60 (54.5%) were inpatients and 50 (45.5%) outpatients. Mean age (39 years), gender (68% male), and race breakdown (60% white/non-Hispanic) were similar. The outpatient group was more likely to have Medicare/Medicaid coverage (p<0.0001). By history, the outpatient group was more likely to have past alcohol misuse, intravenous drug use, prescription drug misuse, and prescription opioid misuse. Most inpatient group members sought a recreational high compared to avoiding withdrawal or treating dependence in the outpatient group.

CONCLUSION

Patients treated in the outpatient compared to inpatient setting were more likely to report adverse sequelae from their drug use including long-term drug use, depression, previous rehabilitation attempts, and seeking to avoid withdrawal.

A theoretical framework and nomenclature to characterize the iatrogenic contribution of therapeutic opioid exposure to opioid induced hyperalgesia, physical dependence, and opioid use disorder

Opioid use, misuse, and risky use contribute to a critically important and complex crisis in current healthcare. Consequences of long-term opioid use, including opioid induced hyperalgesia, physical dependence, and opioid use disorder, can be considered iatrogenic, or partially iatrogenic, in cases where therapeutic opioid exposures were contributory. Research investigation and presumptive clinical action are needed to attenuate the iatrogenic component of the opioid crisis; treatment of individuals already suffering from opioid use disorder will not prevent incident cases. This work will be challenged by a remarkably high degree of complexity involving myriad and highly variable factors along the continuum from initial opioid exposure to long-term opioid use. An organized view of this complex problem should accelerate the pace of innovation and facilitate clinical implementation of research findings. Herein, we propose a theoretical framework and modern nomenclature for characterizing therapeutic opioid exposure and the degree to which it contributes iatrogenically to adverse outcomes. In doing so, we separate the role of exposure from other factors contributing to long-term opioid use, clarify the relationship between opioid exposure and outcomes, emphasize that exposure source is an important consideration for health services research and practice in the areas of pain treatment and opioid prevention, and recommend terminology necessary to quantify therapeutic opioid exposure separately from nonmedical exposure.

Recommendations for the Investigation, Diagnosis, and Certification of Deaths Related to Opioid Drugs

The American College of Medical Toxicology and the National Association of Medical Examiners convened an expert panel to generate evidence-based recommendations for the practice of death investigation and autopsy, toxicological analysis, interpretation of the toxicology findings, and death certification to improve the precision of death certificate data available for public health surveillance. The panel finds the following: 1. A complete autopsy is necessary for optimal interpretation of toxicology results, which must also be considered in the context of the circumstances surrounding death, medical history, and scene findings. 2. A complete scene investigation extends to reconciliation of prescription information and pill counts. 3. Blood, urine, and vitreous humor, when available, should be retained in all cases. Blood from the femoral vein is preferable to blood from other sites. 4. A toxicological panel should be comprehensive and include opioid and benzodiazepine analytes, as well as other potent depressant, stimulant, and antidepressant medications. 5. Interpretation of postmortem opioid concentrations requires correlation with medical history, scene investigation, and autopsy findings. 6. If death is attributed to any drug or combination of drugs (whether as cause or contributing factor), the certifier should list all the responsible substances by generic name in the autopsy report and on the death certificate. 7. The best classification for manner in deaths due to the misuse or abuse of opioids without any apparent intent of self-harm is “accident.” Reserve “undetermined” as the manner for the rare cases in which evidence exists to support more than one possible determination.