# Beyond Addiction: Burden of Polypharmacy and Risk in Frail Patients with Substance Use Disorder

## TL;DR

This study examines the high use of multiple medications in patients with substance use disorder and highlights the need for better drug management to improve treatment safety.

## Contribution

The study provides new insights into polypharmacy patterns and risks in frail patients with substance use disorder.

## Key findings

- 37.2% of patients with SUD used 2–5 medications, and 8.1% used 6–10 medications.
- Women had a higher rate of significant polypharmacy (3.5%) compared to men (1.1%).
- Therapeutic duplication was common, especially for psycholeptics and psychoanaleptics.

## Abstract

Substance use disorder (SUD) is a chronic and clinically complex condition, frequently complicated by significant organic and psychiatric comorbidities. Most patients are polymedicated and require opioid substitution programs (OSPs). This complexity is further exacerbated by drug–drug interactions, therapeutic duplication, and fragmentation of the healthcare system. This retrospective observational study analyses the prevalence of polypharmacy and associated pharmacotherapeutic risks in a cohort of 1050 patients with SUD treated at Drug Care Units (DCUs) in Tenerife (Canary Islands, Spain). Prescriptions were dominated by methadone (62%), antidepressants, and antipsychotics, often in combination with benzodiazepines. Significant polypharmacy (>10 active prescriptions) was observed in 2.3% of patients, while 8.1% received 6–10 medications and 37.2% were using 2–5 medications. Women showed a higher pharmacological burden, with 3.5% experiencing significant polypharmacy (>10 different prescriptions) compared with 1.1% of men. Overall, 31% of patients received antidepressants, 31% were treated with antipsychotics—frequently with concurrent use of multiple agents—and 6.4% received opioids outside the OSP. Therapeutic duplication was observed in 15.6% of patients for psycholeptics, 14.2% for psychoanaleptics, and 3.2% for antiepileptics. Additionally, 25.2% of patients reported self-medication, predominantly with benzodiazepines. These findings underscore the need for integrated pharmaceutical care programs incorporating individualized therapeutic review and deprescribing strategies to enhance the safety and efficacy of SUD treatment.