Inpatient Z-drug use commonly exceeds safe dosing recommendations

Abstract

Importance: In 2016 recommendations for safer prescribing practices were circulated to all doctors in one of Canada's largest provinces, by the college of physicians, following a coroner's inquest into a vehicular death related to Z-drug use. We sought to determine how frequently Z-drug prescriptions in our institution were not adhering to these recommendations. Design: Retrospective cohort study. Setting: McGill University Health Centre, an 832-bed tertiary care institution in Montréal, Canada. Participants: All adult non-obstetrical patients admitted between April 1, 2015 and March 31, 2016. Exposure: The receipt of at least one dose of Z-drug as determined by pharmacy records. Main outcomes and measures: Adherence to four recommendations related to starting dose, maximal dose, concomitant drug administration, and duration of use were evaluated. Results: 1,409 unique patients received a Z-drug during 1,783 admissions representing use in 9.3% of non-obstetrical patients. Standing orders were seen in 42% (745/1783) of admissions. Non-conformity with the coroner's recommendations was common. Overall, 672/1783 (38%) admissions involved a patient receiving more than the recommended daily maximum dose (643/999 older patients, 64%). Of 607 admissions which were longer than 10 days, 257 (39%) involved a prescription which exceeded 10 days. Conclusions and relevance: A coroner's recommendation that doctors receive instructions about safe Z-drug prescribing is unprecedented, and was likely required given that use of Z-drugs occurs at doses and durations that often exceed best practice recommendations. Similar interventions may be required in other jurisdictions.