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Reminder about requirements for clozapine therapy

June 1, 2016

ACP recently received a report about a community pharmacy dispensing clozapine to a patient without contacting a clozapine registry, or ensuring it was appropriate for the patient to be dispensed this medication. The patient previously experienced a significant adverse reaction to clozapine therapy and was assigned “non-challengeable status”.

Pharmacists are reminded that patients who are initiated on clozapine therapy – along with their treating physician and dispensing pharmacist – must be enrolled in a clozapine registry. Since 2003, there have been three manufacturers of clozapine, (Novartis, Apotex and GenCan) each with its own registry.

When patients enroll, the registry assigns a patient-specific number for tracking and monitoring. If a patient switches to a different treating physician, pharmacy, or laboratory, a modification form must be sent to the appropriate registry to notify them of the change.

Patients must undergo regular hematological tests (i.e., complete blood count or CBC) to monitor their white blood cell count (WBC) and absolute neutrophil count (ANC). The pharmacist must ensure that a CBC has been performed within the appropriate time frame before dispensing clozapine. Weekly CBC is required of all patients on clozapine for the first 26 weeks, after which the frequency may be reduced to every two weeks.

When dispensing clozapine for the first time, in addition to verifying the patient’s hematological status, the pharmacist should verify the patient’s non-rechallengable status. Pharmacists can call the clozapine networks to assess previous clozapine exposure and risk of agranulocytosis. If a patient is found to be non-rechallengable, they must not be restarted on any brand of clozapine.

Please note that the three different brands of clozapine are not interchangeable. Health Canada specifically states that pharmacists must not switch a patient from one brand of clozapine to another unless they obtain a new, registry-specific patient registration form completed by the prescribing physician

Novartis (Clozaril Support and Assistance Network (CSAN)
Tel: (514) 631-6775
Fax: 1-800-465-1312
General Info:

Apotex (Apo-Clozapine Risk Management Program)
Tel: 1-877-276-2569
Fax: 1-866-836-6778
General Info:

Tel: 1-800-497-9592