Introduction: Clozapine is an atypical antipsychotic drug approved for treatment-resistant schizophrenia (TRS). Despite its high efficacy for TRS, clozapine is associated with several serious adverse effects, such as neutropenia and diabetes, so it requires vigilant monitoring. Severe anemia has also been documented as a rare but serious complication with an unclear mechanism. We present a case report of severe anemia potentially associated with zinc deficiency during clozapine therapy.
Case report: A 51-year-old woman was diagnosed with TRS without physical complications. Zinc deficiency was identified as a potential contributing factor. Zinc supplementation improved her hemoglobin levels, enabling the patient to continue clozapine at a therapeutic dose. The patient has remained stable, with no recurrence of anemia.
Discussion: Clozapine is a highly effective antipsychotic, despite side effects including blood dyscrasias. While zinc deficiency is most likely to be implicated in clozapine-induced anemia, the exact mechanism remains unclear. Further research is required to explore this relationship between clozapine and zinc decrement.
Keywords: antipsychotics; clozapine; clozapine‐induced anemia; treatment‐resistant schizophrenia (TRS); zinc deficiency anemia.
© 2025 The Author(s). Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Neuropsychopharmacology.