Effect of a centralized prescription network on inappropriate prescriptions for opioid analgesics and benzodiazepines

Background: Opioid analgesics and benzo diazepines are often misused in clinical practice. We determined whether implementation of a centralized prescription network offering real-time access to patient-level data on filled prescriptions (PharmaNet) reduced the number of potentially inappropriate prescriptions for opioids and benzodiazepines. Methods: We conducted a time series analysis using prescription records between Jan. 1, 1993, and Dec. 31, 1997, for residents of the province of British Columbia who were receiving social assistance or were 65 years or older. We calculated monthly percentages of filled prescriptions for an opioid or a benzodiazepine that were deemed inappropriate (those issued by a different physician and dispensed at a different pharmacy within 7 days after a filled prescription of at least 30 tablets of the same drug). Results: Within 6 months after implementation of PharmaNet in July 1995, we observed a relative reduction in inappropriate filled prescriptions for opioids of 32.8% (95% confidence interval [CI] 31.0%-34.7%) among patients receiving social assistance; inappropriate filled prescriptions for benzodiazepines decreased by 48.6% (95% CI 43.2%-53.1%). Similar and statistically significant reductions were observed among residents 65 years or older. Interpretation: The implementation of a centralized prescription network was associated with a dramatic reduction in inappropriate filled prescriptions for opioids and benzodiazepines.