Clozapine induced pancytopenia leading to severe sepsis: an unusual early complication

BACKGROUND: Clozapine is a second generation antipsychotic used to treat resistant schizophrenia and other psychotic illnesses. Leucopenia or agranulocytosis is a rare side effect of this drug. Pancytopenia is an extremely rare side effect of clozapine and literature review showed only one such case in where the pancytopenia developed several months after starting clozapine together with other antipsychotic drugs. CASE PRESENTATION: A 26-year-old Sri Lankan male was admitted with fever for 3 days. Apart from generalized body aches there were no other significant symptoms. His blood counts showed pancytopenia. He was being treated for a resistant schizophrenia and clozapine was started only 4 weeks before. Common causes for pancytopenia were excluded, and a diagnosis of clozapine induced pancytopenia was made. He was managed in the intensive care unit with broad spectrum antibiotics, antifungals and granulocyte colony stimulating factors. He made a complete recovery after 4 weeks. CONCLUSION: This is a rare and probably the first reported case of early onset clozapine induced pancytopenia complicated by severe sepsis recovering completely.