# Psychoactive prescription drug use and misuse in patients on opioid agonist treatment

## TL;DR

This study examines how patients on opioid treatment use and misuse prescription drugs, finding that opioids and pregabalin are commonly misused.

## Contribution

The study identifies specific prescription drugs disproportionately misused and tracks their misuse trends over time in opioid-treated patients.

## Key findings

- Morphine, methylphenidate, oxycodone, clonazepam, and fentanyl were disproportionately misused, particularly via diverted administration.
- Pregabalin misuse increased sharply by 2366% from 2014 to 2023, while morphine's illegal acquisition decreased by 59%.
- Improving access to naloxone is recommended to address the risk of opioid overdose.

## Abstract

To identify the patterns and trends in prescription drug use and misuse in patients on opioid agonist treatment.

We used data from the OPPIDUM programme, which collects data from patients attending substance abuse treatment facilities. Data collected include use of psychoactive prescription drugs in the past week. In this cross‐sectional study, we included patients aged at least 18 years, on opioid agonist treatment and reporting psychoactive prescription drug use in the past week from 2014 to 2023. The outcome was psychoactive prescription drug misuse (i.e., abuse and/or dependence, illegal acquisition and diverted route of administration) in the past week. We conducted disproportionality analyses to identify prescription drugs associated with misuse. We calculated the prevalence of use and misuse for each prescription drug to estimate trends.

We included 9631 patients. Misuse was disproportionately reported for morphine (e.g., diverted route of administration: n = 580; reporting odds ratio: 224.4 [95% confidence interval: 178.8, 281.7]), methylphenidate (e.g., diverted route of administration: 149; 31.6 [24.1, 41.4]), oxycodone (e.g., diverted route of administration: 24; 20.2 [11.1, 36.8]), clonazepam (e.g., illegal acquisition: 48; 6.0 [4.0, 9.0]) and fentanyl (e.g., diverted route of administration: 6; 5.8 [2.3, 14.8]). Trends in misuse paralleled trends in use for most prescription drugs. The sharpest increase in misuse included abuse and/or dependence (+2366%, from 0.9 per 1000 patients in 2014 to 23.0 per 1000 patients in 2023) for pregabalin. Conversely, the sharpest decrease in misuse included illegal acquisition (−59%, from 82.1 per 1000 patients in 2014 to 33.9 per 1000 patients in 2023) for morphine.

In this population, prescription drug misuse primarily included opioid analgesics and increasingly pregabalin. Given the risk of opioid overdose, access to take‐home naloxone should be further improved.