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  1. Postmarket Drug Safety Information for Patients and Providers

Information on Clozapine

Latest Update

February 24, 2025 - Beginning today, FDA does not expect prescribers, pharmacies, and patients to participate in the risk evaluation and mitigation strategies (REMS) program for clozapine or to report results of absolute neutrophil count (ANC) blood tests before pharmacies dispense clozapine. FDA still recommends that prescribers monitor patients’ ANC according to the monitoring frequencies described in the prescribing information. Information about severe neutropenia will remain in the prescribing information for all clozapine medicines, including in the existing Boxed Warnings.    

Although the risk of severe neutropenia with clozapine still exists, FDA has determined that the REMS program for clozapine is no longer necessary to ensure the benefits of the medicine outweigh that risk. Eliminating the REMS is expected to decrease the burden on the health care delivery system and improve access to clozapine. FDA has notified the manufacturers that the clozapine REMS must be eliminated. FDA has instructed the clozapine manufacturers to formally submit a modification to eliminate the Clozapine REMS and to update the prescribing information, including removing mandatory reporting of ANC blood tests to the REMS program.  

In the coming months, FDA will work with the clozapine manufacturers to update the prescribing information and eliminate the Clozapine REMS. 

Past Updates on Clozapine

Clozapine Risk Evaluation and Mitigation Strategy (REMS) Advisory Committee Meeting 2024

August 9, 2024 - FDA will be hosting an in-person advisory committee meeting on November 19, 2024, to discuss reevaluation of the Clozapine risk evaluation and mitigation strategy (REMS). FDA looks forward to the committee’s advice regarding possible changes to the Clozapine REMS to minimize burden on patients, pharmacies, and prescribers while maintaining safe use of clozapine. Background information, links to webcasts, and instructions on presenting or attending the meeting can be found at the meeting announcement.  

September 21, 2023 - As part of our regular review of all risk evaluation and mitigation strategies (REMS), and in light of the Agency’s continued exercise of enforcement discretion with respect to certain aspects of the Clozapine REMS, FDA is conducting a thorough reevaluation of the Clozapine REMS to determine whether the REMS can be modified to minimize burden on patients, pharmacies, and prescribers while maintaining safe use of clozapine.

As part of this reevaluation, FDA has funded a study by Brigham and Women’s Hospital that includes an analysis of clozapine utilization, adherence to the REMS requirement for monitoring of absolute neutrophil count (ANC), and clinical outcomes. In addition, FDA is conducting a study in collaboration with the Veterans Health Administration to better understand the incidence and severity of neutropenia in patients taking clozapine, and the Agency is conducting a study using the Sentinel System to better understand adherence to the monitoring requirements. All three studies are currently ongoing, and we expect the findings from these studies to be complete within the next year. The Agency intends to take appropriate regulatory action, as needed, based on its reevaluation of the Clozapine REMS.

Information on Clozapine

Clozapine (marketed as Clozaril, Fazaclo ODT, Versacloz and generics) is an antipsychotic medicine used to treat schizophrenia in patients whose symptoms are not controlled with standard antipsychotic drugs. Clozapine is also used in patients with recurrent suicidal behavior associated with schizophrenia or schizoaffective disorder.

While clozapine is beneficial for some patients, there are risks associated with this drug. Specifically, clozapine can decrease the number of neutrophils, a type of white blood cell, that function in the body to fight off infections. When neutrophils are significantly decreased, severe neutropenia may result and the body may become prone to infections. For this reason, patients taking clozapine need to have their absolute neutrophil count (ANC) monitored on a regular basis. This monitoring requirement serves as the basis for the Clozapine Risk Evaluation and Mitigation Strategy (REMS).

Clozapine REMS Program

The Clozapine REMS Programwas approved in September 2015 and is a “shared-system” program, meaning that it includes all clozapine medicines approved by the Food and Drug Administration (FDA). The Clozapine REMS Program ensures optimal patient monitoring for and management of clozapine-induced severe neutropenia, providing a centralized system for prescribers and pharmacists in managing patient risk, regardless of which clozapine product is being used. Prior to the approval of the Clozapine REMS Program, individual clozapine manufacturers operated separate patient registries.

In response to implementation challenges identified following the approval of the Clozapine REMS Program, the FDA announced, in November 2015, that the deadlines for certification of prescribers and pharmacies would be extended to help ensure that health care professionals had sufficient time to complete certification and to ensure patient access to clozapine was maintained.

We believe that most of the issues identified to date have been resolved. If prescribers and pharmacies experience problems while attempting to become certified, they should contact the Clozapine REMS Call Center at 844-267-8678.

In an effort to provide timely clozapine information to prescribers, pharmacies, patients, and distributors, the FDA will post any related updates on clozapine and the Clozapine REMS Program on this page.

Related Resources

If you have questions or concerns about the Clozapine REMS Program or its website please contact FDA at druginfo@fda.hhs.gov, 1-855-543-3784 or 301-796-3400.

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