Antipsychotics: Adverse Events That Send Patients to the ED

Lee Hampton, MD, MSc


July 10, 2014

Editorial Collaboration

Medscape &

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Hello. I'm Dr. Lee Hampton, a medical officer working on the detection and prevention of adverse drug events at the Centers for Disease Control and Prevention (CDC). I'm pleased to speak with you as part of the CDC Expert Commentary series on Medscape.

In 2013, the American Psychiatric Association (APA) advised clinicians to carefully evaluate patients before prescribing antipsychotics to ensure that the antipsychotics were clinically warranted.[1] As Dr. Joel Yager, Chair of the APA's Council on Quality Care, said, "Antipsychotic medications have tremendous benefits and improve the quality of life for many people with serious mental illness, however, they carry risks including potentially harmful side effects."[2]

CDC recently completed a study estimating how many adult emergency department (ED) visits are made each year in the United States because of adverse events from such antipsychotics as haloperidol, quetiapine, and risperidone.[3] Using data from reviews of the medical records of all ED visits made in 2009, 2010, and 2011 at 63 randomly selected US hospitals, we estimated that adverse events from antipsychotics cause more than 20,000 visits to EDs each year.

Relative to the number of outpatient visits at which these drugs were prescribed, antipsychotics as a class caused more than 3 times more ED visits for adverse drug events than sedatives and anxiolytics, 4 times more ED visits than stimulants, and almost 5 times more ED visits than antidepressants. Movement disorders, such as dystonia, extrapyramidal disorders, and trismus, were the most common problems that prompted patients to visit an ED for an antipsychotic adverse event. These results support recommendations that antipsychotics should be prescribed with caution,[1] especially because this study looked only at problems leading to ED visits and did not address chronic metabolic problems with which antipsychotics have been associated, such as diabetes.[1,4]

We also found that haloperidol caused almost 4 times more ED visits for adverse drug events than antipsychotics as a group, relative to the number of outpatient visits at which these drugs were prescribed. Haloperidol caused more than 5 times more movement disorders than other typical antipsychotics, and more than 13 times more movement disorders than atypical antipsychotics, relative to the number of outpatient visits at which they were prescribed. These findings suggest that haloperidol should be prescribed with particular caution.

Using alternative treatments instead of antipsychotic drugs can be an effective way of avoiding antipsychotic adverse events. Avoiding antipsychotics in favor of other options that are less likely to cause adverse events may be particularly appropriate when considering treatment of such conditions as major depressive disorder, insomnia, and anxiety disorders. The US Food and Drug Administration (FDA) has not approved the use of any antipsychotic for the first-line treatment of major depressive disorder or insomnia, or any atypical antipsychotic for the first-line treatment of anxiety disorders.[5]

Lee Hampton, MD, MSc, is a medical officer with the Division of Healthcare Quality Promotion, where he works on the detection and prevention of adverse drug events. He first joined CDC as Epidemic Intelligence Service Officer assigned to the Respiratory Diseases Branch of the Division of Bacterial Diseases. Dr. Hampton received his medical degree from the University of North Carolina-Chapel Hill and completed specialty training in pediatrics at Yale-New Haven Hospital. He is also Adjunct Assistant Professor of Pediatrics at the Emory University School of Medicine.