# Patterns and trajectories associated with overdose in patients co-prescribed opioids and benzodiazepines

> **NIH ALLCDC R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2023 · $350,000

## Abstract

PROJECT SUMMARY
Despite prevention efforts and reduced opioid prescribing, U.S. overdose rates continue to rise. Millions of
patients prescribed opioids for chronic pain are co-prescribed benzodiazepines, which heighten overdose
risk. However, tapering either opioids or benzodiazepines may also increase overdose and mental health
risks, and clinicians lack evidence-based guidance about how to safely reduce risk in patients who are co-
prescribed opioids with benzodiazepines. Rates of fatal and non-fatal overdose involving prescribed opioids
or benzodiazepines combined with illicit opioids or psychostimulants are also rapidly increasing. The specific
aims of this proposed study are: Aim 1) To identify risk and protective factors, prescribing patterns, and
trajectories associated with progression to long-term benzodiazepine use among patients prescribed long-
term opioids. This aim addresses root causes of long-term opioid-benzodiazepine co-prescription. Aim 2) To
identify risk and protective factors, prescribing patterns, and trajectories associated with overdose involving
prescription opioids or benzodiazepines among patients co-prescribed long-term opioids and
benzodiazepines. Findings from this Aim will inform prescription overdose prevention efforts in the large
population of patients who are co-prescribed opioids and benzodiazepines. Aim 3) To identify risk and
protective factors, prescribing patterns, and trajectories associated with overdose involving either illicit
opioids or psychostimulants among patients co-prescribed long-term opioids and benzodiazepines. This Aim
will identify factors that may prevent the progression from long-term use of prescribed opioids and
benzodiazepines to use of illicit opioids or stimulants. We will accomplish these aims by conducting
retrospective cohort studies using two large, complementary data sources: 1) the California Prescription
Drug Monitoring Program (PDMP) data linked to death certificates, and 2) the OptumLabs Data Warehouse,
a national claims data source representing over 20% of the U.S. commercial and Medicare Advantage
market. As the PDMP are linked to death records, the California statewide analyses will focus on fatal
overdoses, while the OptumLabs claims analyses will focus on non-fatal overdoses. By capitalizing on the
statistical power achieved by these large data sources, this project will elucidate risk and protective factors,
drug-use patterns, and trajectories associated with initiation of benzodiazepines among patients prescribed
long-term opioids and will identify factors associated with risk of overdose from prescribed opioids,
benzodiazepines, or illicit opioids or psychostimulants. Findings will richly inform clinical or policy
interventions and guidelines to prevent initial benzodiazepine-opioid co-prescribing and to mitigate overdose
risk in patients with established co-prescriptions.

## Key facts

- **NIH application ID:** 10708121
- **Project number:** 5R01CE003468-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Joshua J Fenton
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** ALLCDC
- **Fiscal year:** 2023
- **Award amount:** $350,000
- **Award type:** 5
- **Project period:** 2022-09-30 → 2025-09-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10708121

## Citation

> US National Institutes of Health, RePORTER application 10708121, Patterns and trajectories associated with overdose in patients co-prescribed opioids and benzodiazepines (5R01CE003468-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10708121. Licensed CC0.

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