Thrombocytopenia associated with olanzapine: A case report and review of literature

There is limited literature on olanzapine-associated thrombocytopenia. In this report, we present a case of a 32-year-old female, suffering from persistent delusional disorder who had thrombocytopenia (46,000/mm(3)) with the use of olanzapine 25 mg/day, 6 weeks after starting medication. Blood film did not reveal any evidence of any dysplastic cells, disturbance in the count of other cell lines, and autoimmune workup including antinuclear antibodies and anti-neutrophil cytoplasmic antibodies were found to be negative. Given no other etiology, olanzapine was gradually tapered, and platelet counts were monitored. Reduction in the dose of olanzapine led to an improvement in platelet counts which reached the normal range after complete stoppage of olanzapine. In view of continued psychotic symptoms, she was started on clozapine and which was gradually increased to 200 mg/day with biweekly monitoring of total platelet counts before each increment in the dose of clozapine. Thrombocytopenia did not recur with use of clozapine. With clozapine, her psychosis improved by nearly 60%. A review of literature revealed only eight case reports supporting the association of olanzapine and thrombocytopenia.