There Is Life After the UK Clozapine Central Non-Rechallenge Database

BACKGROUND AND AIMS

In the United Kingdom, patients on clozapine whose hematological parameters fall below certain thresholds are placed on the Central Non-Rechallenge Database (CNRD), meaning that they cannot be prescribed clozapine again except under exceptional circumstances. This practice was discontinued in the United States in 2015 by expanding the hematological monitoring guidelines, allowing more patients to receive clozapine. Our objective was to investigate the implications this policy change would have on clozapine utilization in the United Kingdom.

METHODS

This was an observational, retrospective analysis of patients registered on the CNRD in a large mental health trust. The first objective was to compare the number of patients placed on the CNRD under the United Kingdom and the US Food and Drug Administration (FDA) criteria. The second objective was to explore the hematological and clinical outcomes of CNRD patients. The third objective was to investigate the hematological outcomes of patients rechallenged on clozapine after nonrechallengeable status.

RESULTS

One hundred and fifteen patients were placed on CNRD from 2002 to 2019, of whom 7 (6%) met the equivalent criteria for clozapine discontinuation under the FDA guidelines. Clinical outcomes, as measured by the Clinical Global Impression-Severity scale, were worse 3 months after clozapine cessation than on clozapine (t = -7.4862; P < .001). Sixty-two (54%) patients placed on CNRD were rechallenged. Fifty-nine of those (95%) were successfully rechallenged; 3 patients were placed back on CNRD, only one of which would have had to stop clozapine again under FDA criteria.

CONCLUSION

Implementation of the updated FDA's monitoring criteria in the United Kingdom would significantly reduce clozapine discontinuation due to hematological reasons. The evidence suggests an urgent need for revising the UK clozapine monitoring guidelines to improve outcomes in treatment-resistant schizophrenia.

Clozapine reinitiation following a "red result" secondary to chemotherapy

We describe a case of a patient whose clozapine was discontinued after a "red result" following R-CHOP (rituximab with cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone) chemotherapy for large B-cell lymphoma. In some cases, manufacturers grant permission, on compassionate grounds, for clozapine to be continued or reinitiated following assessment by their consultant hematologist. Other than a recent case report, there is not much literature surrounding this medical issue. However, since the two leading causes of mortality in schizophrenia are cancer and cardiac disease, this is not an uncommon occurrence. Clinicians are reluctant to prescribe clozapine in view of its side-effect profile, despite its proven efficacy for managing treatment-resistant schizophrenia. The alternative is to prescribe two antipsychotics to manage symptoms. This approach may be associated with increased side effects, and evidence for actual benefits is scant. The consequences were disastrous in this case, as the individual not only relapsed following clozapine discontinuation, but the therapy for this treatable form of lymphoma had to be delayed. He was eventually admitted to an inpatient unit after having been stable for 15 years. We managed to stabilize him with olanzapine and aripiprazole which enabled the heme-oncology group to resume R-CHOP therapy with filgrastim (granulocyte colony-stimulating factor). Even so, he continued to exhibit severe psychotic symptoms, with religious delusions and auditory hallucinations. We therefore applied for permission to rechallenge him on clozapine. Permission was granted when protocol conditions were met, and reinitiation went without any adverse events. The patient's symptoms showed improvement within a few weeks, and the other antipsychotics were discontinued once clozapine was titrated up to 300 mg. The decision to reinitiate clozapine following a red result is not to be taken lightly, but needs to be considered in terms of the risks versus benefits. More literature surrounding this issue would be of great benefit to clinicians, patients, and their families.