Are there any known hematological side-effects during treatment with olanzapine (Zyprexa)? Is there

Fråga: Are there any known hematological side-effects during treatment with olanzapine (Zyprexa)? Is there a known cross-reaction with other neuroleptics with regard to the risk for developing hematological side-effects? Background: A man with schizophrenia has previously for years been treated with zuclopenthixol, although with compliance problems. In 1995 blood samples revealed leukocytes and granulocytes in the lower range. A hematological investigation was initiated but was not completed. After that the patient has been treated during a period with risperidone. Since February 1997 he is treated with olanzapine and in May thioridazine was added. He still has leukocytes and granulocytes in the lower range.

Sammanfattning: Hematological side effects are rare for neuroleptics except for clozapine. A reversible decrease in leukocytes and neutrophils may occur during olanzapine treatment. There is no conclusive documentation concerning the risk for hematological cross-reactions between olanzapine and other neuroleptics.

Svar: Hematological reactions such as leukopenia, agranulocytosis, trombocytopenia and hemolytical anemia are known but rare side-effects of neuroleptics (1). Whether this is a hypersensitivity reaction or a bone-marrow depression effect is not yet fully understood (1,2). In The Swedish catalogue of approved medical products no hematological side-effects are stated for zuclopenthixol but are mentioned for risperidone (moderate decrease in neutrophils and trombocytes), olanzapine (asymptomatic hematological changes) and thioridazine (leucopenia, agranulocytosis).

The statement in The Swedish catalogue of approved medical products concerning olanzapine is referring to a slight but reversible decrease in leukocytes and neutrophils during treatment with olanzapine (3).

There is no documentation concerning the risk for a hematological cross-reaction between olanzapine and classic neuroleptics. Cross-reactions between atypical neuroleptics are scarce. Thirty-two patients who had decreased leukocytes and/or neutrophils on clozapine treatment had been exposed to olanzapine. There was no significant risk for development of leucopenia, however, the material was too small to be conclusive.

In this case the patient had leukocytes and granulocytes in the lower range before treatment was started with olanzapine. This contradicts a causal relationship between the hematological changes in this patient and the olanzapine treatment. Other causes should be considered eg hematological disease or that the normal granulocyte value, in this patient, might be low.