July 13, 2007

‘Black box’ labels reducing antidepressant prescriptions

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‘Black box’ labels reducing antidepressant prescriptions

A study by Vanderbilt researchers shows that the addition of “black box” warning labels to antidepressants has led to a decrease in prescription rates and use in children and adolescents.

Most noticeable was the decrease in initial prescribing of antidepressants after the warnings began.

In 2004, “black box” warning labels were placed on all antidepressants by the Food and Drug Administration (FDA) and the United Kingdom's equivalent, the Committee on Safety of Medicines (CSM) after reports of an increase in suicides in children and adolescents who were taking antidepressants.

The study, published in the July issue of Archives of Pediatrics & Adolescent Medicine, was authored by Ben Kurian, M.D., post-doctoral research fellow in the Department of Psychiatry at UT Southwestern Medical Center and former house officer in Psychiatry at Vanderbilt; Wayne Ray, Ph.D., professor of Preventive Medicine; Patrick Arbogast, Ph.D., assistant professor of Biostatistics; Catherine Fuchs, M.D., associate professor of Psychiatry; Judith Dudley, computer systems analyst; and William Cooper, M.D., associate professor of Pediatrics.

The study ran from Jan. 1, 2002, to Sept. 30, 2005, and the population included TennCare enrollees age 2 to 17 who had been in the program for at least one year.

In previous studies, it was shown that TennCare enrollees were similar to the rest of the country in the rates of use of other psychiatric medications.

The study was divided into two periods: the 24 months before the regulatory warnings were included, and the 24 months after the regulatory warnings. An average of 405,000 children and teens qualified for the study each month.

The authors hypothesized that regulatory warnings would have the greatest effect on the decision to begin treatment with an antidepressant. The authors also thought that use might decrease in those already taking antidepressants.

Before the regulatory warnings, there was little variance from month to month in rates of new antidepressant prescriptions, averaging 23 per 10,000 patients.

At the end of the study, that number had dropped to an average of 15 per 10,000 patients, which is an estimated 33 percent decrease.

However, the authors wrote, “There was no evidence of an increase of discontinuations of therapy with antidepressants or other psychotropic drugs, which suggests the primary effect of the warnings was to alter the decision to treat a newly presenting patient.”

“These findings are interesting because studies of previous prescription drug warnings have produced mixed results — many warnings did not result in huge changes,” Cooper said.

“We were surprised with the decrease in the rates of antidepressants being used among children. What we don't know is whether this decrease is desirable or not. It may be that children who are depressed may not be receiving needed medications.

“It's also possible that children who were receiving these medications for marginal indications before aren't receiving them now.

“The study findings highlight the fact that we need better information on the efficacy and safety of these medicines to guide treatment decisions,” Cooper said.