Successful clozapine continuation during chemotherapy for the treatment of malignancy: a case report

The need for chemotherapy treatment in a cancer patient who uses clozapine raises a clinical dilemma because both therapies can cause agranulocytosis. A 45-year-old male diagnosed with schizophrenia used clozapine together with zuclopenthixol for more than 15 years. Non-Hodgkin's lymphoma was treated with chemotherapy twice, and clozapine was continued during both courses of chemotherapy. Agranulocytosis did not occur during the first treatment. During the second treatment, agranulocytosis occurred, but was attributed to chemotherapy, and blood counts recovered spontaneously. Successful concomitant use of clozapine and cancer chemotherapy is based on a limited number of case reports. However, two case reports describe persistent neutropenia or agranulocytosis, possibly related to this combination. Clozapine should only be continued during cancer chemotherapy if favoured by the risk-to-benefit ratio.