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Impact of the COVID-19 Controlled Drugs and Substances Act exemption on pharmacist prescribing of opioids, benzodiazepines and stimulants in Ontario: a cross-sectional time-series analysis


Background — Due to the coronavirus disease 2019 (COVID-19) pandemic, Health Canada issued an exemption to the Controlled Drugs and Substances Act (CDSA) on March 19, 2020, enabling pharmacists to act as prescribers of controlled substances to support continuity of care. Our study investigates utilization of the CDSA exemption by Ontario pharmacists with the intent to inform policy on pharmacist scope of practice and to improve future patient outcomes.

Methods — We conducted a time-series analysis of pharmacist-prescribed opioid, benzodiazepine and stimulant claims data using Ontario Narcotics Monitoring System (NMS) data between January 2019 and December 2021. We used ARIMA modelling to measure the change to these classes of claims and to opioid claims containing quantities greater than a 30-day supply.

Results — Postexemption, the average weekly number of pharmacist-prescribed opioid, benzodiazepine and stimulant claims rose by 146% (160 to 393 claims/week), 960% (49 to 515 claims/week) and 2150% (8 to 177 claims/week), respectively. There was a 2-week lag period between the time of announcement and the statistically significant increase in claims on April 5, 2020(p < 0.0001). The total number of claims for opioid quantities exceeding a 30-day supply decreased by 60%. Cumulative pharmacist-prescribed claims accounted for under 2% of the total NMS claims.

Interpretation — Ontario pharmacists used the CDSA exemption but were prescribing at low rates. These findings suggest an effective change to pharmacy practice as the low rates show pharmacists used the exemption as a last line of defense. This may lead to further studies exploring treatment breaks during the COVID-19 pandemic and future changes to pharmacist scope to benefit patients.



Chang A, Chaudhry S, McCormack D, Gomes T, Shivji A, Tadrous M. Can Pharm J (Ott). 2022; Oct 12 [Epub ahead of print].

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