ABSTRACT FROM: Hampton LM, Daubresse M, Chang HY, et al. Emergency department visits by adults for psychiatric medication adverse events. JAMA Psychiatry 2014;71:1006–14.
More than 1 in 10 adults in the USA use psychiatric medications to treat mental illness. Data are lacking on the prevalence of adverse drug events (ADEs) resulting from therapeutic use of psychiatric medications when used outside of strictly controlled clinical trials. As an interface between hospitals and communities, emergency departments (EDs) represent an ideal place to identify and characterise ADEs occurring in the general population.
The authors reviewed and analysed medical records from national probability samples of ED and outpatient visits by adults 19 years or older, from 2009 to 2011. Data were extracted from three US population-representative public health surveillance databases, including the National Electronic Injury Surveillance System-Cooperative Adverse Drug Event Surveillance (NEISS-CADES) project, based on data collected from a nationally representative sample of US hospital EDs. Sedatives and anxiolytics, antidepressants, antipsychotics, lithium salts and stimulants were considered as psychiatric medications in this study. A case was defined as an ED visit for an ADE, categorised as adverse reactions, allergic reactions, secondary effects and unintentional therapeutic overdoses. Intentional self-harm, documented drug abuse, therapeutic failures, and non-adherence or drug withdrawal were excluded from this definition. Each of the 4048 identified cases of ED visit for a psychiatric medication ADE received a sample weight based on the inverse probability of selection. National estimates were calculated accounting for the sample weights and complex sample designs. The main outcomes were: (1) the national estimate of ADE ED visits resulting from therapeutic psychiatric medication use and (2) the national estimate of psychiatric medication ADE ED visits per 10 000 outpatient visits at which psychiatric medications were prescribed.
This is the first analysis, to date, of ADE ED visits resulting from psychiatric medication use. These results are of high interest because they come from a representative sample of the US general population of patients under psychopharmacological treatment.
ED visits due to ADEs from therapeutic use of psychiatric medications accounted for almost 1 in 10 adult ADE ED visits (9.6%, 95% CI 8.3% to 11.0%). Almost half of these ADEs involved patients aged 19–44 years (49.4%, 46.5 to 52.4%), and 1 in 5 resulted in hospitalisation (19.3%, 16.3 to 22.2%).
Antipsychotics (especially haloperidol) and lithium salts were implicated in more than one ADE ED visit per 1000 outpatient prescription visits (11.7 and 16.4 per 10 000, respectively). Antipsychotics and antidepressants were the leading cause of psychiatric medication ADE ED visits by patients aged 19–44 years (31.3% (27.6 to 35.0%) and 30.5% (27.8 to 33.2%), respectively), whereas zolpidem alone accounted for more than one in five visits by patients aged 65 years or older (21.0%, 16.3 to 25.7%).
The findings are limited to the subgroups of patients seeking care in EDs and of ADEs that can be readily identified in the ED context. Chronic adverse effects (eg, metabolic disorders associated with antipsychotics) are also unlikely to have been identified in this setting where patients present for attention to an emergency medical condition.
The definition of ADEs excluded substantial public health concerns such as medical abuse or use for self-harm, and also excluded medication underuse (non-adherence or drug withdrawal). This limited definition may have led to underestimation of the ADE burden from therapeutic use of psychiatric medications.
The study did not collect information on psychiatric medication dosage or indication, which may limit the accuracy of the estimates.
Data obtained from continued public health surveillance such as the NEISS-CADES project should be used to assess the positive or negative impact of DSM-5 implementation on how psychiatric medication ADE rates will change in the future.1
Focused research on age-related differences in ADEs is needed to identify the specific causes of younger adults’ high rates of psychiatric medication ADE ED visits, investigating factors such as number of comorbidities, socioeconomic status, psychiatric medication dosage or time from treatment initiation to ADE onset.
Yes. Considering the growing exposition to antipsychotics in the general population and the increasing off-label use of antipsychotics,2 ,3 the findings of this study urge providers to prescribe antipsychotics cautiously and only after exploring the feasibility of using alternative treatments. In the same manner, these results should incite providers to take a critical look at the trend in prescribing Z-drugs4 and to only prescribe the latter after considering non-pharmacological measures to manage insomnia, especially in adults 65 years of age or older. The prescription of antidepressants, antipsychotics, sedatives and anxiolytics among younger adults should not be trivialised. In conclusion, this study provides strong evidence data to balance the current process of medicalisation of psychopathology under both patient and society pressure.
Competing interests: None declared.
Batstra L, Frances A. Holding the line against diagnostic inflation in psychiatry. Psychother Psychosom 2012; 81:5–10. Verdoux H, Tournier M, Bégaud B, et al. Antipsychotic prescribing trends: a review of pharmaco-epidemiological studies. Acta Psychiatr Scand 2010; 121:4–10. Alexander GC, Gallagher SA, Mascola A, et al. Increasing off-label use of antipsychotic medications in the United States, 1995–2008. Pharmacoepidemiol Drug Saf 2011; 20:177–84. What's wrong with prescribing hypnotics? Drug Ther Bull 2004; 42:89–93. 
