Spontaneous Adverse Event Reports Associated with Zolpidem in the United States 2003-2012

Stimulated reporting occurs when patients and healthcare professionals are influenced or "stimulated" by media publicity to report specific drug-related adverse reactions, significantly biasing pharmacovigilance analyses. Among countries where the non-benzodiazepine hypnotic drug zolpidem is marketed, the United States experienced a comparable surge of media reporting during 2006-2009 linking the above drug with the development of complex neuropsychiatric sleep-related behaviors. However, the effect of this stimulated reporting in the United States Food and Drug Administration Adverse Event Reporting System has not been explored.

Using disproportionality analyses, reporting odds ratios for zolpidem exposure and the following adverse events; parasomnia, movement-based parasomnia, nonmovement-based parasomnia, amnesia, hallucination, and suicidality were determined and compared to all other medications in the database, followed by specific comparison to the benzodiazepine hypnotic class, year-by-year from 2003 to 2012.

Odds ratios were increased significantly during and after the period of media publicity for parasomnias, movement-based parasomnias, amnesias and hallucinations. We also observed that zolpidem adverse drug reaction (ADR) reports have higher odds for parasomnias, movement-based parasomnias, amnesias, hallucinations, and suicidality compared to all other drugs, even before the media publicity cluster.

Although our results indicate that zolpidem reports have higher odds for the ADR of interest even before the media publicity cluster, negative media coverage greatly exacerbated the reporting of these adverse reactions. The effect of such reporting must be borne in mind when decisions around drugs which have been the subject of intense media publicity are made by health professionals or regulatory bodies.