Quetiapine-induced leucopenia and thrombocytopenia.

Antipsychotic drugs can cause neutropenia, which can progress to life-threatening agranulocytosis if drug therapy is not interrupted. The newer atypical antipsychotics are reputedly without adverse hematological effects. Quetiapine is a recently introduced atypical antipsychotic. It is a dibenzothiazepine derivative and shows similarities with clozapine in that it is characterized by high 5-HT(2)-relative-to-DA(2) receptor affinity. Although adverse effects are usually mild, the author reports here a case of leucocytopenia and thrombocytopenia with quetiapine treatment that required its discontinuation.