Patients using clozapine for at least a year were not more likely to experience severe neutropenia or to discontinue the medication during the COVID-19 pandemic, when laboratory monitoring became less frequent, according to a report in Psychiatric Services.
Early in the pandemic, the Food and Drug Administration (FDA) removed penalties against health care professionals who were unable to meet the stringent laboratory monitoring requirements for clozapine. Then, in May 2020, an expert workgroup released a consensus statement suggesting that the frequency of monitoring could be reduced from every month to every three months for patients on continuous clozapine treatment for at least one year and no history of neutropenia.
(The FDA recently eliminated their requirements for clozapine prescribing but still recommend that clinicians monitor neutrophil levels according to prescribing information.)
Allison L. Little, Pharm.D., of the Corporal Michael J. Crescenz Department of Veterans Affairs (VA) Medical Center in Philadelphia, and colleagues analyzed data on 2,106 patients in the Veterans Health Administration who had been using clozapine for at least 12 months prior to March 2020; the study period was from March 1, 2020, to July 31, 2021. Clozapine discontinuation was determined to have occurred if the most recent clozapine prescription was coded as “discontinued” and no active prescriptions were listed in the medical record.
Little and colleagues also classified patients according to neutropenia status, with severe neutropenia defined as an absolute neutrophil count (ANC) of less than 500/μL. They further classified patients according to the length of their longest interval between laboratory monitoring: less than 30 days, 31 to 55 days, 56 to 90 days, 91 to 179 days, and greater than180 days.
On average, the longest ANC monitoring gap was 87.8 days, consistent with the consensus statement. No patients discontinued clozapine because of severe neutropenia. In fact, only one patient developed severe neutropenia, and after cessation and careful monitoring, that patient began a new trial of clozapine.
Moreover, the researchers found that longer intervals between ANC monitoring did not increase the rate of clozapine discontinuation. Overall, clozapine discontinuation for any reason occurred in 96 patients.
“More studies are needed to confirm the noninferiority of extended-interval laboratory monitoring for patients receiving clozapine,” the researchers wrote, but added that mental health providers should “consider these results to help bolster prescribing of this highly effective yet underutilized treatment option.”
For related information, see the Psychiatric News article “FDA Has Ended the Clozapine REMS. What Happens Now?”
(Image: Getty Images/iStock/Bacsica)
Don't miss out! To learn about newly posted articles in Psychiatric News, please sign up here.