Inpatient Z-drug use commonly exceeds safe dosing recommendations

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.

Retrospective cohort study.

McGill University Health Centre, an 832-bed tertiary care institution in Montréal, Canada.

All adult non-obstetrical patients admitted between April 1, 2015 and March 31, 2016.

The receipt of at least one dose of Z-drug as determined by pharmacy records.

Adherence to four recommendations related to starting dose, maximal dose, concomitant drug administration, and duration of use were evaluated.

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.

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.