Drug Utilization Pharmacist & Pharmacy Research Coordinator Nova Scotia Health Halifax, Canada
Background: There is evidence of increased risk of overdose and other adverse outcomes when opioids and benzodiazepines (BZD) are administered together. Opioid clinical practice guidelines recommend avoiding concomitant prescribing of opioids and BZD to reduce opioid-related harms.
Objectives: To examine concomitant benzodiazepine prescribing in patients also prescribed chronic opioid therapy (COT) using electronic medical record (EMR) data.
Methods: EMR data of participating primary care providers of the Canadian Primary Care Sentinel Surveillance Network in Nova Scotia, Canada were extracted for each year from 2011-2018. Included patients were ≥18 years old and had visited primary care in the past two years without a cancer or palliative care diagnosis. COT was defined as opioid therapy prescribed for a total duration of ≥84 days (12 weeks). Concomitant therapy was defined as at least one BZD or Z-drug (e.g., zopiclone) prescription at any time in the same year for patients prescribed COT. Trends were analyzed using the Cochran-Armitage test.
Results: Separate patient cohorts for each year (mean 44,553 patients/year) that met inclusion criteria were created from EMR data. COT prescribing alone was stable from 2011 to 2018, ranging from 2.5% (2011: 1016/41,211) of patients to 2.6% (2018: 1152/44,880) of patients (p=0.994). Prescribing of at least one BZD/Z-drug prescription increased from 11.7% (2011: 4831/41,211) to 13.0% (2018: 5840/44,880) in the entire cohort (p < 0.0001). Concomitant prescribing of BZD/Z-drug remained stable at 38.7% (2011: 393/1016) and 37.6% (2018: 433/1152) of patients prescribed COT (p=0.874). In 2018, the top three prescribed BZD/Z-drugs in patients prescribed COT were zopiclone (40.2%, 174/433), lorazepam (39.3%, 170/433) and clonazepam (20.1%, 87/433).
Conclusions: Almost 40% of patients prescribed COT were also prescribed at least one prescription for BZD or Z-drug, despite the known potential harms. Prescribing data can help primary care providers identify high-risk patients for future interventions and result in safer care for patients.
