Kelly is the director of the Treatment Research Program at the Maryland Psychiatric Research Center (pictured left), and Vyas is a psychiatrist at the Treatment Research Center. They spoke yesterday at APA’s IPS: The Mental Health Services Conference in Chicago.
Clozapine has been shown repeatedly to be the best medication for treatment-resistant schizophrenia. Yet Kelly and Vyas explained that African Americans with schizophrenia are much less likely to receive clozapine and more likely to have the medication discontinued because of neutropenia, or low white blood cell counts. Clozapine is known to increase the risk for agranulocytosis—a condition of extremely low white blood cell counts that can be life threatening—and patients using clozapine are required to undergo periodic blood monitoring. Many African-American patients who never received the drug or were taken off it, however, may have benign ethnic neutropenia (BEN), a condition that occurs in about 25% to 50% of people of African ancestry and up to 38% of people of Middle-Eastern descent.
Kelly and Vyas said that the standards for determining when a patient has neutropenia have largely been drawn from European Caucasian populations.For instance, up until 2015, the Food and Drug Administration required clozapine to be discontinued when neutrophil counts fell below 1500/uL. But individuals with BEN are liable to have naturally occurring neutrophil counts that fall below that standard and are not at greater risk of agranulocytosis.
In 2015, the FDA lowered the threshold for interrupting clozapine treatment from an absolute neutrophil count of 1,500/uL to 1,000/uL. New guidelines have been issued for patients believed to have BEN, which are intended to make it easier to prescribe and continue clozapine use for these patients.
“Clozapine is underutilized due to many reasons, and its use in African-descent patients is very low,” Kelly said. “The underuse most likely is attributed to BEN, but clozapine use in BEN does not increase the risk for agranulocytosis or infection related to using clozapine.”
For related information see the Psychiatric News article “New Clozapine Guidelines Likely to Limit Treatment Interruptions.”
(Image: Mark Moran)