Reversible Neutropenia With Olanzapine Following Clozapine-Induced Neutropenia

Haematological toxicity of drugs used in psychiatry

“…On withdrawal of clozapine he was again given olanzapine, but this time developed neutropenia during the third week of treatment. The WCC rose to normal on withdrawal of olanzapine (Thangadurai et al, 2006). Quetiapine, which is structurally related to both clozapine and to olanzapine (Figure 3), can also cause neutropenia/agranulocytosis, but does so only rarely despite being prescribed at a higher weight for weight basis than olanzapine (Cowan and Oakley, 2007;Croarkin and Rayner, 2001).…”

Clozapine-induced late leukopenia

“…There have been two case reports in the literature to suggest an increased risk of blood dyscrasia on other antipsychotics following a previous episode on clozapine [8,9]. The choice of medication should be based both on clinical need and the identified risk of dyscrasia for each medication.…”

“…This evidence base is not sufficient to allow the development of any guidelines. It is recommended in one of the case reports that patients who develop clozapine-induced blood dyscrasia should have haematological monitoring regularly during treatment with other antipsychotics, even if they have not had any haematological adverse effects with other antipsychotics in the past [9]. Our decision for this patient is to continue managing her on a combination therapy and to monitor her FBC regularly.…”

Haematological monitoring in psychiatry

“…To the best of our knowledge, there have been reports of two patients with blood dyscrasia with olanzapine and risperidone who previously developed blood dyscrasia during clozapine treatment [2,3]. This means that patients who develop clozapine-induced blood dyscrasia should have haematological monitoring regularly during treatment with other antipsychotics, even if they have not had any haematological adverse effects with that drug in the past [3].…”