Comparative out-of-hospital mortality of long-acting opioids prescribed for non-cancer pain: A retrospective cohort study

Predictors of fatal and nonfatal overdose after prescription of opioids for chronic pain: a systematic review and meta-analysis of observational studies

BACKGROUND

Higher doses of opioids, mental health comorbidities, co-prescription of sedatives, lower socioeconomic status and a history of opioid overdose have been reported as risk factors for opioid overdose; however, the magnitude of these associations and their credibility are unclear. We sought to identify predictors of fatal and nonfatal overdose from prescription opioids.

METHODS

We systematically searched MEDLINE, Embase, CINAHL, PsycINFO and Web of Science up to Oct. 30, 2022, for observational studies that explored predictors of opioid overdose after their prescription for chronic pain. We performed random-effects meta-analyses for all predictors reported by 2 or more studies using odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Twenty-eight studies (23 963 716 patients) reported the association of 103 predictors with fatal or nonfatal opioid overdose. Moderate- to high-certainty evidence supported large relative associations with history of overdose (OR 5.85, 95% CI 3.78-9.04), higher opioid dose (OR 2.57, 95% CI 2.08-3.18 per 90-mg increment), 3 or more prescribers (OR 4.68, 95% CI 3.57-6.12), 4 or more dispensing pharmacies (OR 4.92, 95% CI 4.35-5.57), prescription of fentanyl (OR 2.80, 95% CI 2.30-3.41), current substance use disorder (OR 2.62, 95% CI 2.09-3.27), any mental health diagnosis (OR 2.12, 95% CI 1.73-2.61), depression (OR 2.22, 95% CI 1.57-3.14), bipolar disorder (OR 2.07, 95% CI 1.77-2.41) or pancreatitis (OR 2.00, 95% CI 1.52-2.64), with absolute risks among patients with the predictor ranging from 2-6 per 1000 for fatal overdose and 4-12 per 1000 for nonfatal overdose.

INTERPRETATION

We identified 10 predictors that were strongly associated with opioid overdose. Awareness of these predictors may facilitate shared decision-making regarding prescribing opioids for chronic pain and inform harm-reduction strategies SYSTEMATIC REVIEW REGISTRATION: Open Science Framework (https://osf.io/vznxj/).

Pharmacological data science perspective on fatal incidents of morphine treatment

Morphine prescribed for analgesia has caused drug-related deaths at an estimated incidence of 0.3% to 4%. Morphine has pharmacological properties that make it particularly difficult to assess the causality of morphine administration with a patient's death, such as its slow transfer between plasma and central nervous sites of action and the existence of the active metabolite morphine-6-glucuronide with opioid agonistic effects, Furthermore, there is no well-defined toxic dose or plasma/blood concentration for morphine. Dosing is often adjusted for adequate pain relief. Here, we summarize reported deaths associated with morphine therapy, including associated morphine exposure and modulating patient factors such as pharmacogenetics, concomitant medications, or comorbidities. In addition, we systematically analyzed published numerical information on the stability of concentrations of morphine and its relevant metabolites in biological samples collected postmortem. A medicolegal case is presented in which the causality of morphine administration with death was in dispute and pharmacokinetic modeling was applied to infer the administered dose. The results of this analytical review suggest that (i) inference from postmortem blood concentrations to the morphine dose administered has low validity and (ii) causality between a patient's death and the morphine dose administered remains a highly context-dependent and collaborative assessment among experts from different medical specialties.

Endogenous opioid systems alterations in pain and opioid use disorder

Decades of research advances have established a central role for endogenous opioid systems in regulating reward processing, mood, motivation, learning and memory, gastrointestinal function, and pain relief. Endogenous opioid systems are present ubiquitously throughout the central and peripheral nervous system. They are composed of four families, namely the μ (MOPR), κ (KOPR), δ (DOPR), and nociceptin/orphanin FQ (NOPR) opioid receptors systems. These receptors signal through the action of their endogenous opioid peptides β-endorphins, dynorphins, enkephalins, and nociceptins, respectfully, to maintain homeostasis under normal physiological states. Due to their prominent role in pain regulation, exogenous opioids-primarily targeting the MOPR, have been historically used in medicine as analgesics, but their ability to produce euphoric effects also present high risks for abuse. The ability of pain and opioid use to perturb endogenous opioid system function, particularly within the central nervous system, may increase the likelihood of developing opioid use disorder (OUD). Today, the opioid crisis represents a major social, economic, and public health concern. In this review, we summarize the current state of the literature on the function, expression, pharmacology, and regulation of endogenous opioid systems in pain. Additionally, we discuss the adaptations in the endogenous opioid systems upon use of exogenous opioids which contribute to the development of OUD. Finally, we describe the intricate relationship between pain, endogenous opioid systems, and the proclivity for opioid misuse, as well as potential advances in generating safer and more efficient pain therapies.

Less Well-Known Consequences of the Long-Term Use of Opioid Analgesics: A Comprehensive Literature Review

BACKGROUND

The adverse effects of short-term opioid analgesics are well known and acknowledged; however, the spectrum of the sequelae of long-term use seems less clear. Some effects may remain undetected but still have the potential to cause harm and reduce patients' quality of life.

OBJECTIVE

To review the literature on the adverse effects of long-term opioid therapy.

METHODS

We performed a quasi-systematic search, analyzing articles published in the MEDLINE database between January 2000 and March 2021 that identified adverse effects of opioids used for chronic pain treatment.

RESULTS

Growing evidence indicates that there are multiple serious adverse effects of opioid treatment. Long-term opioid use may have significant effects on the endocrine, immune, cardiovascular, respiratory, gastrointestinal, and neural systems. Studies show that long-term opioid treatment increases the risk of fractures, infections, cardiovascular complications, sleep-disordered breathing, bowel dysfunction, overdose, and mortality. Opioids may potentially affect cancer development. Most consequences of the long-term use of opioids have been identified in studies of patients with non-malignant pain.

CONCLUSION

Studies indicate that long-term use of opioids increases the risk of drug-related events in a significant number of patients. Clinicians should be aware of these complications associated with prescribing opioids, discuss them with patients, prevent complications, if possible, and diagnose them early and manage adequately. More human studies are needed to assess the risk, including trials with individual opioids, because they have different adverse effect profiles.

All-Cause and Overdose Mortality Risk Among People Prescribed Opioids: A Systematic Review and Meta-analysis

OBJECTIVE

To estimate all-cause and overdose crude mortality rates and standardized mortality ratios among people prescribed opioids for chronic noncancer pain and risk of overdose death in this population relative to people with similar clinical profiles but not prescribed opioids.

DESIGN

Systematic review and meta-analysis.

METHODS

Medline, Embase, and PsycINFO were searched in February 2018 and October 2019 for articles published beginning 2009. Due to limitations in published studies, we revised our inclusion criteria to include cohort studies of people prescribed opioids, excluding those studies where people were explicitly prescribed opioids for the treatment of opioid use disorder or acute cancer or palliative pain. We estimated pooled all-cause and overdose crude mortality rates using random effects meta-analysis models. No studies reported standardized mortality ratios or relative risks.

RESULTS

We included 13 cohorts with 6,029,810 participants. The pooled all-cause crude mortality rate, based on 10 cohorts, was 28.8 per 1000 person-years (95% CI = 17.9-46.4), with substantial heterogeneity (I2 = 99.9%). The pooled overdose crude mortality rate, based on six cohorts, was 1.1 per 1000 person-years (95% CI = 0.4-3.4), with substantial heterogeneity (I2 = 99.5%), but indications for opioid prescribing and opioid exposure were poorly ascertained. We were unable to estimate mortality in this population relative to clinically similar populations not prescribed opioids.

CONCLUSIONS

Methodological limitations in the identified literature complicate efforts to determine the overdose mortality risk of people prescribed opioids. There is a need for large-scale clinical trials to assess adverse outcomes in opioid prescribing, especially for chronic noncancer pain.

Both Race and Insurance Type Independently Predict the Selection of Oral Opioids Prescribed to Cancer Outpatients

BACKGROUND

Previous research suggests that racial disparities in patients' reported analgesic adverse effects are partially mediated by the type of opioid prescribed to African Americans despite the presence of certain comorbidities, such as renal disease.

AIMS

We aimed to identify independent predictors of the type of opioid prescribed to cancer outpatients and determine if race and chronic kidney disease independently predict prescription type, adjusting for relevant sociodemographic and clinical confounders.

DESIGN

We conducted a secondary analysis of a 3-month observational study.

SETTING

Outpatient oncology clinics of an academic medical center.

PARTICIPANTS/SUBJECTS

Patients were older than 18 years of age, self-identified as African American or White, and had an analgesic prescription for cancer pain.

METHODS

Cancer patients (N = 241) were recruited from outpatient oncology clinics within a large mid-Atlantic healthcare system.

RESULTS

Consistent with published literature, most patients (75.5%) were prescribed either morphine or oxycodone preparations as oral opioid therapy for cancer pain. When compared with Whites, African Americans were significantly more likely to be prescribed morphine (33% vs 14%) and less likely to be prescribed oxycodone (38% vs 64%) (p < .001). The estimated odds for African Americans to receive morphine were 2.573 times that for Whites (95% confidence interval 1.077-6.134) after controlling for insurance type, income, and pain levels. In addition, the presence of private health insurance was negatively associated with the prescription of morphine and positively associated with prescription of oxycodone in separate multivariable models. The presence of chronic kidney disease did not predict type of analgesic prescribed.

CONCLUSIONS

Both race and insurance type independently predict type of opioid selection for cancer outpatients. Larger clinical studies are needed to fully understand the sources and clinical consequences of racial differences in opioid selection for cancer pain.