Importance: Benzodiazepines have been a common target for policy interventions to curtail inappropriate use, with mixed results. To reduce alprazolam misuse, in February 2017, Australia delisted the 2-mg tablet strength from public subsidy, eliminated refills, and reduced the pack size from 50 tablets to 10 tablets.

Objective: To describe changes in alprazolam dispensing, prescribing, and poisonings associated with the implementation of a new policy to reduce inappropriate prescription of alprazolam in Australia.

Design, Setting, and Participants: This interrupted time series analysis and cross-sectional study included data from a 10% sample of Australian people who received publicly subsidized dispensing claims and prescribing approvals for alprazolam from January 1, 2015, to December 31, 2018, and all calls to a poison information service involving alprazolam from February 1, 2015, to October 31, 2018. Autoregressive error models were used to quantify changes over time and compare patterns of use before and after the intervention. Data analyses were conducted from November 2018 to May 2019.

Exposure: Implementation of the policy change on February 1, 2017.

Main Outcomes and Measures: Monthly trends in alprazolam prescribing approvals and dispensings, quarterly trends in telephone calls involving alprazolam to a poison information service, and patterns of prescribing and dispensing before and after the intervention.

Results: From 2015 to 2018, there were 71 481 alprazolam dispensings to 6772 people. After the intervention, overall dispensing decreased by 51.2% (95% CI, 50.5%-51.9%) and prescribing approvals increased by 17.5% (95% CI, 13.0%-22.2%). Overall, the proportion of dispensing of packs of 51 to 100 tablets increased from 5776 of 24 282 dispensings (23.8%) to 4888 of 10 676 dispensings (45.8%) (risk difference [RD], 22.0% [95% CI, 19.4%-24.6%]) and dispensing of packs of more than 100 tablets increased from 1029 of 24 282 dispensings (4.2%) to 1774 of 10 676 dispensings (16.6%) (RD, 12.4% [95% CI, 10.6%-14.2%]). Among people receiving their first alprazolam prescription, initiation with packs of 10 tablets or fewer increased from 16 of 1127 people (1.4%) before the intervention to 139 of 589 people (23.6%) after the intervention (RD, 22.2% [95% CI, 18.7%-25.7%]). Alprazolam treatment initiation with packs of more than 50 tablets also increased from 63 of 1127 people (5.6%) before the intervention to 144 of 589 people (24.4%) after the intervention (RD, 18.9% [95% CI, 15.1%-22.6%]). During 1 year before the intervention, patients received a median (interquartile range [IQR]) total of 250 (50-600) tablets and median (IQR) total combined tablet strength of 188 (50-550) mg. During 1 year after the intervention, people were dispensed less alprazolam, with a median (IQR) total of 200 (50-500) tablets and median (IQR) total combined tablet strength of 120 (30-360) mg. There was little change in poisoning calls involving alprazolam.

Conclusions and Relevance: This study found that after the policy intervention, subsidized alprazolam use decreased, but the increase in prescribing approvals placed additional burden on prescribers. Even after the intervention, most people who were dispensed alprazolam were still receiving treatment contrary to best-practice recommendations. Furthermore, the poison information center data suggested that people were still being dispensed the 2-mg tablet strength, presumably as nonsubsidized (ie, private) prescriptions.