The study, led by Colin Dormuth, an assistant professor in the Department of Anesthesiology, Pharmacology and Therapeutics, found that PharmaNet, a real-time prescription system implemented in B.C. pharmacies in 1995, reduced potentially inappropriate prescriptions for opioids and benzodiazepines in two groups of patients — those on social assistance and seniors. The reductions ranged from about one-third to one-half depending on the drug and patient group.
The findings are reported in a study in CMAJ (Canadian Medical Association Journal).
Benzodiazepines and opioid analgesics are prescription medications that are prone to misuse and addiction in some patients. Benzodiazepines include sedatives and anti-anxiety drugs such as diazepam, lorazepam and others, whereas opioids are taken for pain relief and include morphine, codeine, oxycodone and other drugs.
The PharmaNet system allows B.C. pharmacists to view the most recent 14 months of a patient’s medication use regardless of which physician prescribed the drugs or which pharmacy dispensed them. The system enables pharmacists to identify potentially harmful drug interactions, accidental duplications in therapy or potential prescription drug misuse.
“Our study demonstrates that a system like PharmaNet can help reduce the potentially inappropriate prescribing of medications that are prone to misuse,” said Dormuth, a member of UBC’s Therapeutics Initiative. “If our findings can be extrapolated to the rest of Canada and the U.S., such systems could eliminate millions of inappropriate prescriptions every year.”
BACKGROUND | Centralized prescription networks
Medication databases: Most provinces have now adopted either a system allowing the pharmacist to view a patient’s up-to-date medication history at the time of dispensing a medication or a real-time monitoring program specifically aimed at prescription drugs prone to misuse. Ontario adopted the latter approach in establishing its Narcotics Monitoring System earlier this year.
Study design: Researchers tracked “potentially inappropriate” prescriptions for opioids and benzodiazepines in BC, defined as a second prescription for the same drug issued by a different doctor and a different pharmacy within seven days of a previous prescription for at least 30 tablets. The study covered the years 1993 to 1997 – a 5-year period including the program’s implementation. Because comprehensive data was available for people aged 65 years and over and patients receiving social assistance, the study focused on these two groups of patients.
Funding: The study was co-funded by grants from the Canadian Institutes of Health Research and the B.C. Ministry of Health. The research was conducted by the Canadian Drug Safety and Effectiveness Research Network – an interprovincial collaboration of drug safety researchers in British Columbia, Manitoba, Ontario and Quebec.