Impact of a US Food and Drug Administration Drug Safety Communication on Zolpidem Dosing: An Observational Retrospective Cohort.

Abstract

Zolpidem is a sedative-hypnotic widely prescribed in the United States. Recently, the US Food and Drug Administration (FDA) issued a drug safety communication regarding its dosing in women. To compare compliance with FDA-approved dosing for zolpidem in women before and after a drug safety communication, and to evaluate compliance based on pharmacy location and prescriber type. This was a retrospective, observational cohort study. New prescriptions for Ambien, Ambien CR, Edluar, or Zolpimist or their respective generics dispensed from Kerr Drug pharmacies in North Carolina to women 18-64 years of age between April and September of 2012 ("before" cohort) or April and September of 2013 ("after" cohort) were included. χ(2) tests were conducted to assess overall compliance, as well as compliance based on location (urban or rural) and prescriber type (physician or midlevel), with FDA-approved dosing for zolpidem. Trends in total prescription volume and total zolpidem prescription volume for all Kerr Drug pharmacies over the study period were also described. A total of 14,156 prescriptions for zolpidem were included in the primary analysis. Sixteen percent of prescriptions dispensed were in compliance with FDA recommendations following the FDA alert. A statistically significant increase was observed in compliance with FDA-approved dosing for zolpidem (odds ratio = 1.49; 95% CI, 1.35-1.65; P < .0001) postdrug safety communication. Significant increases in compliance were also observed in the post-FDA communication subgroups based on location and prescriber type, though no subgroup was found to be significantly more compliant than another. The release of a drug safety communication by the FDA resulted in a statistically significant increase in proper dosing of zolpidem in women. Further research is needed in order to determine the impact of FDA alerts on prescribing patterns and the reasons for therapeutic substitution after such alerts.